SIST EN 15936:2012
(Main)Sludge, treated biowaste, soil and waste - Determination of total organic carbon (TOC) by dry combustion
Sludge, treated biowaste, soil and waste - Determination of total organic carbon (TOC) by dry combustion
This European Standard specifies two methods for the determination of total organic carbon (TOC) in sludge, treated biowaste, soil, waste and sediment samples containing more than 1 g carbon per kg of dry matter (0,1 %). For sludge, treated biowaste and soil only Method A is validated.
Schlamm, behandelter Bioabfall, Boden und Abfall - Bestimmung des gesamten organischen Kohlenstoffs (TOC) mittels trockener Verbrennung
Diese Europäische Norm legt zwei Verfahren zur Bestimmung des gesamten organischen Kohlenstoffs (TOC) in Schlamm, behandeltem Bioabfall, Boden, Abfall und Sedimentproben fest, die mehr als 1 g Kohlenstoff je Kilogramm Trockenmasse (0,1 %) enthalten.
Für Schlamm, behandelten Bioabfall und Boden ist nur das Verfahren A validiert.
Boue, biodéchet traité, sol et déchets - Détermination de la teneur en carbone organique total (COT) par combustion sèche
La présente Norme européenne spécifie deux méthodes de détermination de la teneur en carbone organique total (COT) dans des échantillons de boue, de sédiments, de déchets, de biodéchets et de sol contenant plus de 1 g de carbone par kg de matière sèche (0,1 %).
Le charbon et le charbon de bois (carbone élémentaire) et les composés de carbone inorganique à l’exception des carbonates, sont considérés comme du carbone organique s’ils sont présents dans l’échantillon.
Blato, obdelani biološki odpadki, tla in odpadki - Določevanje celotnega organskega ogljika (TOC) s suhim sežigom
Ta evropski standard določa dve metodi za določitev skupnega organskega ogljika (TOC) v blatu, predelanih bioloških odpadkih, prsti, odpadkih in vzorcih usedlin, ki vsebujejo več kot 1 g ogljika na kg suhe snovi (0,1 %). Za blato, predelane biološke odpadke in prst je potrjena samo metoda A.
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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.ORWQHJDSchlamm, behandelter Bioabfall, Boden und Abfall - Bestimmung des gesamten organischen Kohlenstoffs (TOC) mittels trockener VerbrennungBoue, biodéchet traité, sol et déchets - Détermination de la teneur en carbone organique total (COT) par combustion sècheSludge, treated biowaste, soil and waste - Determination of total organic carbon (TOC) by dry combustion13.030.20Liquid wastes. SludgeICS:Ta slovenski standard je istoveten z:EN 15936:2012SIST EN 15936:2012en,fr,de01-december-2012SIST EN 15936:2012SLOVENSKI
STANDARD
SIST EN 15936:2012
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 15936
August 2012 ICS 13.030.01 English Version
Sludge, treated biowaste, soil and waste - Determination of total organic carbon (TOC) by dry combustion
Boues, bio-déchets traités, sols et déchets - Détermination de la teneur en carbone organique total (COT) par combustion sèche
Schlamm, behandelter Bioabfall, Boden und Abfall - Bestimmung des gesamten organischen Kohlenstoffs (TOC) mittels trockener Verbrennung This European Standard was approved by CEN on 24 May 2012.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 15936:2012: ESIST EN 15936:2012
EN 15936:2012 (E) 2 Contents Page Foreword .3Introduction .41 Scope .52 Normative references .53 Terms and definitions .54 Principle .55 Interferences .66 Reagents .77 Apparatus .78 Sample pretreatment .89 Procedure - Method A (Indirect method) .810 Procedure Method B (direct method) . 1111 Precision . 1312 Test report . 13Annex A (informative)
Repeatability and reproducibility data . 14Annex B (informative)
Factors influencing dry combustion methods . 17Annex C (informative)
Determination of total organic carbon (TOC) in solid samples using the suspension method . 20Bibliography . 24 SIST EN 15936:2012
EN 15936:2012 (E) 3 Foreword This document (EN 15936:2012) has been prepared by Technical Committee CEN/TC 400 “Project Committee - Horizontal standards in the fields of sludge, biowaste and soil”, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by February 2013, and conflicting national standards shall be withdrawn at the latest by February 2013. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. The preparation of this document by CEN is based on a mandate by the European Commission (Mandate M/330), which assigned the development of standards on sampling and analytical methods for hygienic and biological parameters as well as inorganic and organic determinants, aiming to make these standards applicable to sludge, treated biowaste and soil as far as this is technically feasible.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
SIST EN 15936:2012
EN 15936:2012 (E) 4 Introduction This European Standard is applicable and validated for several types of matrices as indicated in Table 1 (see also Annex A for the results of the validation). Table 1 — Matrices for which this European Standard is applicable and validated Matrix Materials used for validation Sludge Municipal sludge Biowaste Compost, Fresh Compost Soil Sludge amended soil,
Agricultural soil Waste Filter cake, Bottom ash, Electro-plating sludge, Dredged sludge, Rubble
WARNING — Persons using this European Standard should be familiar with usual laboratory practice. This European Standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any national regulatory conditions. IMPORTANT — It is absolutely essential that tests conducted according to this European Standard be carried out by suitably trained staff. SIST EN 15936:2012
EN 15936:2012 (E) 5 1 Scope This European Standard specifies two methods for the determination of total organic carbon (TOC) in sludge, treated biowaste, soil, waste and sediment samples containing more than 1 g carbon per kg of dry matter (0,1 %). For sludge, treated biowaste and soil only Method A is validated. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 15002, Characterization of waste — Preparation of test portions from the laboratory sample EN 15934, Sludge, treated biowaste, soil and waste — Calculation of dry matter fraction after determination of dry residue or water content EN 16179, Sludge, treated biowaste and soil — Guidance for sample pretreatment 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 total carbon TC quantity of carbon present in the sample in the form of organic, inorganic and elementary carbon
3.2 total inorganic carbon TIC quantity of carbon that is liberated as carbon dioxide by acid treatment 3.3 total organic carbon TOC quantity of carbon that is converted into carbon dioxide by combustion and which is not liberated as carbon dioxide by acid treatment 4 Principle 4.1 Method A (indirect procedure) In this procedure, the TOC is obtained by the difference between the results of the measurements of TC and TIC. The total carbon (TC) present in the sample is converted to carbon dioxide by combustion in an oxygen-containing gas flow free of carbon dioxide. To ensure complete combustion, catalysts and/or modifiers can be used. The released amount of carbon dioxide is measured by infrared spectrometry, thermal conductivity detection, flame ionisation detection after reduction to methane, or by gravimetry, coulometry, conductometry after absorption. SIST EN 15936:2012
EN 15936:2012 (E) 6 The TIC is determined separately from another sub-sample by means of acidification and purging of the released carbon dioxide. The carbon dioxide is measured by one of the techniques mentioned above. Alternatively, for soil the total organic carbon content may be calculated by determining the total carbon content and subtracting the carbon present as carbonate, which can be determined according to ISO 10693 (volumetric method). 4.2 Method B (direct procedure) In this procedure, the carbonates present in the sample are previously removed by treating the sample with acid. The carbon dioxide released by the following combustion step is measured by one of the techniques mentioned in 4.1 and indicates the TOC directly. 4.3 Applicability of Methods A or B Methods A and B have the same applicability for the determination of TOC and/or the determination of the TIC to TOC ratio. In samples with relatively high inorganic carbon contents method B should be applied. Method B may lead to incorrect results in the following cases: the sample contains volatile substances that evaporate during the acidification (e.g. volatile hydrocarbons from sludge of oil separators); side reactions between the sample and the acid take place (e.g. decarboxylation, volatile reaction products). NOTE The quality of results of Method B is dependent on experience and practice, especially regarding the steps before the determination of TOC. Use of automatic dispensing units regarding removal of carbonates prior to determination of TOC may improve the performance of Method B. 5 Interferences Volatile organic substances may be lost during sample preparation. If necessary, the carbon content resulting from volatile organic substances shall be determined separately. Depending on the laboratory experience with samples containing high amounts of carbonate the procedures may lead to unreliable TOC results if the TIC to TOC ratio is very high (e.g. ≥ 10). Depending on the detection method used, different interferences may occur, for instance: the presence of cyanide may interfere with the coulometric detection of TIC by modifying the pH value (dissolution of HCN); high content of halogenated compounds may lead to an overestimation of TOC when coulometric detection is used; in some cases the classical silver or copper trap can be insufficient to absorb all halides. When present, elementary carbon, carbides, cyanides, cyanates, isocyanates, isothiocyanates and thiocyanates are determined as organic carbon using the methods described in this European Standard. An interpretation of the measured value may therefore be problematic in cases where the sample contains relevant levels of the above-mentioned components. If needed, these components shall be determined separately by means of a suitable validated method and be recorded in the test report. Elementary carbon, determined separately, may be subtracted if required for the sample. If this is done this shall be reported by the laboratory.
SIST EN 15936:2012
EN 15936:2012 (E) 7 6 Reagents Use only reagents of recognized analytical grade, unless otherwise specified. Hygroscopic substances shall be stored in a desiccator. 6.1 Calcium carbonate, CaCO3. 6.2 Sodium carbonate, Na2CO3, anhydrous. 6.3 Tetrasodium ethylenediamine tetraacetate-tetra-hydrate, Na4-EDTA · 4 H2O (C10H12N2O8Na4 · 4 H2O), heated at 80 °C for 2 h. Other forms of Na4-EDTA hydrates may be used if the water content is exactly known. In these cases, the composition of the control mixtures has to be recalculated accordingly (see also 6.10 and 6.11). 6.4 Potassium hydrogen phthalate, C8H5O4K. 6.5 Acetanilide, C8H9NO. 6.6 Atropine, C17H23NO3. 6.7 Spectrographic graphite powder, C. 6.8 Sodium salicylate, C7H5O3Na. 6.9 Aluminium oxide, Al2O3, neutral, granular size < 200 µm, annealed at 600 °C. 6.10 Control mixture A prepared from sodium carbonate (6.2), Na4-EDTA · 4 H2O (6.3) and aluminium oxide (6.9) in a mass ratio of 2,34:1,00:1,97. The mixture shall be homogenized. It should contain 50,00 g/kg TIC and 50,00 g/kg TOC (e.g. 44,13 g of sodium carbonate, 18,83 g Na4-EDTA · 4 H2O, 37,04 g of aluminium oxide). 6.11 Control mixture B prepared from sodium salicylate (6.8), calcium carbonate (6.1), Na4-EDTA · 4 H2O (6.3) and aluminium oxide (6.9) in a mass ratio of 1,00:4,36:1,97:8,40. The mixture shall be homogenized. It should contain 33,3 g/kg TIC and 66,6 g/kg TOC (e.g. 6,36 g of sodium salicylate, 27,78 g of calcium carbonate, 12,50 g of Na4-EDTA · 4 H2O, 53,36 g of aluminium oxide). 6.12 Non-oxidizing mineral acid used for carbon dioxide expulsion, e.g. phosphoric acid H3PO4 (w = 85 %). NOTE Due to possible corrosion by hydrochloric acid, phosphoric acid is preferred. 6.13 Carrier gas, e.g. synthetic air, nitrogen, oxygen or argon, free of carbon dioxide and organic impurities in accordance with the manufacturer's instructions. 7 Apparatus 7.1 Precision balance, accurate to at least 0,5 % of test portion weight. 7.2 Equipment for determination of carbon in solids, with accessories. SIST EN 15936:2012
EN 15936:2012 (E) 8 7.3 Purging unit for TIC determination, for Method A only. 7.4 Crucibles or boats, made of e.g. ceramics, silica glass, silver or platinum. NOTE Tin and nickel crucibles are not acid-resistant. Tin crucibles are suitable only for Method A. 8 Sample pretreatment Pretreat the sample according to EN 16179 or EN 15002, if not otherwise specified. For soil, dried samples shall be used. Moist or paste-like samples may be mixed with aluminium oxide (6.9) until granular material is obtained and then be comminuted. In this case, the ratio of aluminium oxide to sample shall be considered in the calculation of TOC (according to 9.4 or 10.4). If samples contain – depending on the accuracy of the method – negligible amounts of volatile compounds except water, the samples may be dried. 9 Procedure - Method A (Indirect method) 9.1 Determination 9.1.1 General The mass of the test portion should be as large as possible and shall be chosen so that the liberated quantity of carbon dioxide lies within the working range of the equipment/calibration. 9.1.2 Determination of the TC The sample prepared according to Clause 8 is weighed into a suitable vessel (7.4). To minimize carbon blank values the vessel may be pre-treated by heating (in a muffle furnace or the TC apparatus itself). The sample is burned or decomposed in a flow of carrier gas containing oxygen (6.13). The combustion temperature shall be high enough to convert all carbon completely to carbon dioxide. For samples containing carbonates, which are difficult to decompose, e.g. barium carbonate, the release of the carbon dioxide may be improved by increasing the temperature or by the use of modifiers, e.g. tin, copper. The temperature range of commercially available instruments is between 900 °C and 1 500 °C. During the combustion of reactive samples explosion or fuming may be prevented by covering the sample with inert material e.g. silica sand.
The carbon dioxide released during the analysis is measured using one of the detection methods infrared spectrometry, gravimetry, coulometry, conductometry, thermal conductivity detection, flame ionisation detection after reduction to methane, or other suitable techniques, and is expressed as carbon. 9.1.3 Determination of the TIC The sample prepared according to Clause 8 is weighed into the purging unit (7.3). The system is closed gas-tight and flushed with carrier gas until no more carbon dioxide from ambient air is present. Then acid (6.12) is added and the carbon dioxide is stripped by purging or stirring and/or heating. The released carbon dioxide is transferred to the detector by the carrier gas. SIST EN 15936:2012
EN 15936:2012 (E) 9 The addition of anti-foaming agents, e.g. silicone oil, may be helpful in the case of strongly foaming samples. The addition of wetting agents, e.g. surfactants, may improve wetting of the surface of the sample. The carbon dioxide released during the gas evolution is immediately measured using one of the detection methods infrared spectrometry, gravimetry, coulometry, conductometry, thermal conductivity detection, flame ionisation detection after reduction to methane, or other suitable techniques and is expressed as carbon. TIC may alternatively be determined according to ISO 10693.
Samples containing persistent carbonates (e.g. concrete, cement) require treatment with hot acid for complete release of carbon dioxide. 9.2 Calibration If a relative method is used for detection, e.g. infrared detection, calibration is necessary. Examples of calibration substances suitable for TC are calcium carbonate (6.1), potassium hydrogen phthalate (6.4), acetanilide (6.5), atropine (6.6), spectrographic graphite powder (6.7).
Sodium carbonate (6.2) and Na4-EDTA (6.3) as well as all compounds with EDTA-structure shall not be used for TC-calibration as they are used as control substances. Sodium carbonate (6.2) or calcium carbonate (6.1) are suitable for the calibration of TIC. Other calibration substances may be used provided their suitability is checked. The following procedure should be applied for calibration: Establish the preliminary working range. Measure a minimum of five standard samples. The concentration of these standard samples shall be distributed evenly over the working range. Calculate mean values for each concentration. Carry out a linear regression analysis with the mean values and test the linearity of the calibration function (see also ISO 8466-1). The function shall be linear. Otherwise the working range shall be restricted to the linear range. If an absolute method is used for detection, e.g. coulometry, only control measurements according to 9.3 shall be carried out. This calibration should be carried out for initial validation purposes or after major changes of the equipment. 9.3 Control measurements Control measurements should be carried out using control mixture A (6.10) for the procedures according to 9.1.2. (TC) and 9.1.3 (TIC). Analysis of one concentration from the middle of the respective working range, possibly repeated two or three times, is sufficient. For the TC and TIC the mean recovery shall be between 90 % and 110 % with a coefficient of variation ≤ 5 %. Blank values shall be taken into account if necessary. If the required recoveries are not achieved, the following measures may be helpful. For TC analysis: SIST EN 15936:2012
EN 15936:2012 (E) 10 checking the homogeneity of the control mixture; checking the calibration; increasing the temperature during release of carbon dioxide; use of modifiers; For TIC analysis: optimising the stirring speed and/or the gas flow in the purging vessel; improving the gas exchange in the purging vessel; avoiding condensation in the system. 9.4 Calculation and expression of results The TC and TIC mass contents are calculated from calibration function and sample mass if relative detection methods are used, specific constants and sample mass if absolute detection methods are used. The calculation of TOC is achieved from the difference of the mean values of TC and TIC according to Formula (1): )(TICTCTOCmmfm−= (1) In case of mixing the sample with aluminium oxide (see Clause 8) a dilution factor following Formula (2) shall be used: sasmmmf+= (2) where TOCm is the TOC content as carbon in the sample expressed in grams per kilogram (g/kg); TCm is the mean value of the TC content as carbon in the sample, prepared according to Clause 8 expressed in grams per kilogram (g/kg); TICm is the mean value of the TIC content as carbon in the sample prepared according to Clause 8 expressed in grams per kilogram (g/kg); f is the dilution factor resulting from the sample preparation of the sample according to Clause 8; ms is the mass of the sample expressed in grams (g); ma is the mass of aluminium oxide expressed in grams (g). The TOC value resulting from Formula (1) is calculated on dry matter basis by Formula (3). For this purpose the water content, determined separately according to EN 15934, is used: wmm−×=100100TOCdmTOC, (3) SIST EN 15936:2012
EN 15936:2012 (E) 11 where dmTOC,m is the TOC content as carbon, calculated on dry matter basis expressed in grams per kilogram (g/kg); TOCm
is the TOC content as carbon in the sample expressed in grams per kilogram (g/kg); w
is the water content of the sample as mass fraction expressed in percent (%). The TOC content is reported as carbon on a dry matter basis. According to Formula (3) results are obtained in grams per kilogram (g/kg), but other units may be used.
10 Procedure Method B (direct method) 10.1 Determination 10.1.1 General The mass of the test portion should be as large as possible and shall be chosen so that the liberated quantity of carbon dioxide lies within the working range of the equipment/calibration. 10.1.2 Removal of the inorganic carbon and determination of the TOC The sample prepared according to Clause 8 is weighed into a suitable vessel (7.4). The vessel may be prepared by thermal treatment (in a muffle furnace or the combustion apparatus itself) to minimize carbon blank values. In order to remove the inorganic carbon prior to the determination of TOC, the sample is carefully treated with a small volume of non-oxidizing mineral acid (6.12). Add the acid slowly (dropwise) to avoid foaming and splashing of the sample. Add as little acid as possible but enough to soak the entire sample and to remove the inorganic carbon completely.
An automatic dispenser system allowing small increments of acid to be added at a time is recommended, e.g. 12 increments of 50 µl non-oxidizing acid, diluted with water (1:10) per 10 mg to 25 mg of sample. Allow at least 4 h for the complete removal of the carbon dioxide. Stirring of the sample may reduce time needed for oxidation. If moistening with the acid is difficult, the sample may be dampened beforehand with as little water as possible. The moisture may be partly removed before combustion. The temperature during this sample treatment shall not exceed 40 °C. Burn the sample in the carrier gas containing oxygen (6.13). The combustion temperature shall be high enough to convert the organic carbon completely to carbon dioxide. The use of modifiers e.g. tin, copper may increase the recovery. The temperature range of commercially available instruments is between 900 °C and 1 500 °C. During the combustion of reactive samples explosion or fuming may be prevented by covering the sample with inert material e.g. silica sand after removal of the inorganic carbon. The total carbon dioxide released during the combustion is measured using one of the detection methods infrared spectrometry, gravimetry, coulometry, conductometry, thermal conductivity detection, flame ionisation detection after reduction to methane, or other suitable techniques, and is expressed as carbon. SIST EN 15936:2012
EN 15936:2012 (E) 12 NOTE Corrosion of the combustion device may occur as a result of the acid remaining in the sample. Salt deposits may contaminate the system. 10.2 Calibration The calibration for TOC shall be done in accordance with the calibration for determination of TC (9.2). The same calibration substances can be used. 10.3 Control measurements Control measurements should be carried out using control mixture B (6.11) for the procedure according to 10.1.2. Analysis of one concentration from the middle of the respective working range, possibly repeated two or three times, is sufficient. For the TC and TIC the mean recovery shall be between 90 % and 110 % with a coefficient of variation ≤ 5 %. Blank values shall be taken into account if necessary. If the required recoveries are not achieved, the following measures may be helpful. For TOC analysis: checking the homogeneity of the control mixture; checking the calibration; increasing the combustion temperature; reducing the flow of the carrier gas; encouraging a turbulent flow in the combustion tube; using modifiers; using post-oxidation of the combustion gases by catalysts. Removal of carbonates: decreasing the drying temperature of the acidified sample; decreasing the drying time of the acidified sample; omitting the drying step. 10.4 Calculation and expression of results The TOC mass contents of the samples prepared according to Clause 8 are calculated from: calibration function and sample mass if relative detection methods are used, specific constants and sample mass if absolute detection methods are used. The TOC is calculated on dry matter basis by Formula (4). For this purpose the water content determined separately and, if necessary, the dilution factor resulting from sample preparation is used (see Formula (2)). wmfm−××=100100TOCdmTOC, (4) where SIST EN 15936:2012
EN 15936:2012 (E) 13 dmTOC,m is the TOC content as carbon, calculated on dry matter basis expressed in grams per kilogram (g/kg); TOCm
is the TOC content as carbon in the sample expressed in grams per kilogram (g/kg); w
is the water content of the sample as mass fraction expressed in percent (%); f is the dilution factor resulting from the sample preparation of the sample according to Clause 8 (see Formula (2)). The TOC content is reported as carbon on a dry matter basis. According to Formula (4) results are obtained in grams per kilogram (g/kg), but other units may be used. 11 Precision The performance characteristics of the method data have been evaluated (see Annex A and Annex C).
12 Test report The test report shall contain at least the following information: a) a reference to this European Standard (EN 15936); b) complete identification of the sample; c) the applied method (Method A or Method B); d) information on applied pretreatment procedure; e) information of determined and subtracted amount of elementary carbon, if relevant; f) expression of results, according to 9.4 or 10.4 respectively; g) any details not specified in this European Standard or which are optional, as well as any factor which may have affected the results. SIST EN 15936:2012
EN 15936:2012 (E) 14 Annex A (informative)
Repeatability and reproducibility data A.1 Materials used in the interlaboratory comparison study An interlaboratory comparison of the determination of TOC in sludge, treated biowaste and soil was carried out with 25 to 29 European laboratories on six materials in 2008. Detailed information can be found in the final report on the interlaboratory comparison study mentioned in [6]. Another validation study on the determination of TOC in waste was carried out in 2005. Table A.1 lists the types of materials tested in the study on soil, sludge and treated biowaste, Table A.2 lists the materials tested in the waste study. Table A.1 — Materials tested in the interlaboratory comparison of the determination of TOC
in sludge, treated biowaste and soil Grain size Sample Material Sludge (< 0,5 mm) Sludge 1 Mix 1 of municipal waste water treatment plant sludges from North Rhine Westphalia, Germany Sludge 2 Mix 2 of municipal waste water treatment plant sludges from North Rhine Westphalia, Germany Fine grained (< 2,0 mm) Compost 1 Fresh compost from Vienna, Austria Compost 2 Compost from Germany Soil 4 Sludge amended soil from Hohenheim, Germany Soil 5 Agricultural soil from Reading, United Kingdom
Table A.2 — Materials tested in an interlaboratory comparison of the determination of TOC in waste Grain size Sample Material < 2,0 mm Waste 1 Filter cake < 2,0 mm Waste 2 Bottom ash < 2,0 mm Waste 3 Electro Plating Sludge < 2,0 mm Waste 4 Dredged Sludge < 2,0 mm Waste 5 Rubble
SIST EN 15936:2012
EN 15936:2012 (E) 15 A.2 Interlaboratory results The statistical eva
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Sludge, treated biowaste, soil and waste - Determination of total organic carbon (TOC)
by dry combustion
Schlamm, behandelter Bioabfall, Boden und Abfall - Bestimmung des gesamten
organischen Kohlenstoffs (TOC) mittels trockener Verbrennung
Boue, biodéchet traité, sol et déchets - Détermination de la teneur en carbone organique
total (COT) par combustion sèche
Ta slovenski standard je istoveten z: prEN 15936
ICS:
13.030.20 7HNRþLRGSDGNL%ODWR Liquid wastes. Sludge
oSIST prEN 15936:2011 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN 15936:2011
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oSIST prEN 15936:2011
EUROPEAN STANDARD
DRAFT
prEN 15936
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2010
ICS 13.030.01
English Version
Sludge, treated biowaste, soil and waste - Determination of total
organic carbon (TOC) by dry combustion
Boue, biodéchet traité, sol et déchets - Détermination de la Schlamm, behandelter Bioabfall, Boden und Abfall -
teneur en carbone organique total (COT) par combustion Bestimmung des gesamten organischen Kohlenstoffs
sèche (TOC) mittels trockener Verbrennung
This draft European Standard is submitted to CEN members for second enquiry. It has been drawn up by the Technical Committee
CEN/TC 400.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations which
stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other language
made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2010 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 15936:2010: E
worldwide for CEN national Members.
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oSIST prEN 15936:2011
prEN 15936:2010 (E)
Contents Page
Foreword .4
Introduction .5
1 Scope .5
2 Normative references .6
3 Terms and definitions .6
4 Principle .6
4.1 General .6
4.2 Method A (indirect procedure) .6
4.3 Method B (direct procedure) .7
4.4 Applicability of Methods A or B .7
5 Interferences .7
6 Reagents .7
7 Apparatus .8
8 Sample pretreatment .9
9 Procedure - Method A (Indirect method) .9
9.1 Determination .9
9.1.1 General .9
9.1.2 Determination of the TC .9
9.1.3 Determination of the TIC .9
9.2 Calibration . 10
9.3 Control measurements . 10
9.4 Calculation and expression of results . 11
10 Procedure Method B (direct method) . 12
10.1 Determination . 12
10.1.1 General . 12
10.1.2 Removal of the inorganic carbon and determination of the TOC . 12
10.2 Calibration . 13
10.3 Control measurements . 13
10.4 Calculation and expression of results . 13
11 Precision . 14
12 Test report . 14
Annex A (informative) Repeatability and reproducibility data . 15
A.1 Materials used in the interlaboratory comparison study . 15
A.2 Interlaboratory results . 16
Annex B (informative) Factors influencing dry combustion methods . 18
B.1 Influence of temperature and modifiers on the decomposition of barium carbonate as an
example for a refractory compound . 18
B.2 Influence of aluminium oxide or sodium sulfate used for sample preparation for the
recovery of TOC . 18
B.3 Influence of TIC:TOC ratio on the recovery and the coefficient of variation . 19
B.4 Method A: recovery of TOC for control mixture A . 20
B.5 Method B: Influence of the temperature during the removal of inorganic carbon on the
recovery of TOC . 20
2
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Annex C (informative) Determination of total organic carbon (TOC) in solid samples using the
suspension method . 21
C.1 General . 21
C.2 Application range . 21
C.3 Basic principle of the method . 21
C.4 Reagents. 22
C.5 Apparatus . 22
C.6 Implementation . 22
C.6.1 Calibration . 22
C.6.2 Control experiments . 22
C.6.3 Determination . 23
C.7 Evaluation of the results . 23
C.7.1 General . 23
C.7.2 Blank value . 23
C.8 Method characteristics . 24
Bibliography . 25
3
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oSIST prEN 15936:2011
prEN 15936:2010 (E)
Foreword
This document (prEN 15936:2010) has been prepared by Technical Committee CEN/TC 400 “Project
Committee - Horizontal standards in the fields of sludge, biowaste and soil”, the secretariat of which is held by
DIN.
This document is currently submitted to the second CEN Enquiry.
This draft European Standard prEN 15936 was completely technically and editorially revised following the
st
comments made during the 1 CEN-Enquiry in 2009 and the discussions from CEN/TC 400/WG 4 "Inorganic
elements and compounds".
This European Standard is part of a modular horizontal approach in which this document belongs to the
analytical step.
The preparation of this document by CEN is based on a mandate by the European Commission (Mandate
M/330), which assigned the development of standards on sampling and analytical methods for hygienic and
biological parameters as well as inorganic and organic determinants, aiming to make these standards
applicable to sludge, treated biowaste and soil as far as this is technically feasible.
Until now, test methods determining properties of materials within the environmental area were prepared in
Technical Committees (TCs) working on specific products/matrices (e. g. soil, waste, sludge). However, it is
understood that many steps within individual test procedures may also be used for the analysis of various
other materials. By careful determination of these steps and selection of specific questions within these steps,
elements of the test procedure can be described in a way that can be used for a variety of matrices and
materials with certain specifications. This optimization is in line with the development among end-users of
standards. A majority of routine environmental analyses are carried out by institutions and laboratories
working under a scope that is not limited to one single environmental matrix but covers a wide variety of
matrices. Availability of standards covering more matrices contributes to the optimization of laboratory
procedures and standard maintenance costs, e. g. costs related to accreditation and recognition.
A horizontal modular approach was developed in the project 'Horizontal'. 'Modular' means that a test standard
developed in this approach concerns a specific step in assessing a property and not the whole ”chain of
measurement” (from sampling to analyses). A beneficial feature of this approach is that individual “modules”
can be replaced by improved ones without jeopardizing the standard “chain”.
The results of the desk study as well as the evaluation and validation studies have been subject to
discussions with all parties concerned in the CEN structure during the development by project 'Horizontal'.
The results of these consultations with interested parties in the CEN structure have been presented to and
discussed in CEN/TC 400.
Based on data from interlaboratory studies and consultations with interested parties within CEN member
bodies, it has been concluded that this draft standard prEN 15936 is acceptable for its intended use and is
ready for CEN enquiry.
It is recognized that standardization in the environmental field in most national standardization bodies is
organized in national standardization committees that mirror the vertical structure of technical committees in
the environmental field in CEN. The present CEN enquiry therefore asks for special attention by the NSBs to
assure that the relevant and interested parties are consulted during the CEN enquiry, i. e. to assure that one
single consolidated enquiry reply on this draft standard prEN 15936 can be presented by the NSB that covers
the entire scope of this draft standard.
4
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oSIST prEN 15936:2011
prEN 15936:2010 (E)
Introduction
This European Standard is (applicable and) validated for several types of matrices as indicated below (see
also Annex A for the results of the validation):
Table 1 — Matrices for which this European Standard is (applicable and) validated
Matrix Validated for
Sludge Municipal sludge
Biowaste Compost,
Fresh Compost
Soil Sludge amended soil,
Agricultural soil
Waste Filter cake,
Bottom ash,
Electro-plating sludge,
Dredged sludge,
Rubble
WARNING — Persons using this European Standard should be familiar with normal laboratory
practice. This European Standard does not purport to address all of the safety problems, if any,
associated with its use. It is the responsibility of the user to establish appropriate safety and health
practices and to ensure compliance with any national regulatory conditions.
IMPORTANT — It is absolutely essential that tests conducted according to this European Standard be
carried out by suitably trained staff.
1 Scope
This European Standard specifies two methods for the determination of total organic carbon (TOC) in sludge,
treated biowaste, soil, waste and sediment samples containing more than 1 g carbon per kg of dry matter
(0,1%).
Coal, charcoal and inorganic carbon compounds except carbonates will be determined as organic carbon
when present in the sample.
For sludge, treated biowaste and soil only method A is validated.
5
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2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
prEN 15934, Sludge, treated biowaste, soil and waste — Calculation of dry matter by determination of dry
residue or water content
prEN WI00400022, Sludge, treated biowaste and soil - Guidance for sample pretreatment
ISO 10693, Soil quality – Determination of carbonate content – Volumetric method
3 Terms and definitions
For the purposes of this European Standard, the following terms and definitions apply:
3.1
total carbon
TC
quantity of carbon present in the sample in the form of organic, inorganic and elemental carbon
3.2
total inorganic carbon
TIC
quantity of carbon that is liberated as carbon dioxide by acid treatment
3.3
total organic carbon
TOC
quantity of carbon that is converted into carbon dioxide by combustion and which is not liberated as carbon
dioxide by acid treatment
4 Principle
4.1 General
The TOC can be measured either by Method A (indirect procedure) or by Method B (direct procedure).
4.2 Method A (indirect procedure)
In this procedure the TOC is obtained by the difference between the results of the measurements of TC and
TIC.
The total carbon (TC) present in the un-dried sample or dried sample is converted to carbon dioxide by
combustion in an oxygen-containing gas flow free of carbon dioxide. For soil dried samples are used. To
ensure complete combustion, catalysts and/or modifiers can be used. The released amount of carbon dioxide
is measured by infrared spectrometry, gravimetry, coulometry, conductometry, thermal conductivity detection,
flame ionisation detection after reduction to methane, or other suitable techniques.
The TIC is determined separately from another sub-sample by means of acidification and purging of the
released carbon dioxide. The carbon dioxide is measured by one of the techniques mentioned above.
Alternatively, for soil the total organic carbon content may be calculated by determining the total carbon
content and subtracting the carbon present as carbonate, which can be determined according to ISO 10693
(volumetric method).
6
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4.3 Method B (direct procedure)
In this procedure the carbonates present in the un-dried or dried sample are previously removed by treating
the sample with acid. The carbon dioxide released by the following combustion step is measured by one of the
techniques mentioned in 4.2 and indicates the TOC directly.
4.4 Applicability of Methods A or B
Methods A and B have the same applicability in the terms of TOC content and/or TIC to TOC ratio. In samples
with relatively high inorganic carbon contents method B should be applied.
Method B may lead to incorrect results in the following cases:
the sample contains volatile substances that evaporate during the acidification (e.g. volatile hydrocarbons
from sludge of oil separators);
side reactions between the sample and the acid take place (e.g. decarboxylation, volatile reaction
products).
The quality of results of Method B is dependent on experience and practice, especially regarding the steps before the
determination of TOC. Use of automatic dispensing units regarding removal of carbonates prior to determination of TOC
may improve the performance of Method B.
5 Interferences
Volatile organic substances may be lost during sample preparation. If necessary, the carbon content resulting
from volatile organic substances shall be determined separately.
Depending on the laboratory experience with samples containing high amounts of carbonate the procedures
may lead to unreliable TOC results if the TIC to TOC ratio is very high (e.g. ≥ 10).
Depending on the detection method used, different interferences may occur, for instance:
the presence of cyanide can interfere with the coulometric detection of TIC by modifying the pH value
(dissolution of HCN);
high content of halogenated compounds may lead to an overestimation of TOC when coulometric
detection is used; in some cases the classical silver or copper trap can be insufficient to absorb all
halides.
When present, elemental carbon, carbides, cyanides, cyanates, isocyanates, isothiocyanates and
thiocyanates are determined as organic carbon using the methods described in this standard. An
interpretation of the measured value may therefore be problematic in cases where the sample contains
relevant levels of the above-mentioned components. If needed, these components shall be determined
separately by means of a suitable validated procedure and be recorded in the test report.
Elementary carbon, determined separately, may be subtracted if required for the sample. If this is done this
shall be reported by the laboratory.
6 Reagents
All reagents used shall be at least of analytical grade.
Hygroscopic substances shall be stored in a desciccator.
7
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prEN 15936:2010 (E)
6.1 Calcium carbonate, CaCO
.
3
6.2 Sodium carbonate, Na CO , anhydrous.
2 3
6.3 Tetrasodium ethylenediamine tetraacetate-tetra-hydrate, Na -EDTA · 4H O
4 2
(C H N O Na · 4H O), heated at 80 °C for 2 h.
10 12 2 8 4 2
NOTE Other forms of Na -EDTA hydrates may be used if the water content is exactly known. Then the composition
4
of the control mixtures has to be recalculated accordingly (see also 6.10 and 6.11).
6.4 Potassium hydrogen phthalate, C H O K
8 5 4
6.5 Acetanilide, C H NO.
8 9
6.6 Atropine, C H NO
.
17 23 3
6.7 Spectrographic graphite powder, C.
6.8 Sodium salicylate, C H O Na.
7 5 3
6.9 Aluminium oxide, Al O , neutral, granular size < 200 µm, annealed at 600 °C.
2 3
6.10 Control mixture A prepared from sodium carbonate (6.2), Na -EDTA · 4H O (6.3) and aluminium oxide
2
4
(6.9) in a mass ratio of 2,34: 1,00:1,97.
The mixture shall be homogenized. It should contain 50,00 g/kg TIC and 50,00 g/kg TOC (e. g. 44,13 g of
sodium carbonate, 18,83 g Na -EDTA · 4H O, 37,04 g of aluminium oxide).
2
4
6.11 Control mixture B prepared from sodium salicylate (6.8), calcium carbonate (6.1), Na -EDTA · 4H O
2
4
(6.3) and aluminium oxide (6.9) in a mass ratio of 1,00:4,36:1,97:8,40.
The mixture shall be homogenized. It should contain 33,3 g/kg TIC and 66,6 g/kg TOC (e.g. 6,36 g of sodium
salicylate, 27,78 g of calcium carbonate, 12,50 g of Na -EDTA · 4H O, 53,36 g of aluminium oxide).
2
4
6.12 Non-oxidizing mineral acid used for carbon dioxide expulsion, e. g. phosphoric acid H PO (w =
3 4
85 %)
NOTE Due to possible corrosion by hydrochloric acid, phosphoric acid is preferred.
6.13 Carrier gas, e. g. synthetic air, nitrogen, oxygen or argon, free of carbon dioxide and organic impurities
in accordance with the manufacturer's instructions.
7 Apparatus
7.1 Precision balance, accurate to at least 0,5 % of test portion weight.
7.2 Equipment for determination of carbon in solids, with accessories.
7.3 Purging unit for TIC determination, for Method A only.
7.4 Crucibles or boats, made of e.g. ceramics, silica glass, silver or platinum.
NOTE Tin and nickel crucibles are not acid-resistant.
8
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8 Sample pretreatment
Pretreat the sample according to prEN WI00400022.
For soil dried samples shall be used.
Moist or paste-like samples may be mixed with aluminium oxide (6.9) until granular material is obtained and
then comminuted. In this case the ratio of aluminium oxide to sample shall be considered in the calculation of
TOC (according to 9.4 or 10.4).
If samples contain – according to the accuracy of the method – negligible amounts of volatile compounds
except water, the samples may be dried
9 Procedure - Method A (Indirect method)
9.1 Determination
9.1.1 General
The mass of the test portion should be as large as possible and shall be chosen so that the liberated quantity
of carbon dioxide lies within the working range of the equipment/calibration.
9.1.2 Determination of the TC
The sample prepared according to clause 8 is weighed into a suitable vessel (7.4). To minimize carbon blank
values the vessel may be pre-treated by heating (in a muffle furnace or the TC apparatus itself).
The sample is burned or decomposed in a flow of carrier gas containing oxygen (6.13).
The combustion temperature shall be high enough to convert all carbon completely to carbon dioxide. For
samples containing carbonates, which are difficult to decompose, e.g. barium carbonate, the release of the
carbon dioxide may be improved by increasing the temperature or by the use of modifiers, e.g. tin, copper.
The temperature range of commercially available instruments is between 900 °C and 1 500 °C.
During the combustion of reactive samples, covering the sample with inert material, e.g. silica sand, may
prevent detonation or fuming.
The carbon dioxide released during the analysis is measured using one of the detection methods infrared
spectrometry, gravimetry, coulometry, conductometry, thermal conductivity detection, flame ionisation
detection after reduction to methane, or other suitable techniques, and is expressed as carbon.
9.1.3 Determination of the TIC
The sample prepared according clause 8 is weighed into the purging unit (7.3).
The system is closed gas-tight and flushed with carrier gas until no more carbon dioxide from ambient air is
present. Then acid (6.12) is added and the carbon dioxide is stripped by purging or stirring and/or heating.
The released carbon dioxide is transferred to the detector by the carrier gas.
The addition of anti-foaming agents, e.g. silicone oil, may be helpful in the case of strongly foaming samples.
The addition of wetting agents, e.g. surfactants, may improve wetting of the surface of the sample.
9
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The carbon dioxide released during the gas evolution is immediately measured using one of the detection
methods infrared spectrometry, gravimetry, coulometry, conductometry, thermal conductivity detection, flame
ionisation detection after reduction to methane, or other suitable techniques and is expressed as carbon.
TIC may alternatively be determined according to ISO 10693.
9.2 Calibration
If a relative method is used for detection, e. g. infrared detection, calibration is necessary.
Examples of calibration substances suitable for TC are calcium carbonate (6.1), potassium hydrogen
phthalate (6.4), acetanilide (6.5), atropine (6.6), spectrographic graphite powder (6.7).
Sodium carbonate (6.2) and Na -EDTA (6.3) as well as all compounds with EDTA-structure shall not be used
4
for TC-calibration as they are used as control substances.
Sodium carbonate (6.2) or calcium carbonate (6.1) are suitable for the calibration of TIC. Other calibration
substances may be used provided their suitability is checked.
The following procedure should be applied for calibration:
Establish the preliminary working range.
Measure a minimum of five (recommended ten) standard samples at least in triplicate.
The concentration of these standard samples shall be distributed evenly over the working range.
Calculate mean values for each concentration.
Carry out a linear regression analysis with the mean values and test the linearity of the calibration
function (see also ISO 8466-1).
The function shall be linear. Otherwise the working range must be restricted to the linear range.
If an absolute method is used for detection, e. g. coulometry, only control measurements according to 9.3
shall be carried out.
This calibration should be carried out for initial validation purposes or after major changes of the equipment.
9.3 Control measurements
Control measurements should be carried out using control mixture A (6.10) for the procedures according to
9.1.2. (TC) and 9.1.3 (TIC). Analysis of one concentration from the middle of the respective working range,
possible repeated two or three times, is sufficient. For the TC and TIC the mean recovery shall be between
90 % and 110 % with a coefficient of variation ≤ 5%.
Blank values shall be taken into accou
...
SLOVENSKI STANDARD
oSIST prEN 15936:2009
01-julij-2009
7ODEODWRRGSDGNLLQELRRGSDGNL'RORþHYDQMHFHORWQHJDRUJDQVNHJDRJOMLND
72& VVXKLPVHåLJRP
Soil, sludge, waste, and treated biowaste - Determination of total organic carbon (TOC)
by dry combustion
Schlamm, Boden, Abfall und behandelter Bioabfall - Bestimmung des gesamten
organischen Kohlenstoffs (TOC) durch trockene Verbrennung
Sol, boue et biodéchet traité - Détermination de la teneur en carbone organique total
(COT) par combustion sèche
Ta slovenski standard je istoveten z: prEN 15936
ICS:
13.030.01 Odpadki na splošno Wastes in general
oSIST prEN 15936:2009 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN 15936:2009
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oSIST prEN 15936:2009
EUROPEAN STANDARD
DRAFT
prEN 15936
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2009
ICS
English Version
Soil, sludge, waste, and treated biowaste - Determination of total
organic carbon (TOC) by dry combustion
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/SS S99.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations which
stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other language
made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the
same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2009 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 15936:2009: E
worldwide for CEN national Members.
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oSIST prEN 15936:2009
prEN 15936:2009 (E)
Contents
Foreword . 4
Introduction . 6
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Safety remarks . 7
5 Principle . 8
5.1 General . 8
5.2 Method A (indirect procedure) . 8
5.3 Method B (direct procedure) . 8
5.4 Applicability of Methods A or B . 8
6 Interferences and sources of errors . 8
7 Reagents . 9
7.1 General . 9
7.2 Calcium carbonate . 9
7.3 Sodium carbonate. 9
7.4 Tetrasodium ethylenediamine tetraacetate-tetra-hydrate . 9
7.5 Potassium hydrogen phthalate . 9
7.6 Acetanilide . 9
7.7 Atropine . 9
7.8 Spectrographic graphite powder . 9
7.9 Sodium salicylate. 9
7.10 Aluminium oxide . 9
7.11 Control mixture A. 10
7.12 Control mixture B. 10
7.13 Non-oxidizing mineral acid . 10
7.14 Synthetic air, nitrogen, oxygen or argon . 10
8 Apparatus . 10
9 Sampling and sample pre-treatment. 10
9.1 Sampling . 10
9.2 Sample pre-treatment . 10
10 Procedure - Method A (Indirect method) . 11
10.1 Determination . 11
10.1.1 General . 11
10.1.2 Determination of the TC . 11
10.1.3 Determination of the TIC . 11
10.2 Calibration . 12
10.3 Control measurements . 12
10.4 Calculation and expression of results . 13
11 Procedure Method B (direct method) . 14
11.1 Determination . 14
11.1.1 General . 14
11.1.2 Removal of the inorganic carbon and determination of TOC . 14
11.2 Calibration . 15
11.3 Control measurements . 15
11.4 Calculation and expression of results . 15
12 Precision data . 16
13 Test report . 16
2
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Annex A (informative) Validation of dry combustion methods . 17
A.1 General. 17
A.2 Additional results of inter-laboratory studies. 18
A.2.1 Influence of temperature and modifiers on the decomposition of barium carbonate as an
example for a refractory compound . 18
A.2.2 Influence of aluminium oxide or sodium sulphate used for sample preparation on the recovery
of TOC . 18
A.2.3 Influence of TIC/TOC ratio on the recovery and the coefficient of variation . 19
A.2.4 Method A: recovery of TOC for the control mixture A (7.11) . 20
A.2.5 Method B: influence of the temperature during the removal of inorganic carbon on the
recovery of TOC . 20
Annex B (informative) . 21
B.1 Materials used in the interlaboratory study . 21
B.2 Interlaboratory results . 21
B.3 Repeatability and reproducibility . 22
Annex C (Informative) Determination of total organic carbon (TOC) in solid samples using the
suspension method . 23
C.1 General. 23
C.2 Application range . 23
C.3 Basic principle of the method . 23
C.4 Reagents . 23
C.4.1 Water used for dilution. 23
C.4.2 Potassium hydrogen phthalate . 23
C.4.3 Hydrochloric acid . 24
C.4.4 Gases . 24
C.5 Apparatus . 24
C.5.1 General. 24
C.5.2 Homogenisation . 24
C.6 Implementation . 24
C.6.1 Calibration . 24
C.6.2 Control experiments . 24
C.6.3 Determination . 24
C.7 Evaluation of the results . 25
C.7.1 General. 25
C.7.2 Blank value . 25
C.8 Method characteristics. 25
Annex D (informative) Comparison of validation results with earlier validation studies using the same
method . 26
Bibliography . 28
3
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oSIST prEN 15936:2009
prEN 15936:2009 (E)
Foreword
This document (prEN 15936:2009) has been prepared by Technical Committee CEN/SS S99 "Health, environment
and medical equipment - Undetermined", the secretariat of which is held by CMC.
The document is currently submitted to the CEN Enquiry.
This draft standard has been prepared by the European project «Horizontal » and presented to CEN/TC BTTF 151
“Horizontal Standards in the Fields of Sludge, Biowaste, and Soil”, the secretariat of which is held by DS.
Standardisation is carried out under mandate M330 given to CEN by the European Commission, and supports
essential requirements of EU Directive(s).
The standard is part of a modular horizontal approach in which this standard belongs to the analytical step.
The results of the desk study as well as the evaluation and validation studies have been subject to discussions with
all parties concerned in the CEN structure during the development by project Horizontal. The results of these
consultations with interested parties in the CEN structure have been presented to and discussed in CEN BT/TF 151.
Based on data from interlaboratory studies and consultations with interested parties within CEN member bodies, it
has been concluded that the draft standard is acceptable for its intended use and is ready for the CEN enquiry. The
matrix “waste” was included during the entire process of development of the draft standard and is according to a
resolution by TC 292 in 2008 included in the scope of the standard.
The document is technical equivalent to EN 13137 (covering the matrices waste, sludge and sediment), however,
the matric soil is included. A new method is included in Annex C describing the suspension method. Annex C is so
far informative, as a decision on including the principle in the final standard is recommended to depend on the
availability of validation.
It is recognized that standardization in the environmental field in most national standardization bodies is organized
in national standardization committees that mirror the vertical structure of technical committees in the
environmental field in CEN. The present CEN enquiry therefore asks for a special attention by the NSBs to assure
that the relevant and interested parties are consulted during the CEN enquiry, i.e. to assure that one single
consolidated enquiry reply on the draft standard can be presented by the NSB that covers the entire scope of the
draft standard.
4
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oSIST prEN 15936:2009
prEN 15936:2009 (E)
The standard is applicable and validated for several types of matrices as indicated below:
Material Validated for Reference:
(type of sample, e.g. municipal
sludge, compost)
Sludge Two samples of municipal sludge, EN 13137:2001,
Germany Characterisation of waste –
Determination of total organic
carbon (TOC) in waste, sludges
and sediments
Soil Sludge amended soil, Germany JRC report and report on
validation by project Horizontal
Agricultural soil, UK
Biowaste Compost, Vienna, Austria JRC report and report on
validation by project Horizontal
Compost, Germany
Sediment See Annex A EN 13137:2001,
Characterisation of waste –
Determination of total organic
carbon (TOC) in waste, sludges
and sediments
Waste See Annex A EN 13137:2001,
Characterisation of waste –
Determination of total organic
carbon (TOC) in waste, sludges
and sediments
5
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oSIST prEN 15936:2009
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Introduction
This draft standard is one of a number of draft standards developed and validated in the European project
'Horizontal' financed by the EU commission and EU member states. The project “Horizontal” was conducted by a
European Consortium under the management by ECN, The Netherlands. This draft standard was presented by the
project Horizontal to CEN/BT TF 151 in June 2008 with a view to be formally adopted as European Standard under
CEN rules.
The standardisation by CEN is carried out on a mandate by the European Commission (Mandate M/330). The
mandate considers standards on sampling and analytical methods for hygienic and biological parameters as well
as inorganic and organic determinants. It was the aim of the initiative to develop standards that are suitable for a
wide range of environmental materials and lead to equivalent results as far as this is technically feasible.
Until now test methods determining properties of materials within the environmental area were prepared in
Technical Committees (TCs) working on specific products/matrices (soil, waste, sludge etc). However, it is
recognized that many steps in test procedures can be used in test procedures for other products/matrices. By
careful determination of these steps and selection of specific questions within these steps, elements of the test
procedure can be described in a way that can be used for more matrices and materials with certain specifications.
This optimization is in line with the development among end-users of standards. A majority of routine environmental
analyses are carried out by institutions and laboratories working under a scope which is not limited to one single
environmental matrix but covers a wide variety of matrices. Availability of standards covering more matrices
contributes to the optimization of laboratory procedures and standard maintenance costs, e.g. cost related to
accreditation and recognition.
A horizontal modular approach was developed in the project 'Horizontal'. 'Modular' means that a test standard
developed in this approach concerns a specific step in assessing a property and not the whole ” chain of
measurement” (from sampling to analyses). A beneficial feature of this approach is that “modules” can be replaced
by better ones without jeopardizing the standard “chain”.
The modules that relates to this standard are specified in section 2 - Normative references.
1 Scope
This European Standard specifies two methods for the determination of total organic carbon (TOC) in sludge,
sediment, waste, biowaste and soil samples containing more than 1 g carbon per kg of dry matter (0,1%).
Coal and charcoal (elemental carbon) and inorganic carbon compounds except carbonates will be determined as
organic carbon when present in the sample.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text, and the publications are listed hereafter. For
dated references, subsequent amendments to or revisions of any of these publications apply to this European
Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the
publication referred to applies (including amendments).
ISO 8466-1, Water quality - Calibration and evaluation of analytical methods and estimation of performance
characteristics - Part 1: Statistical evaluation of the linear calibration function
CSS99031 Sludge, treated biowaste, and soils in the landscape – Sampling – Framework for the preparation and
application of a sampling plan
CSS99058 Sludge, treated biowaste, and soils in the landscape – Sampling – Part 1: Guidance on selection and
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application of criteria for sampling under various conditions
CSS99057 Sludge, treated biowaste, and soils in the landscape – Sampling – Part 2: Guidance on sampling
techniques
CSS99032 Sludge, treated biowaste, and soils in the landscape – Sampling - Part 3: Guidance on sub-sampling in
the field
CSS99059 Sludge, treated biowaste, and soils in the landscape – Sampling – Part 4: Guidance on procedures for
sample packaging, storage, preservation, transport and delivery
CSS99060 Sludge, treated biowaste, and soils in the landscape – Sampling – Part 5: Guidance on the process of
defining the sampling plan
CSS99034 Soil, sludge, and treated biowaste – Pre-treatment for solid samples
CSS99022 Soil, sludge, waste, and treated biowaste – Determination of dry matter – Gravimetric method
ISO 10693, Soil quality – Determination of carbonate content – Volumetric method
ISO 3733, Petroleum products and bituminous materials - Determination of water - Distillation method
ISO 6296, Petroleum products - Determination of water - Potentiometric Karl Fischer titration method
3 Terms and definitions
For the purposes of this European Standard, the following terms and definitions apply:
3.1
Total Carbon (TC)
quantity of carbon present in the sample in the form of organic, inorganic and elemental carbon according to this
standard
3.2
Total Inorganic Carbon (TIC)
quantity of carbon that is liberated as carbon dioxide by acid treatment according to this standard
3.3
Total Organic Carbon (TOC)
quantity carbon that is converted into carbon dioxide by combustion according to this standard and which is not
liberated as carbon dioxide by acid treatment according to this standard
4 Safety remarks
Samples may be liable to fermentation and may be infectious. Due to this it is recommended to handle these
samples with special care. The gases, which may occur due to the microorganisms activities, are potentially
flammable. Excessive pressure build-up may cause the sample container to burst, potentially resulting in the
formation of infectious aerosols and contaminated shrapnel.
Harmful compounds may arise during the combustion process and during the acid treatment. The user has to take
appropriate precautions (e.g. activated carbon filters) to avoid these getting into the laboratory environment.
Samples with a high organic content may explode at introduction into the furnace. Using less sample material or
covering the sample with inert material can reduce this risk.
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5 Principle
5.1 General
The TOC can be measured either by Method A (indirect procedure) or by Method B (direct procedure).
5.2 Method A (indirect procedure)
In this procedure the TOC is obtained by the difference between the results of the measurements of TC and TIC.
The total carbon (TC) present in the un-dried sample or dried sample is converted to carbon dioxide by combustion
in an oxygen-containing gas flow free of carbon dioxide. For soil dried samples are used. To ensure complete
combustion, catalysts and/or modifiers can be used. The released amount of carbon dioxide is measured by
infrared spectrometry, gravimetry, coulometry, conductometry, thermal conductivity detection, flame ionisation
detection after reduction to methane, or other suitable techniques.
The TIC is determined separately from another sub-sample by means of acidification and purging of the released
carbon dioxide. The carbon dioxide is measured by one of the techniques mentioned above. Alternatively, for soil
the total organic carbon content may be calculated by determining the total carbon content and subtracting the
carbon present as carbonate, which can be determined according to ISO 10693 (volumetric method).
5.3 Method B (direct procedure)
In this procedure the carbonates present in the un-dried or dried sample are previously removed by treating the
sample with acid. The carbon dioxide released by the following combustion step is measured by one of the
techniques mentioned in 5.2 and indicates the TOC directly.
5.4 Applicability of Methods A or B
Methods A and B have the same applicability in the terms of TOC content and/or TIC to TOC ratio. In samples with
relatively high inorganic carbon contents method B is preferred.
Method B may lead to incorrect results in the following cases:
the sample contains volatile substances that evaporate during the acidification (e.g. volatile hydrocarbons from
sludge of oil separators);
side reactions between the sample and the acid take place (e.g. decarboxylation, volatile reaction products).
The quality of results of Method B is dependent on experience and practise, especially regarding the steps before
the determination of TOC. Use of automatic dispensing units regarding removal of carbonates prior to
determination of TOC may improve the performance of Method B.
6 Interferences and sources of errors
Volatile organic substances may be lost during sample preparation. If necessary, the carbon content resulting from
volatile organic substances shall be determined separately.
Depending on the laboratory experience with samples containing high amounts of carbonate the procedures may
lead to unreliable TOC results if the TIC to TOC ratio is very high (e.g. ≥ 10).
Depending on the detection method used, different interferences may occur, for instance:
the presence of cyanide can interfere with the coulometric detection of TIC by modifying the pH value
(dissolution of HCN);
high content of halogenated compounds may lead to an overestimation of TOC when coulometric detection is
used; in some cases the classical silver or copper trap can be
...
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