1、BSI Standards PublicationBS EN 16320:2013Fertilizers Determinationof trace elements Determination of mercury byvapour generation (VG) afteraqua regia dissolutionBS EN 16320:2013 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 16320:2013. Itsupersedes PD CEN/TS 1
2、6320:2012 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee CII/37, Fertilisers and related chemicals.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the nec
3、essaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 81510 2ICS 65.080Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was pu
4、blished under the authority of theStandards Policy and Strategy Committee on 31 October 2013.Amendments issued since publicationDate Text affectedBS EN 16320:2013EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 16320 October 2013 ICS 65.080 Supersedes CEN/TS 16320:2012English Version Fertilizers
5、 - Determination of trace elements - Determination of mercury by vapour generation (VG) after aqua regia dissolutionEngrais - Dosage des lments traces - Dtermination du mercure par gnration de vapeur (VG) aprs digestion leau rgale Dngemittel - Bestimmung von Elementspuren - Bestimmung von Quecksilbe
6、r mit Verdampfungstechnik (VG) nach Knigswasseraufschluss This European Standard was approved by CEN on 29 August 2013. 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
7、 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 lan
8、guage 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, Denma
9、rk, 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
10、FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2013 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 16320:2013: EBS EN 16320:2013EN 16320:2013
11、(E) 2 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 . 5 8 Procedure . 6 8.1 General . 6 8.2 Preparation of the test solution . 7 8.2.1 General . 7 8.2.2 Preparation . 7 8.3 Prepar
12、ation of the test solution for the correction of matrix effects by spike recovery . 7 8.4 Preparation of the blank test solution . 8 8.5 Preparation of the calibration solutions 8 8.5.1 Calibration solutions for the analysis of mercury 8 8.5.2 Calibration standards. 8 8.6 Determination of mercury 8
13、8.6.1 General . 8 8.6.2 Determination by VG-AAS . 8 8.6.3 Spectrometer settings of VG-AAS . 9 8.6.4 Determination by VG-ICP-AES . 9 9 Calculation and expression of the results 10 9.1 External calibration 10 9.2 Correction for spike recovery 10 9.3 Standard addition method . 11 9.4 Calculation of the
14、 element content in the sample 12 10 Precision . 12 10.1 Inter laboratory tests 12 10.2 Repeatability . 12 10.3 Reproducibility . 12 11 Test report 13 Annex A (informative) Results of the inter-laboratory test 14 Bibliography 15 BS EN 16320:2013EN 16320:2013 (E) 3 Foreword This document (EN 16320:20
15、13) has been prepared by Technical Committee CEN/TC 260 “Fertilizers and liming materials”, 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 April 2014, and
16、 conflicting national standards shall be withdrawn at the latest by April 2014. 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 d
17、ocument supersedes CEN/TS 16320:2012. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. The following changes have been made to the former edition: a) the CEN Technical Specification has been adopted as a European Standar
18、d; b) the document has been editorially revised. According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, F
19、ormer 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. BS EN 16320:2013EN 16320:2013 (E) 4 1
20、Scope This European Standard 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 spectro
21、meter. 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,
22、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 12944-2:19
23、99, 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
24、: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 i
25、nductively coupled plasma-atomic emission spectrometer (ICP-AES). 5 Sampling and sample preparation Sampling is not part of the methods specified in this European Standard. A recommended sampling method is given in EN 1482-1. Sample preparation shall be carried out in accordance with EN 1482-2. 6 Re
26、agents Use only reagents of recognised 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
27、 Water, conforming to grade 2 of EN ISO 3696. 6.2 Hydrochloric acid, c(HCl) = 12 mol/l; 37 % volume fraction; 1,18 g/ml. 6.3 Nitric acid, c(HNO3) = 16 mol/l; not less than 65 % volume fraction, 1,42 g/ml. BS EN 16320:2013EN 16320:2013 (E) 5 6.4 Mixed acid solution of 0,8 mol/l nitric acid and 1,8 mo
28、l/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. = 1 000 mg/l. Use suitable stock solutions. Single-element stock solutions with adequate specification stating the acid
29、 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 wo
30、rking standard solutions should be checked. 6.6.1 Working standard solution I, = 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 g/l mercury working standard solution. 6.6.2 Work
31、ing standard solution II, = 200 g/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) chl
32、oride 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 inf
33、ormation provided by the manufacturer of the apparatus shall be observed. 6.7.2 Tin(II) chloride solution, (SnCl22H2O) = 100 g/l. 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.
34、6.7.3 Sodium borohydride solution, e.g. = 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 rec
35、ommended 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
36、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. BS EN 16320:2013EN 16320:2013 (E) 6 7.3 I
37、nductively 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 accor
38、ding the manufacturers 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
39、 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)
40、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 589/21)or equivalent quality. 8 Procedure 8.1 General Calibrations by standard additions with sev
41、eral 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 cal
42、ibration. 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 consu
43、ming 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 ext
44、ernal 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 easil
45、y imitated synthetically. 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 s
46、pike 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 on
47、e aliquot is spiked with known concentrations of the analytes without changing the matrix of the sample solution. The calculated spike recovery is then used to correct the concentration calculated from the external calibration function. The concentration of the spikes shall be in the linear working
48、range of the analytical detection technique used. 1) Whatman 589/2is an example of a suitable product available commercially. This Information is given for the convenience of users of this European Standard and does not constitute an endorsement by CEN of this product. Equivalent products may be use
49、d if they can be shown to lead to the same results. BS EN 16320:2013EN 16320:2013 (E) 7 8.2 Preparation of the test solution 8.2.1 General The following extraction procedure leads, in most cases for mineral fertilizers, to trace element results which correspond to the total contents of these elements. Calibration with several standard additions and external calibration after matrix matching may also be used without any problems. 8.2.2 Preparation 8.2.2.1 Weigh (3 0,003) g of the prepared sample and transfer to a suitable reacti
