ISO/TC 147/SC 2 - Physical, chemical and biochemical methods

This document specifies a method for the determination of the dissolved anions chlorate, chloride and chlorite in water with low contamination (e.g. drinking water, raw water or swimming pool water). The diversity of the appropriate and suitable assemblies and the procedural steps depending on them permit a general description only. For further information on the analytical technique, see Bibliography.

This document specifies various calibration strategies for physicochemical and chemical analytical methods and specifies the calculation of analytical results. It defines the general context for linear calibration so that individual standards dealing with analytical methods for the examination of water quality can make reference to it.

This document specifies a method for the quantification of twelve microcystin variants (microcystin-LR, -LA, -YR, -RR, -LY, -WR, -HtyR, -HilR, -LW, -LF, [Dha7]-microcystin-LR, and [Dha7]-microcystin-RR) in drinking water and freshwater samples between 0,05 µg/l to 1,6 µg/l. The method can be used to determine further microcystins, provided that analytical conditions for chromatography and mass spectrometric detection has been tested and validated for each microcystin. Samples are analysed by LC-MS/MS using internal standard calibration. This method is performance based. The laboratory is permitted to modify the method, e.g. increasing direct flow injection volume for low interference samples or diluting the samples to increase the upper working range limit, provided that all performance criteria in this method are met. Detection of microcystins by high resolution mass spectrometry (HRMS) as an alternative for tandem mass spectrometry (MS/MS) is described in Annex A. An alternative automated sample preparation method based on on-line solid phase extraction coupled to liquid chromatography is described in Annex B. When instrumental sensitivity is not sufficient to reach the method detection limits by direct flow injection, a solid phase extraction clean-up and concentration step is described in Annex C.

This document specifies a method for the determination of certain cyclic volatile methylsiloxanes (cVMS) in environmental water samples with low density polyethylene (LDPE) as a preservative and subsequent liquid-liquid extraction with hexane containing 13C-labeled cVMS as internal standards. The extract is then analysed by gas chromatography-mass spectrometry (GC-MS). NOTE Using the 13C-labeled, chemically identical substances as internal standards with the same properties as the corresponding analytes, minimizes possible substance-specific discrimination in calibrations. Since these substances are least soluble in water, they are introduced via the extraction solvent hexane into the system.

This document specifies a method for the determination of alkylmercury compounds in filtered water samples by gas chromatography-mass spectrometry after phenylation and solvent extraction. This method is applicable to determination of individual methylmercury (MeHg) and ethylmercury (EtHg) compounds in surface water and waste water. The method can be applied to samples containing 0,2 μg/l to 10 μg/l of each compound as mercury mass. Depending on the matrix, the method may also be applicable to higher concentrations after suitable dilution of the sample or reduction in sample size.

This document specifies operationally defined methods for the determination of total cyanide in various types of water such as drinking water, ground water, surface water, wastewaters, metallurgical processing tailings reclaim solution, heap leach barren solution, mill slurry tailings filtrate and leaching solutions, with cyanide concentrations from 5 µg/l to 2 000 mg/l expressed as cyanide ions in the undiluted sample. The range of application can be extended by reducing the sensitivity (Figure A.1.). NOTE ISO 2080:2008, 3.105, defines free cyanide. The concentration of total cyanide as defined in ISO 2080:2008, 3.191 includes free cyanide, cyanide complexed with metals in solution as cyanide anion, but not necessarily all of the metal cyanide complexes present as determined by a specified analytical method. In this method, six suitable mass concentration ranges from 5 µg/l to 50 µg/l, from 50 µg/l to 500 µg/l, from 0,5 mg/l to 5 mg/l, from 5 mg/l to 50 mg/l, from 50 mg/l to 500 mg/l and from 500 mg/l to 2 000 mg/l are described.

This document specifies a multi‑parameter method for the determination of total organic carbon (TOC), total nitrogen (TNb) and total phosphorus (TP) in drinking water, raw water, ground water, surface water, sea water, saline water, process water, domestic and industrial wastewater, after a chemical oxidation process. It is applicable to both dissolved and bound suspended materials. The method allows for determination of TOC, TN and TP. The lower and upper working ranges for these parameters are dependent upon instrument conditions (for example sample volume, reaction chemistry amounts) and can be adjusted for a wider range. Typical measurement ranges are shown in Figures C.1 to C.3. The analysis procedure is carried out instrumentally by a single oxidation process. Dissolved nitrogen gas is not included in the TNb measurement in this method. When present in the sample, elemental carbon, cyanate and thiocyanate will be included in the TOC result.

This document specifies a method for the determination of selected perfluoroalkyl and polyfluoroalkyl substances (PFAS) in non‑filtrated waters, for example drinking water, natural water (fresh water and sea water) and waste water containing less than 2 g/l solid particulate material (SPM) using liquid chromatography-tandem mass spectrometry (LC‑MS/MS). The compounds monitored by this method are typically the linear isomers. The group of compounds determined by this method are representative of a wide variety of PFAS. The analytes specified in Table 1 can be determined by this method. The list can be modified depending on the purpose for which the method is intended. The lower application range of this method can vary depending on the sensitivity of the equipment used and the matrix of the sample. For most compounds to which this document applies ≥0,2 ng/l as limit of quantification can be achieved. Actual levels can depend on the blank levels realized by individual laboratory. The applicability of the method to further substances, not listed in Table 1, or to further types of water is not excluded, but is intended to be validated separately for each individual case. NOTE 1 PFAS is used in this document to describe the analytes monitored. Many of the compounds in Table 1 are perfluoroalkyl and are also considered polyfluoroalkyl substances. NOTE 2 The linear PFAS isomers are specified in this document. The branched isomers can be present in environmental samples, especially for PFOS. Annex E provides an example of an analytical approach to the chromatographic and spectroscopic separation of individual isomers.

This document specifies the criteria for mass spectrometric identification of target compounds in water samples and is applicable to environmental samples in general. This document is intended to be used in conjunction with standards developed for the determination of specific compounds. If a standard method for analysing specific compounds includes criteria for identification, those criteria are followed.

This document specifies the criteria for developing an in-house mass spectrometry-based method for quantitative analysis of multiple subgroups of organic substances in the scope of physical-chemical analysis of water. This document supplements ISO/TS 13530 which provides guidance on the initial characterization of the measurement performances, by providing details to select the test matrix and internal standards and criteria for analyte and internal standard recoveries. This document is not intended as a substitute for the currently applicable analytical standards dedicated to organic compounds but as a resource bringing additional characterization elements.

This document specifies a method for the quantitative determination of the sum of short-chain polychlorinated n-alkanes also known as short-chain polychlorinated paraffins (SCCPs) in the carbon bond range n-C10 to n-C13 inclusive, in mixtures with chlorine mass fractions ("contents") between 50 % and 67 %, including approximately 6 000 of approximately 8 000 congeners. This method is applicable to the determination of the sum of SCCPs in unfiltered surface water, ground water, drinking water and waste water using gas chromatography-mass spectrometry with electron capture negative ionization (GC-ECNI-MS). Depending on the capability of the GC-ECNI-MS instrument, the concentration range of the method is from 0,1 µg/l or lower to 10 µg/l. Depending on the waste water matrix, the lowest detectable concentration is estimated to be > 0,1 µg/l. The data of the interlaboratory trial concerning this method are given in Annex I.

This document specifies representative materials suitable for the determination of the performance characteristics, including uncertainty, during the initial assessment of a quantitative method, used in a laboratory, for physico-chemical water analysis. This document focuses on five main types of water: — waters intended for consumption (5.2); — natural waters (5.3); — waste waters (5.4); — marine waters (5.5); — recreational waters (5.6). NOTE Other more specific or less common types of water can be incorporated in any of the above types provided appropriate justifications. The characteristics of the standard matrix are compatible with the characteristics of the samples handled.

This document specifies the following semi-quantitative methods for the assessment of transparency of waters: a) measurement of visual range using the transparency testing tube (applicable to transparent and slightly cloudy water), see Clause 4; b) measurement of visual range in the upper water layers using the transparency testing disc (especially applicable to surface, bathing water, waste water and often used in marine monitoring), see 5.1; c) measurement of visibility by divers in a destined depth, see 5.2. NOTE The quantitative methods using optical turbidimeters or nephelometers are described in ISO 7027-1.

This document specifies continuous flow analysis (CFA) methods for the determination of orthophosphate in the mass concentration range from 0,01 mg/l to 1,00 mg/l P, and total phosphorus in the mass concentration range from 0,10 mg/l to 10,0 mg/l P. The method includes the digestion of organic phosphorus compounds and the hydrolysis of inorganic polyphosphate compounds, performed either manually, as described in ISO 6878 and in References [4], [5] and [7], or with an integrated ultraviolet (UV) digestion and hydrolysis unit. This document is applicable to various types of water, such as ground, drinking, surface, leachate and waste water. The range of application can be changed by varying the operating conditions. This method is also applicable to the analysis of seawater, but with changes in sensitivity by adapting the carrier and calibration solutions to the salinity of the samples. It is also applicable to analysis using 10 mm to 50 mm cuvettes depending on the desired range. For extreme sensitivity, 250 mm and 500 mm long way capillary flow cells (LCFCs) can be used. However, the method is not validated for these two uses. Changes in sensitivity and calibration solutions could be required. Annex A provides examples of a CFA system. Annex B gives performance data from interlaboratory trials. Annex C gives information of determining orthophosphate-P and total-P by CFA and tin(II) chloride reduction.

This document specifies a method for the determination of the dissolved fraction of selected active pharmaceutical ingredients and transformation products, as well as other organic substances (see Table 1) in drinking water, ground water, surface water and treated waste water. The lower application range of this method can vary depending on the sensitivity of the equipment used and the matrix of the sample. For most compounds to which this document applies, the range is ≥ 0,025 µg/l for drinking water, ground water and surface water, and ≥ 0,050 µg/l for treated waste water. The method can be used to determine further organic substances or in other types of water (e.g. process water) provided that accuracy has been tested and verified for each case, and that storage conditions of both samples and reference solutions have been validated. Table 1 shows the substances for which a determination was tested in accordance with the method. Table E.1 provides examples of the determination of other organic substances.

This document specifies a method for the determination of total organic carbon (TOC), dissolved organic carbon (DOC), total bound nitrogen (TNb) and dissolved bound nitrogen (DNb) in the form of free ammonia, ammonium, nitrite, nitrate and organic compounds capable of conversion to nitrogen oxides under the conditions described. The procedure is carried out instrumentally. NOTE Generally the method can be applied for the determination of total carbon (TC) and total inorganic carbon (TIC), see Annex A. The method is applicable to water samples (e.g. drinking water, raw water, ground water, surface water, sea water, waste water, leachates). The method allows a determination of TOC and DOC ≥ 1 mg/l and TNb and DNb ≥ 1 mg/l. The upper working range is restricted by instrument-dependent conditions (e.g. injection volume). Higher concentrations can be determined after appropriate dilution of the sample. For samples containing volatile organic compounds (e.g. industrial waste water), the difference method is used, see Annex A. Cyanide, cyanate and particles of elemental carbon (soot), when present in the sample, can be determined together with the organic carbon. The method is not appropriate for the determination of volatile, or purgeable, organic carbon under the conditions described by this method. Dissolved nitrogen gas (N2) is not determined.

This document specifies a method for the quantitative determination of selected cyclic volatile methylsiloxanes (cVMS) in non-filtered water samples by purge and trap extraction with isotope dilution gas chromatography-mass spectrometry (GC-MS). This method is applicable to the determination of individual cVMS, including: — octamethylcyclotetrasiloxane (D4); — decamethylcyclopentasiloxane (D5); — dodecamethylcyclohexasiloxane (D6); in surface water, ground water, and wastewater. It can be applied to samples within the concentration range of 0,01 µg/l to 1 µg/l of each of the target compounds. Depending on the matrix, the method may also be applicable to higher concentrations ranging from 1 µg/l to 100 µg/l after suitable dilution of the sample or reduction in sample size.

This document specifies operationally defined methods for the determination of available WAD cyanide in various types of water such as drinking, ground, and surface, waters, and metallurgical processing tailings reclaim, heap leach barren, mill slurry tailings and leaching solutions, with cyanide concentrations from 5 µg/l to 2 000 mg/l expressed as cyanide ions in the undiluted sample. The range of application can be changed by varying the operation conditions, e.g. by using a different injection volume, thicker membrane, detector response, etc. NOTE ISO 2080:2008, 3.105, defines free cyanide. The concentration of available WAD cyanide includes free cyanide and some of the metals complexed in solution as determined by a specified analytical method but not all of the metal complexes present in total cyanide (3,191). In this method, six suitable mass concentration ranges from 5 µg/l to 50 µg/l, from 50 µg/l to 500 µg/l, from 0,5 mg/l to 5 mg/l, from 5 mg/l to 50 mg/l, from 50 mg/l to 500 mg/l and from 500 mg/l to 2 000 mg/l are described.

ISO/TS 19620:2018 specifies a method primarily developed for the determination of inorganic arsenic species (arsenite (As(III)) and arsenate (As(V)) dissolved in a sample after a preservation process in waters with a low total organic carbon content such as potable water, tap water, surface waters, ground waters and rain waters. Information is provided on the determination of potentially relevant organo-arsenic species such as methylarsonic acid (MMA) and dimethylarsinic acid (DMA) which may be encountered at very low levels in natural surface waters. The linear working dynamic range depends on the operating conditions and the method of detection used; under standard conditions, it typically ranges from 0,5 µg/l to 50 µg/l for each species. Samples containing arsenic at concentrations higher than the linear dynamic range can be analysed after suitable dilution. This method is based on high performance liquid chromatography separation of arsenic species with either inductively coupled mass spectrometry (ICP-MS) or hydride generation atomic fluorescence spectrometry (HG-AFS) as a method of detection. The sensitivity of this method depends on the method of detection and the instrumental operating conditions selected. The limit of quantification (LOQ) of the method also depends on the operating conditions of the analytical system used and the extent of the calibration range used. LOQ examples for As(III) and As(V) are provided; LOQs are generally less than 1 µg/l. ISO/TS 19620:2018 does not apply to arsenobetaine and other organic arsenic species which are not present in natural water samples.

ISO 20595:2018 specifies a method for the determination of selected volatile organic compounds in water (see Table 1). This comprises among others volatile halogenated hydrocarbons as well as gasoline components (BTXE, TAME, MTBE and ETBE). The method is applicable to the determination of volatile organic compounds (see Table 1) in drinking water, groundwater, surface water and treated waste water in mass concentrations >0,1 µg/l. The lower application range depends on the individual compound, the amount of the blank value and the matrix.

ISO 7393-2:2017 specifies a method for the determination of free chlorine and total chlorine in water, readily applicable to lab- and field-testing. It is based on measurement of the absorption, the red DPD colour complex in a photometer or the colour intensity by visual comparison of the colour with a scale of standards that is regularly calibrated. This method is appropriate for drinking water and other waters, where additional halogens like bromine, iodine and other oxidizing agents are present in almost negligible amounts. Seawater and waters containing bromides and iodides comprise a group for which special procedures are to be carried out. This method is in practice applicable to concentrations, in terms of chlorine (Cl2), from, for example, 0,000 4 mmol/l to 0,07 mmol/l (e.g. 0,03 mg/l to 5 mg/l) total chlorine. For higher concentrations, the test portion is diluted. Commonly, the method is applied as a field method with mobile photometers and commercially available ready-for-use reagents (liquid reagents, powders and tablets). It is essential that those reagents comply with minimum requirements and contain the essential reagents and a buffer system suitable to adjust the measurement solution to a pH range of typically 6,2 to 6,5. If there is doubt that water samples have uncommon pH values and/or buffer capacities, the user has to check and, if necessary, to adjust the sample pH to the required range. The pH of the sample is within the range of pH 4 and 8. Adjust, if necessary, with sodium hydroxide solution or sulfuric acid before the test. A procedure for the differentiation of combined chlorine of the monochloramine type, combined chlorine of the dichloramine type and combined chlorine in the form of nitrogen trichloride is presented in Annex A. In Annex C, a procedure is presented for the determination of free and total chlorine in drinking and other low polluted waters, for disposable planar reagent-filled cuvettes using a mesofluidic channel pump/colorimeter.

ISO 19340:2017 specifies a method for the determination of dissolved perchlorate in water (e.g. drinking water, mineral water, raw water, surface water, partially treated water or swimming pool water, waste water from drinking/swimming pool water treatment plants). Appropriate pre-treatment of the sample (e.g. matrix elimination) allows a direct determination of perchlorate ≥ 1 µg/l. The working range is restricted by the ion-exchange capacity of the separator column. Dilution of the sample to the working range can be necessary.

ISO/TS 15923-2:2017 specifies methods for the automatic determination of chromium(VI), fluoride, total alkalinity, total hardness, calcium, magnesium, iron, iron(II), manganese and aluminium with photometric determination using a discrete analysis system. The field of application is water (ground, potable, surface, waste, eluates and boiler water). The method can also be applied to marine waters with matrix matching of standard and control solutions. Note that some parameters, notably iron, manganese and aluminium and possibly chromium(VI), calcium and magnesium may not be completely quantified if the sample contains particulates. Samples can be digested in acid, as long as the buffering capacity of the reaction mixture is not exceeded. Such procedures are beyond the scope of ISO/TS 15923-2:2017, which is best suited to the determination of dissolved metals following on-site filtration.

ISO 17294-2:2016 specifies a method for the determination of the elements aluminium, antimony, arsenic, barium, beryllium, bismuth, boron, cadmium, caesium, calcium, cerium, chromium, cobalt, copper, dysprosium, erbium, gadolinium, gallium, germanium, gold, hafnium, holmium, indium, iridium, iron, lanthanum, lead, lithium, lutetium, magnesium, manganese, mercury, molybdenum, neodymium, nickel, palladium, phosphorus, platinum, potassium, praseodymium, rubidium, rhenium, rhodium, ruthenium, samarium, scandium, selenium, silver, sodium, strontium, terbium, tellurium, thorium, thallium, thulium, tin, tungsten, uranium and its isotopes, vanadium, yttrium, ytterbium, zinc and zirconium in water (for example, drinking water, surface water, ground water, waste water and eluates). Taking into account the specific and additionally occurring interferences, these elements can also be determined in digests of water, sludges and sediments (for example, digests of water as described in ISO 15587‑1 or ISO 15587‑2). The working range depends on the matrix and the interferences encountered. In drinking water and relatively unpolluted waters, the limit of quantification (xLQ) lies between 0,002 µg/l and 1,0 µg/l for most elements. The working range typically covers concentrations between several pg/l and mg/l depending on the element and pre-defined requirements. The quantification limits of most elements are affected by blank contamination and depend predominantly on the laboratory air-handling facilities available on the purity of reagents and the cleanliness of glassware. The lower limit of quantification is higher in cases where the determination suffers from interferences (see Clause 5) or memory effects (see ISO 17294‑1:2004, 8.2).

ISO/TS 17951-1:2016 specifies a method for the determination of fluoride in waters, waste waters and effluents by flow injection analysis (FIA). Any insoluble or complexed fluoride is converted to fluoride ion by a manual distillation procedure from sulfuric/phosphoric acid. Fluoride ion in the distillate is measured using flow analysis with lanthanum alizarin complexone and spectrometric detection. This method is applicable to industrial waste waters, effluents, surface waters, ground waters, leachates. It is not recommended for drinking waters where a distillation step is not required. In ISO/TS 17951-1:2016, two working ranges are described: - working range I: 0,1 mg/l to 1 mg/l; - working range II: 1 mg/l to 10 mg/l. The specification of the calibration solutions are to be adapted accordingly.

ISO/TS 17951-2:2016 specifies a method for the determination of fluoride in waters, waste waters and effluents by continuous flow analysis (CFA). Any insoluble or complexed fluoride is converted to fluoride ion by an automated continuous flow distillation procedure from sulfuric/phosphoric acid. Fluoride ion in the distillate is measured using flow analysis with lanthanum alizarin complexone and spectrometric detection. This method is applicable to industrial waste waters, effluents, surface waters, ground waters, leachates. When this method is applied to the analysis of drinking water, a heater and a distillation unit is unnecessary. Some drinking water contains high concentration of aluminium and iron. In the case of drinking water, ISO/TS 17951-2:2016 is appropriate to drinking water with low interferences. It is not applicable to samples which contain large amount of suspended matter. In ISO/TS 17951-2:2016, two working ranges are described: - working range I: 0,1 mg/l to 1,0 mg/l; - working range II: 1,0 mg/l to 10 mg/l. The specification of the calibration solutions are to be adapted accordingly.

ISO 7027-1:2016 specifies two quantitative methods using optical turbidimeters or nephelometers for the determination of turbidity of water: a) nephelometry, procedure for measurement of diffuse radiation, applicable to water of low turbidity (for example drinking water); b) turbidimetry, procedure for measurement of the attenuation of a radiant flux, more applicable to highly turbid waters (for example waste waters or other cloudy waters). Turbidities measured according to the first method are presented as nephelometric turbidity units (NTU). The results typically range between Turbidity measured by the second method is expressed in formazin attenuation units (FAU), results typically range between 40 FAU and 4 000 FAU.

ISO 18635:2016 specifies a method for the quantitative determination of the sum of short-chain polychlorinated n-alkanes also known as short-chain polychlorinated paraffins (SCCPs) in the carbon bond range, n-C10 to n-C13, inclusive in mixtures with chlorine mass fractions ("contents") between 50 % and 67 %, including approximately 6 000 of approximately 8 000 congeners. This method is applicable to the determination of the sum of SCCPs in sediment and suspended (particulate) matter, sewage sludge, and soil using gas chromatography-mass spectrometry with electron capture negative ionization (GC-ECNI-MS). Depending on matrix and the detection capabilities of the GC-ECNI-MS, the method can be applied to samples containing, e.g. 0,03 µg/g to 3 µg/g sum of SCCPs.

ISO 17943:2016 specifies a method for the determination of volatile organic compounds (see Table 1). This comprises, for example, halogenated hydrocarbons, trihalogenated methanes, gasoline components (such as BTEX, MTBE, and ETBE), naphthalene, 2-ethyl-4-methyl-1,3-dioxolane, and highly odorous substances like geosmin and 2-methylisoborneol in drinking water, ground water, surface water, and treated waste water, by means of headspace solid-phase micro-extraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS). The limit of determination depends on the matrix, on the specific compound to be analysed, and on the sensitivity of the mass spectrometer. For most compounds to which this International Standard applies, it is at least 0,01 µg/l. Validation data related to a concentration range between 0,02 µg/l and 2,6 µg/l have been demonstrated in an interlaboratory trial. Additional validation data derived from standardization work show applicability of the method within a concentration range from 0,01 µg/l to 100 µg/l of individual substances. All determinations are performed on small sample amounts (e.g. sample volumes of 10 ml).

ISO 18191:2015 specifies a spectrophotometric determination of the pHt of sea water on the total hydrogen ion concentration pH scale using the indicator dye m-cresol purple. The total hydrogen ion concentration, [H+]t, is expressed as moles per kilogram of sea water. The method is suitable for assaying oceanic levels of pHt 7,4 to 8,2 for normal sea water of practical salinity ranging from 20 to 40.

ISO/TS 16780:2015 specifies a method for the determination of polychlorinated naphthalenes (PCNs), where "poly" means "mono" to "octa", in waters and waste waters [containing less than 2 g/l solid particulate material (SPM)] using high resolution gas chromatography?high resolution mass spectrometry (HRGC?HRMS). NOTE 1 The congeners analysed by this method are listed in Table 1. The working range of the method is 20 pg/l to 8 ng/l. The method is optimized for PCNs, but can be modified to include other coplanar compounds such as polychlorinated dioxins and furans (PCDDs/PCDFs) and dioxin-like tetra- to heptachlorinated biphenyls (dlPCBs). This method can be used to determine PCNs in other matrices (e.g. biota, sediments, air); however, additional clean-up steps and techniques can be necessary for samples with high organic loadings. Low resolution mass spectrometry (LRMS) and mass spectrometry?mass spectrometry (MS?MS) can be used. NOTE 2 LRMS and MS?MS conditions are summarized in Annex A. Both LRMS and MS?MS can be less selective than HRMS and there is a possibility of bias due to interfering compounds if these techniques are used. The detection limits and quantification levels in this method are dependent on the level of interferences as well as instrumental limitations. NOTE 3 The minimum levels (ML) in Table 4 are the levels at which the PCNs can typically be determined with no interferences present. This method is performance based. The analyst is permitted to modify the method, e.g. to overcome interferences, provided that all performance criteria in this method are met. NOTE 4 The requirements for establishing method validation or equivalency are given in Clause 9.

ISO 17690:2015 specifies methods for the determination of available free cyanide at pH 6 in various types of water (such as ground, drinking, surface, leachate, waste water, and metallurgical processing waste water) with cyanide concentrations from 5 µg/l to 500 µg/l expressed as cyanide ions in the undiluted sample. The range of application can be changed by varying the operation conditions, e.g. by using a different injection volume.

ISO 16308:2014 specifies a method for the determination of dissolved fraction of glyphosate and its major metabolite, aminomethylphosphonic acid (AMPA), in drinking water, ground water, and surface water at concentrations of 0,03 µg/l to 1,5 µg/l. It does not apply to marine or salty water. This method can be applicable to other types of waters, provided the method is validated for each case.

ISO 17289:2014 specifies an optical method for the determination of dissolved oxygen in water using a sensor working on the basis of fluorescence quenching. Measurement can be made either as a concentration of oxygen in milligrams per litre, percentage saturation (% dissolved oxygen), or both. Depending on the instrument used, detection limits of 0,1 mg/l or 0,2 mg/l can be reached according to the manufacturer's manual. Most instruments permit measurement of values higher than 100 %, i.e. supersaturation. NOTE Supersaturation is possible when the partial pressure of oxygen is higher than in air. Especially in case of strong algae growth, supersaturation up to 200 % and more is possible. If waters with a saturation higher than 100 % are measured, it is essential to make arrangements to prevent the outgassing of oxygen during the handling and measurement of the sample. Similarly, it is important that the transport of oxygen into the sample is prevented if the saturation is below 100 %. The method is suitable for measurements made in the field and for continuous monitoring of dissolved oxygen as well as measurements made in the laboratory. It is one of the preferred methods for highly coloured and turbid waters, and also for analysis of waters not suitable for the Winkler titration method because of iron- and iodine-fixing substances, which can interfere in the iodometric method specified in ISO 5813. The method is suitable for drinking waters, natural waters, waste waters, and saline waters. If used for saline waters such as sea or estuarine waters, a correction for salinity is essential for concentration measurement of oxygen.

ISO 17378-2:2014 specifies a method for the determination of arsenic and antimony. The method is applicable to drinking water, surface water, ground water, and rain water. The approximate linear application range of ISO 17378-2:2014 for both elements is from 0,5 µg/l to 20 µg/l. Samples containing higher concentrations than the application range can be analysed following appropriate dilution. Generally sea water is outside the scope of ISO 17378-2:2014. Sea water samples can be analysed using a standard additions approach providing that this is validated for the samples under test. The method is unlikely to detect organo-arsenic and organo-antimony compounds. The sensitivity of this method is dependent on the selected operating conditions.

ISO 17378-1:2014 specifies a method for the determination of arsenic and antimony. The method is applicable to drinking water, surface water, ground water and rain water. The linear application range of ISO 17378-1:2014 is from 0,02 µg/l to 100 µg/l. Samples containing arsenic or antimony at higher concentrations than the application range can be analysed following appropriate dilution. Generally sea water is outside the scope of ISO 17378-1:2014. Sea water samples can be analysed using a standard additions approach providing that this is validated for the samples under test. The method is unlikely to detect organo-arsenic compounds or organo-antimony compounds. The sensitivity of this method is dependent on the selected operating conditions.

ISO 15923-1:2013 specifies methods for the automatic performance of spectrophotometric and turbidimetric analyses with a discrete analysis system for determining ammonium, nitrate, nitrite, chloride, orthophosphate, sulfate, and silicate. The field of application is ground, potable, surface, waste, eluates, and boiler water.

ISO/TS 17379-2:2013 specifies a method for the determination of selenium. The method is applicable to drinking water, surface water, ground water, and rain water. The dynamic range of ISO/TS 17379-2:2013 is approximately 0,5 µg/l to 20 µg/l. Samples containing selenium at higher concentrations than the application range can be analysed following appropriate dilution. The method is unlikely to detect organoselenium compounds. The sensitivity of this method is dependent on the selected operating conditions. It is important to use high purity reagents in all cases with minimum levels of selenium.

ISO/TS 17379-1:2013 specifies a method for the determination of selenium. The method is applicable to drinking water, surface water, ground water, and rain water. The application range of ISO/TS 17379-1:2013 is from 0,02 µg/l to 100 µg/l. Samples containing selenium at higher concentrations than the application range can be analysed following appropriate dilution. The method is unlikely to detect organoselenium compounds. The sensitivity of this method is dependent on the operating conditions selected.

ISO 5814:2012 specifies an electrochemical method for the determination of dissolved oxygen in water by means of an electrochemical cell which is isolated from the sample by a gas permeable membrane. Measurement can be made either as a concentration of oxygen in milligrams per litre, percentage saturation (% dissolved oxygen) or both. The method measures oxygen in water corresponding to 1 % to 100 % saturation. However, most instruments permit measurement of values higher than 100 %, i.e. supersaturation. The method measures oxygen in water with a saturation higher than 100 %, when special arrangements to prevent the outgassing of oxygen during the handling and measurement of the sample are made. The method is suitable for measurements made in the field and for continuous monitoring of dissolved oxygen, as well as measurements made in the laboratory. It is the preferred method for highly coloured and turbid waters, and also for analysis of waters not suitable for the Winkler titration method because of iron- and iodine-fixing substances, which can interfere in the iodometric method specified in ISO 5813. The method is suitable for drinking waters, natural waters, waste waters, and saline waters. If used for saline waters, such as sea or estuarine waters, a correction for salinity is essential.

ISO 14403-1:2012 specifies methods for the determination of cyanide in various types of water (such as ground, drinking, surface, leachate, and waste water) with cyanide concentrations from 2 µg/l to 500 µg/l expressed as cyanide ions in the undiluted sample. The range of application can be changed by varying the operation conditions, e.g. by diluting the original sample or using a different injection volume. In ISO 14403-1:2012, a suitable mass concentration range from 20 µg/l to 200 µg/l is described. Seawater can be analysed with possible changes in sensitivity and adaptation of the reagent and calibration solutions to the salinity of the samples.

ISO 14403-2:2012 specifies methods for the determination of cyanide in various types of water (such as ground, drinking, surface, leachate, and waste water) with cyanide concentrations usually from 2 µg/l to 500 µg/l expressed as cyanide ions in the undiluted sample. The range of application can be changed by varying the operation conditions, e.g. by diluting the original sample or changing the pathlength of the flow cell. In this method, a suitable mass concentration range from10 µg/l to 100 µg/l is described. Seawater can be analysed with possible changes in sensitivity and adaptation of the reagent and calibration solutions to the salinity of the samples.

This International Standard specifies methods for the estimation of measurement uncertainty of chemical and physicochemical methods in single laboratories based on validation data and analytical quality control results obtained within the field of water analysis. NOTE 1 The principles of the estimation of uncertainty specified in this International Standard are consistent with the principles described in ISO/IEC Guide 98-3. In this International Standard, the quantification of measurement uncertainty relies on performance characteristics of a measurement procedure obtained from validation and the results of internal and external quality control. NOTE 2 The approaches specified in this International Standard are mainly based on QUAM[11], NEN 7779[8], Nordtest TR 537[10], and Eurolab TR 1[9]. NOTE 3 This International Standard only addresses the evaluation of measurement uncertainty for results obtained from quantitative measurement procedures. The uncertainties associated with results obtained from qualitative procedures are not considered.

ISO 12846:2012 specifies two methods for the determination of mercury in drinking, surface, ground, rain and waste water after appropriate pre-digestion. For the first method, an enrichment step by amalgamation of the Hg on, for example, a gold/platinum adsorber is used. For the second method, the enrichment step is omitted. The choice of method depends on the equipment available, the matrix and the concentration range of interest. Both methods are suitable for the determination of mercury in water. The method with enrichment commonly has a practical working range from 0,01 µg/l to 1 µg/l. The mean limit of quantification (LOQ) reported by the participants of the validation trial was 0,008 µg/l. This information on the LOQ gives the user of ISO 12846:2012 an orientation and does not replace the estimation of performance data from laboratory specific data. It has to be considered that it is possible to achieve lower LOQs with specific instrumentation (e.g. single mercury analysers). The method without enrichment commonly has a practical working range starting at 0,05 µg/l. The LOQ reported by the participants of the validation trial was 0,024 µg/l. It is up to the user, based on the specific application, to decide whether higher concentrations are determined by omitting the enrichment step and/or by diluting the sample(s). The sensitivity of both methods is dependent on the selected operating conditions. Another possibility for the determination of extremely low Hg concentrations down to 0,002 µg/l without pre-concentration is the application of atomic fluorescence spectrometry (see ISO 17852). Specific atomic-absorption mercury analysers allow determinations down to 0,010 µg/l without pre-concentration. In general, the determination of trace concentrations of Hg by AAS (or AFS) is dependent on clean operating conditions in the laboratory and on the use of high-purity chemicals with negligible low-Hg blanks. Note that ISO 12846:2012 may be applied to industrial and municipal waste water after an additional digestion step performed under appropriate conditions and after suitable method validation. A potential sample stability issue (mercury loss) for anaerobic reducing industrial effluents has to be considered thoroughly.

This Technical Specification specifies a method for the determination by gas chromatography with mass spectrometric detection (GC-MS) of polycyclic hydrocarbons and pesticide residues in drinking water and ground water at mass concentrations above 0,005 μg/l and surface water and waste water at mass concentrations above 0,01 μg/l (for each single compound). This method can apply to non-polar substances other than polycylic aromatic hydrocarbons (PAH) and pesticide residues. However, it is necessary to verify the applicability of this method for these compounds. NOTE 1 A potentially suitable method for this verification is specified in ISO/TS 13530.[3] This Technical Specification can be used for samples containing up to 150 mg/l of suspended matter. NOTE 2 Determination of PAH using GC-MS lies within the scope of ISO 28540.[9]

ISO 7887:2011 specifies four different methods, designated A to D, for the examination of colour. The previously most employed method for assessment of water colour in water treatment plants, limnological surveys, etc. was based on the hexachloroplatinate scale. Methods C and D are harmonized with this traditional procedure. Method A involves examination of apparent colour by visually observing a water sample in a bottle. This gives only preliminary information, for example for use in field work. Only the apparent colour can be reported. Method B involves determination of the true colour of a water sample using optical apparatus and is applicable to raw and potable water and to industrial water of low colour. A subclause on interferences is included. Method C involves determination of the true colour of a water sample using optical apparatus for comparison with hexachloroplatinate concentration at wavelength, λ = 410 nm. A subclause on interferences is included. Method D involves determination of colour by visual comparison with hexachloroplatinate standard solutions and can be applied to raw and drinking water. A subclause on interferences is included. Methods A and B are appropriate if the colour hue of the sample differs from the hue of the matching solution. When stating the result, the procedure used (methods A to D) is also recorded.

ISO 28540:2011 specifies a method for the determination of at least 16 selected PAH (see Table 1) in drinking water and ground water in mass concentrations above 0,005 µg/l and surface water in mass concentrations above 0,01 µg/l (for each individual compound). ISO 28540:2011 can be used for samples containing up to 150 mg/l of suspended matter. This method is, with some modification, also suitable for the analysis of waste water. It is possible that this method is applicable to other PAH, provided the method is validated for each case.

ISO 11206:2011 specifies a method for the determination of dissolved bromate in water (e.g. drinking water, mineral water, raw water, surface water, partially treated water or swimming pool water). Appropriate pretreatment of the sample (e.g. dilution) allows determination of bromate at concentrations ³0,5 µg/l. The working range is restricted by the ion‑exchange capacity of the separator column. Dilution of the sample to the bromate working range can be necessary.

ISO 11349:2010 defines a method for the determination of lipophilic substances of low volatility in water using gravimetry. The method is applicable to all kinds of water and allows the determination of low‑volatility lipophilic substances which are suspended, emulsified, or dissolved, in concentrations of about 10 mg/l to 500 mg/l. Above this value, the test portion is diluted appropriately. The method is not applicable to water with a separate oil layer.

ISO 27108:2010 specifies a method for the determination of the dissolved amount of selected plant treatment agents and biocide products in drinking water, ground water and surface water by solid‑phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC‑MS). The limit of determination depends on the matrix, on the specific compound to be analysed and on the sensitivity of the mass spectrometer. For most plant treatment agents and biocides to which ISO 27108:2010 applies, it is at least 0,05 µg/l. Validation data related to a concentration range between 0,05 µg/l and 0,3 µg/l have been demonstrated in an interlaboratory trial. This method may be applicable to other compounds not explicitly covered by ISO 27108:2010 or to other types of water. However, it is necessary to verify the applicability of this method for these special cases.