CEN/TS 16320:2012
(Main)Fertilizers - Determination of trace elements - Determination of mercury by vapour generation (VG) after aqua regia dissolution
Fertilizers - Determination of trace elements - Determination of mercury by vapour generation (VG) after aqua regia dissolution
This Technical Specification specifies a method for the determination of the content of mercury in fertilizers after extraction with aqua regia and the detection of mercury by vapour generation (VG) coupled to an atomic absorption spectrometer or an inductively coupled plasma atomic emission spectrometer. A limit of quantification of 0,01 mg/kg is to be expected.
Düngemittel - Bestimmung von Elementspuren - Bestimmung von Quecksilber mit Verdampfungstechnik (VG) nach Königswasseraufschluss
Diese Technische Spezifikation legt ein Verfahren zur Bestimmung von Quecksilber in Düngemitteln mittels Verdampfungstechnik (VG), gekoppelt mit Atomabsorptionsspektrometer oder Atomemissionsspektrometer mit induktiv gekoppeltem Plasma nach Königswasseraufschluss fest. Die Bestimmungsgrenze wird bei 0,01 mg/kg erwartet.
Engrais - Dosage des éléments traces - Détermination du mercure par génération de vapeur (VG) après digestion à l'eau régale
Cette spécification technique spécifie une méthode permettant de déterminer, après extraction à l’eau régale,
la teneur en mercure dans les engrais par détection de mercure par génération de vapeur (VG) couplée à un
spectromètre d’absorption atomique ou un spectromètre d’émission atomique avec plasma à couplage
inductif. Une limite de quantification de 0,01 mg/kg doit être attendue.
Gnojila - Določevanje elementov v sledovih - Določevanje živega srebra s tehniko hladnih par po raztapljanju v zlatotopki
Ta tehnična specifikacija določa metodo za določevanje vsebnosti živega srebra v gnojilih po ekstrakciji z zlatotopko in določevanje živega srebra s tehniko hladnih par (VG) z atomskim absorpcijskim spektrometrom ali atomskim emisijskim spektrometrom z induktivno sklopljeno plazmo. Pričakuje se meja kvantifikacije 0,01 mg/kg.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-junij-2012
*QRMLOD'RORþHYDQMHHOHPHQWRYYVOHGRYLK'RORþHYDQMHåLYHJDVUHEUDVWHKQLNR
KODGQLKSDUSRUD]WDSOMDQMXY]ODWRWRSNL
Fertilizers - Determination of trace elements - Determination of mercury by vapour
generation (VG) after aqua regia dissolution
Düngemittel und Calcium-/Magnesium-Bodenverbesserungsmittel - Bestimmung von
Elementspuren - Bestimmung von Quecksilber mit Verdampfungstechnik (VG) nach
Königswasseraufschluss
Engrais - Dosage des éléments traces - Détermination du mercure par génération de
vapeur (VG) après digestion à l'eau régale
Ta slovenski standard je istoveten z: CEN/TS 16320:2012
ICS:
65.080 Gnojila Fertilizers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
TECHNICAL SPECIFICATION
CEN/TS 16320
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
April 2012
ICS 65.080
English Version
Fertilizers - Determination of trace elements - Determination of
mercury by vapour generation (VG) after aqua regia dissolution
Engrais - Dosage des éléments traces - Détermination du Düngemittel - Bestimmung von Elementspuren -
mercure par génération de vapeur (VG) après digestion à Bestimmung von Quecksilber mit Verdampfungstechnik
l'eau régale (VG) nach Königswasseraufschluss
This Technical Specification (CEN/TS) was approved by CEN on 30 January 2012 for provisional application.
The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.
CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.
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, 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 Ref. No. CEN/TS 16320:2012: E
worldwide for CEN national Members.
Contents Page
Foreword .3
1 Scope .4
2 Normative references .4
3 Terms and definitions .4
4 Principle .4
5 Sampling and sample preparation .4
6 Reagents .4
7 Apparatus .6
8 Procedure .6
9 Calculation and expression of the results . 10
10 Precision . 12
11 Test report . 14
Annex A (informative) Results of the inter-laboratory test . 15
Bibliography . 16
Foreword
This document (CEN/TS 16320:2012) has been prepared by Technical Committee CEN/TC 260 “Fertilizers
and liming materials”, the secretariat of which is held by DIN.
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.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this Technical Specification: 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, Turkey and the United Kingdom.
1 Scope
This Technical Specification specifies a method for the determination of the content of mercury in fertilizers
after extraction with aqua regia and the detection of mercury by vapour generation (VG) coupled to an atomic
absorption spectrometer or an inductively coupled plasma-atomic emission spectrometer. A limit of
quantification of 0,01 mg/kg is to be expected.
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 1482-2, Fertilizers and liming materials — Sampling and sample preparation — Part 2: Sample
preparation
EN 12944-1:1999, Fertilizers and liming materials and soil improvers — Vocabulary — Part 1: General terms
EN 12944-2:1999, Fertilizers and liming materials and soil improvers — Vocabulary — Part 2: Terms relating
to fertilizers
EN ISO 3696, Water for analytical laboratory use — Specification and test methods (ISO 3696)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 12944-1:1999 and EN 12944-2:1999
apply.
4 Principle
Mercury is extracted from the sample with aqua regia and conventional boiling. The concentration of mercury
in the extract is measured by (cold) vapour generation (VG) coupled to a suitable detector, such as an atomic
absorption spectrometer (AAS) or an inductively coupled plasma-atomic emission spectrometer (ICP-AES).
5 Sampling and sample preparation
Sampling is not part of the methods specified in this Technical Specification. A recommended sampling
method is given in EN 1482-1.
Sample preparation shall be carried out in accordance with EN 1482-2.
6 Reagents
Use only reagents of recognized analytical grade.
Commercially available stock solutions shall be replaced according to the specifications from the supplier or
after one year if prepared in the laboratory from available salts. Standard solutions shall be renewed monthly
as a general rule.
6.1 Water conforming to grade 2 of EN ISO 3696.
6.2 Hydrochloric acid c(HCl) = 12 mol/l; 37 % volume fraction; ρ ≈ 1,18 g/ml.
6.3 Nitric acid c(HNO ) = 16 mol/l; not less than 65 % volume fraction, ρ ≈ 1,42 g/ml.
6.4 Mixed solution of 0,8 mol/l nitric acid and 1,8 mol/l hydrochloric acid
Mix 150 ml of hydrochloric acid (6.2) and 50 ml nitric acid (6.3) to 1,0 l of water (6.1).
6.5 Standard stock solution mercury standard stock solution, e.g. ρ = 1 000 mg/l.
Use suitable stock solutions. Single-element stock solutions with adequate specification stating the acid used
and the preparation technique are commercially available. It is recommended to use commercially available
standard stock solutions for mercury.
6.6 Working standard solutions
Depending on the scope, different working standard solutions may be necessary. In general, the stability of
mercury working standard solutions should be checked.
6.6.1 Working standard solution I ρ = 10 mg/l for mercury.
Dilute 1,00 ml of the standard stock solution for mercury (6.5) to 100,0 ml with the mixed acid solution (6.4).
This solution is used to prepare 200 µg/l mercury working standard solution.
6.6.2 Working standard solution II ρ = 200 µg/l for mercury.
Dilute 2,00 ml of the 10 mg/l mercury working standard solution I (6.6.1) to 100,0 ml with the mixed acid
solution (6.4). This solution is used to prepare spiked test solutions and calibration solutions.
6.7 Reducing agents
6.7.1 General
Tin(II) chloride or sodium borohydride may be used as the reducing agent, but it is not advisable to use the
two reagents alternately. Observe the instructions of the manufacturers of the apparatus. The concentration
by mass of the reducing agent solutions may be varied to suit the system, and the relevant information
provided by the manufacturer of the apparatus shall be observed.
6.7.2 Tin(II) chloride solution ρ(SnCl ·2H O) = 100 g/l.
2 2
Dissolve 50 g of tin(II) chloride in approximately 100 ml of hydrochloric acid (6.2) in a 500 ml volumetric flask
and dilute to the mark. Prepare a fresh solution daily.
6.7.3 Sodium borohydride solution e.g. ρ = 2 g/l.
Dissolve 2 g of sodium hydroxide pellets in water, add 2 g of sodium borohydride and dilute to 1 000 ml with
water (6.1). Prepare a fresh solution daily and, when necessary, filter before use. When the analysis
procedure is of a longer time it is recommended to cool the sodium borohydride solution (i.e. with ice around
the flask) during its use in the vapour generation ICP-AES or AAS measurement.
WARNING — It is essential to observe the safety instructions for working with sodium borohydride.
Sodium borohydride forms hydrogen with acids and this can result in an explosive air/hydrogen
mixture. A permanent extraction system shall be provided at the point where measurements are
carried out.
7 Apparatus
7.1 Common laboratory glassware
7.2 Analytical balance capable of weighing to an accuracy of 1 mg.
7.3 Inductively coupled plasma-atomic emission spectrometer with axial or radial viewing of the
plasma and with suitable background correction.
The settings of the working conditions (e.g. gas flows, RF or plasma power, sample uptake rate, integration
time, number of replicates) shall be optimised according the manufacturer’s instructions. Radial viewing of the
plasma may be used if it can be shown that the limit of quantification for mercury is below the required legal
limit value.
7.4 Atomic absorption spectrometer equipped with a heated quartz cuvette or a mercury absorption cell,
or optionally with an amalgamation system.
7.5 Vapour generation equipment
7.5.1 Continuous flow or flow-injection cold-vapour system
7.5.2 Element-specific lamp for mercury
7.6 Dilutor
Instrument used for automated volumetric dilutions or other appropriate equipment (e.g. pipettes and
volumetric glassware) to perform dilutions. The precision and accuracy of this type of equipment for volumetric
dilutions shall be established, and controlled and documented regularly.
7.7 Ash-free filter paper i.e. Whatman 589/2 or equivalent quality.
8 Procedure
8.1 General
Calibrations by standard additions with several standards or by matrix matching are very powerful calibration
techniques and can be used to accurately correct for matrix effects from easy-ionisable elements
(multiplicative matrix effects). Additive matrix effects (i.e. spectral interferences) are not corrected for with
standard additions calibration. For matrix matching, additive matrix effects will be corrected for when the
added matrix is the cause of the matrix effect. The main drawback of calibration by standard addition with
several standards is the requirement for a calibration function for each sample type, which is a time
consuming process. For matrix matching a profound knowledge of the sample matrix is needed, which is not
always necessarily available. These two techniques may thus not be practical to use in routine fertilizer
laboratories.
It is therefore suggested that calibrations are to be performed by means of external calibration and correction
of matrix effects by addition of one known spike of a standard solution (spike recovery). The method of
external calibration and correction for spike recovery allows for the analysis of fertilizers with unknown matrix
composition or with a matrix that cannot be synthetically imitated easily. This calibration technique may not be
as precise as calibration by standard additions with several standards but the increased uncertainty is small
compared to the total uncertainty of the method, if the total analyte concentration is in the linear working range
after the spike and the added spike corresponds to at least a doubling of the analyte concentration. Many
matrix errors can be compensated for by this procedure, if they are not additive (e.g. spectral interferences).
Aliquots of the sample solution are analysed by the means of external calibration and then one aliquot is
spiked with known concentrations of the analytes without changing the matrix of the sample solution.
...
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