1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 16195:2012Fertilizers Determination of chlorides in the absence of organic materialBS EN 16195:2012 BRITISH STANDARDNational forewordThis British Standard is the UK impleme
2、ntation of EN 16195:2012. It supersedes DD CEN/TS 16195:2011, which is withdrawn.The UK participation in its preparation was entrusted to T e c h n i c a l C o m m i t t e e C I I / 3 7 , F e r t i l i s e r s a n d r e l a t e d c h e m i c a l s .A list of organizations represented on this committ
3、ee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2012. Published by BSI Standards Limited 2012.ISBN 978 0 580 78188 9 ICS 65.080
4、 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 December 2012.Amendments issued since publicationDate T e x t a f f e c t e dBS EN 16195:2012EUROPEAN STANDAR
5、D NORME EUROPENNE EUROPISCHE NORM EN 16195 November 2012 ICS 65.080 Supersedes CEN/TS 16195:2011English Version Fertilizers - Determination of chlorides in the absence of organic material Engrais - Dosage des chlorures en labsence de matires organiques Dngemittel - Bestimmung von Chlorid bei Abwesen
6、heit organischer Stoffe This European Standard was approved by CEN on 6 October 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
7、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 th
8、e 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 Yugos
9、lav 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 COMIT EUROPEN
10、DE NORMALISATION EUROPISCHES KOMITEE FR 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 16195:2012: EBS EN 16195:2012EN 16195:2012 (E) 2 Contents Page Foreword 31 Sc
11、ope 42 Normative references 43 Terms and definitions .44 Principle 45 Sampling .46 Reagents .47 Apparatus .58 Procedure .58.1 Preparation of the test portion and the solution 58.2 Determination .58.3 Blank test 68.4 Control test .69 Calculation and expression of the results 610 Precision .610.1 Inte
12、r-laboratory test .610.2 Repeatability .610.3 Reproducibility .611 Test report 7Annex A (informative) Statistical results of the inter-laboratory test 8Bibliography 9BS EN 16195:2012EN 16195:2012 (E) 3 Foreword This document (EN 16195:2012) has been prepared by Technical Committee CEN/TC 260 “Fertil
13、izers 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 May 2013, and conflicting national standards shall be withdrawn at the latest
14、by May 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 supersedes CEN/TS 16195:2011. The following changes have be
15、en made to the former edition: a) the CEN Technical Specification has been adopted as a European Standard; b) the document has been editorially revised. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. According to the C
16、EN/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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hung
17、ary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 16195:2012EN 16195:2012 (E) 4 1 Scope This European Standard specifies a method for the determinati
18、on of chlorides in the absence of organic material. The method is applicable to all fertilizers which are free from organic material. 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
19、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 materia
20、ls 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 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 12944 1:1999 and EN 12944-2:19
21、99 apply. 4 Principle The chlorides, dissolved in water, are precipitated in an acid medium by an excess of standard solution of silver nitrate. The excess is titrated with a solution of ammonium thiocyanate in the presence of ferric ammonium sulfate (Volhards method). 5 Sampling Sampling is not par
22、t of the method specified in this document. A recommended sampling method is given in EN 1482-1. Sample preparation shall be carried out in accordance with EN 1482-2. Grinding of the laboratory sample is recommended for homogeneity reasons. 6 Reagents Use only reagents of recognised analytical grade
23、. 6.1 Water, distilled or demineralised and free from chlorides. 6.2 Nitrobenzene or diethyl ether. 6.3 Nitric acid, c = 10 mol/l. 6.4 Indicator solution. Dissolve 40 g of ferric ammonium sulfate Fe2(SO4)3. (NH4)2SO4. 24H2O, in water and make up to 1 l. BS EN 16195:2012EN 16195:2012 (E) 5 6.5 Silver
24、 nitrate standard solution, c = 0,1 mol/l. Preparation: since this salt is hygroscopic and cannot be dried without risk of decomposition, it is advisable to weigh out an amount of approximately 18 g, dissolve in water and make up the volume to 1 l. Adjust to c = 0,1 mol/l substance concentration by
25、titration of ammonium thiocyanate 0,1 mol/l. Silver nitrate standard solution is also readily available commercially and may be used instead. 6.6 Ammonium thiocyanate, standard solution, c = 0,1 mol/l. Preparation: since ammonium thiocyanate is hygroscopic and cannot be dried without risk of decompo
26、sition, it is advisable to weigh out an amount of approximately 9 g, dissolve in water and make up the volume to 1 l. Adjust to c = 0,1 mol/l substance concentration by titration of silver nitrate 0,1 mol/l. Ammonium thiocyanate standard solution is also readily available commercially, and may be us
27、ed instead. 7 Apparatus 7.1 Standard laboratory equipment. 7.2 Rotary shaker, 35 to 40 min-1. 7.3 Burettes. 7.4 Graduated flask, capacity 500 ml and 1 000 ml. 7.5 Conical (Erlenmeyer) flask, capacity 250 ml. 8 Procedure 8.1 Preparation of the test portion and the solution Place 5 g of the laboratory
28、 sample, weighed to the nearest 0,001 g, in a graduated flask (7.4) and add 450 ml of water (6.1). Mix for 0,5 h on the shaker (7.2), make up to 500 ml with water (6.1), mix and filter into a beaker. 8.2 Determination Take an aliquot part of the test solution containing not more than 0,150 g of chlo
29、ride: for example 25 ml (0,25 g), 50 ml (0,5 g) or 100 ml (1 g). If the amount of the test solution taken is smaller than 50 ml it is necessary to make up the volume to 50 ml with water (6.1). Add 5 ml of nitric acid (6.3), 20 ml of the indicator solution (6.4), and two drops of ammonium thiocyanate
30、 standard solution (6.6) (this latter reagent is added with a burette adjusted to zero for this purpose). With a burette (7.3) then add silver nitrate standard solution (6.5) until there is an excess of 2 ml to 5 ml. Add 5 ml of nitrobenzene or 5 ml of diethyl ether (6.2) and shake well to agglomera
31、te the precipitate. Titrate the excess silver nitrate with ammonium thiocyanate (6.6) until a red-brown colour appears which remains after the flask has been shaken slightly. NOTE Nitrobenzene or diethyl ether (but above all nitrobenzene) prevents the silver chloride from reacting with thiocyanate i
32、ons. Thus a clear colour change is obtained. BS EN 16195:2012EN 16195:2012 (E) 6 8.3 Blank test Carry out a blank test (omitting the test portion) under the same conditions and allow for it when calculating the final result. 8.4 Control test Before carrying out the estimations check the accuracy of
33、the method by using an aliquot part of a freshly prepared solution of potassium chloride, such that this part contains a known quantity in the order of 100 mg of chloride. 9 Calculation and expression of the results Express the result of the analysis as a percentage of chloride contained in the samp
34、le as it has been received for analysis. Calculate the mass fraction of chlorides (Cl), wCl, in percent according to Formula (1). 100)()(5460,003caaCZZCl=MVVVVw (1) where Vz is the amount of silver nitrate 0,1 mol/l, in millilitres; Vcz is the amount of silver nitrate 0,1 mol/l, used in the blank te
35、st, in millilitres; Va is the amount of ammonium thiocyanate 0,1 mol/l, in millilitres; Vca is the amount of ammonium thiocyanate 0,1 mol/l, used in the blank test, in millilitres; M is the mass, in grams, of the test portion taken (8.1). 10 Precision 10.1 Inter-laboratory test An inter-laboratory t
36、est has been carried out in 2009 with 14/13 participating laboratories and two different samples. The repeatability and reproducibility were calculated according to ISO 5725-2. The values derived from these inter-laboratory tests may not be applicable to concentration ranges and matrices other than
37、those given in Annex A. 10.2 Repeatability The absolute difference between two independent single test results, obtained with the same method on identical test material in the same laboratory by the same operator using the same equipment within a short interval of time, will in not more than 5 % of
38、the cases exceed the values of r given in Table 1. 10.3 Reproducibility The absolute difference between two single test results, obtained with the same method on identical test material in different laboratories by different operators using different equipment, will not exceed values of R given in T
39、able 1 in more than 5 % of the cases. BS EN 16195:2012EN 16195:2012 (E) 7 Table 1 Mean values, repeatability and reproducibility limits Sample x % r % R % Patent kali 2,781 0,066 0,284 NPK2 (12-11-18+4+8) 0,478 0,076 0,312 11 Test report The test report shall contain at least the following informati
40、on: a) all information necessary for the complete identification of the sample; b) the test method used with reference to this document; c) the test results obtained; d) date of sampling and sampling procedure (if known); e) date when the analysis was finished; f) whether the requirement of the repe
41、atability limit has been fulfilled; g) all operating details not specified in this document, or regarded as optional, together with details of any incidents occurred when performing the method, which might have influenced the test result(s). BS EN 16195:2012EN 16195:2012 (E) 8 Annex A (informative)
42、Statistical results of the inter-laboratory test The precision of the method was established in 2009 by Working Group 7 “Chemical analysis” of CEN/TC 260 “Fertilizers and liming materials” in an inter-laboratory test evaluated in accordance with ISO 5725-2. The statistical results are given in Table
43、 A.1. Table A.1 Statistical results of the inter-laboratory test Parameter Sample Patent kali NPK2 (12-11-18+4+8) Number of participating laboratories 14 13 Number of laboratories after elimination of outliers (accepted test results) 11 13Mean value x (%) 2,781 0,478 Repeatability standard deviation
44、 sr(%) 0,024 0,027RSDr(%) 0,9 6,0 Repeatability limit r (%) 0,066 0,076Reproducibility standard deviation sR(%) 0,101 0,111 RSDR(%) 3,6 23,0Reproducibility limit R (%) 0,284 0,312 BS EN 16195:2012EN 16195:2012 (E) 9 Bibliography 1 EN 1482-1, Fertilizers and liming materials Sampling and sample prepa
45、ration Part 1: Sampling 2 ISO 5725-2, Accuracy (trueness and precision) of measurement methods and results Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method 3 Regulation (EC) No 2003/2003 of the European Parliament and of the Council of
46、13 October 2003 relating to fertilisers, Official Journal L 304, 21/11/2003, p. 0001-0194, Annex I and Annex IV, method 6.1 This page deliberately left blankThis page deliberately left blankBSI is the independent national body responsible for preparing British Standards and other standards-related p
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