BS EN 16109-2011 Fertilizers Determination of complexed micro-nutrient ions in fertilizers Identification of lignosulfonates《肥料 肥料中复合微量营养素离子的测定 木质素磺酸盐的识别》.pdf

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1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 16109:2011Fertilizers Determination ofcomplexed micro-nutrient ionsin fertilizers Identification oflignosulfonatesBS EN 16109:2011 BRITISH STANDARDNational forewordThis Bri

2、tish Standard is the UK implementation of EN 16109:2011.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 pur

3、port to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 70911 1ICS 65.080Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards

4、 Policy and Strategy Committee on 30 November 2011.Amendments issued since publicationDate Text affectedBS EN 16109:2011EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 16109 November 2011 ICS 65.080 English Version Fertilizers - Determination of complexed micro-nutrient ions in fertilizers - Id

5、entification of lignosulfonates Engrais - Dosage des oligo-lments complexs dans les engrais - Identification des lignosulfonates Dngemittel - Bestimmung der in Dngemitteln komplexgebundenen Spurennhrstoffionen - Identifizierung von Ligninsulfonaten This European Standard was approved by CEN on 1 Oct

6、ober 2011. 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 ob

7、tained 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

8、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, Luxembour

9、g, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights o

10、f exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 16109:2011: EBS EN 16109:2011EN 16109:2011 (E) 2 Contents Page Foreword 31 Scope 42 Normative references 43 Terms and definitions .44 Sampling and sample preparation .45 Method A: Determination of ph

11、enolic hydroxyl content and 232,5 nm absorption for the identification of lignosulfonates 46 Method B: Determination of organic sulfur content for the identification of lignosulfonates 87 Expression of the results . 118 Precision 129 Test report . 13Annex A (informative) Statistical results of the i

12、nter-laboratory test . 14A.1 General . 14A.2 Test Samples . 14A.3 Inter-laboratory test procedure . 14A.4 Results and statistical interpretation 14Bibliography . 17BS EN 16109:2011EN 16109:2011 (E) 3 Foreword This document (EN 16109:2011) has been prepared by Technical Committee CEN/TC 260 “Fertiliz

13、ers 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 2012, and conflicting national standards shall be withdrawn at the latest by

14、 May 2012. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. 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 respo

15、nsible for identifying any or all such patent rights. 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, Finla

16、nd, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 16109:2011EN 16109:2011 (E) 4 1 Scope This document specifies two compleme

17、ntary methods (method A and method B) that allow lignosulfonates to be indentified as soluble complexing agents in fertilizers. NOTE Lignosulfonate, as a complexing agent, is a natural polymer produced as a by-product of the sulfite method for manufacturing paper from wood pulp in the paper industry

18、. As a natural polymer, it presents a poorly defined and variable chemical structure. It is an intricate mixture of small- to moderate-sized polymeric compounds with sulfonate groups attached to the molecule, and diverse complexing capacity. The methods are applicable to EC fertilizers covered by Re

19、gulation (EC) No 2003/2003 1. 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) appli

20、es. 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: Ter

21、ms relating to fertilizers EN ISO 3696, Water for analytical laboratory use Specification and test methods (ISO 3696:1987) 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 Sampling and sample preparation Sampli

22、ng is not part 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. 5 Method A: Determination of phenolic hydroxyl content and 232,5 nm absorption for the identification of lignosulfonates

23、 5.1 Principle The method for the determination of the phenolic hydroxyl content is based on the ultraviolet absorption of phenols in alkaline solution (phenolate). The absorbance of an alkaline solution of the sample is measured directly against an acid solution of the same sample. The phenolic hyd

24、roxyl content of the sample is calculated from the molar extinction coefficient maximum of the resulting curve and the molar extinction coefficient of reference compounds determined in the same way. BS EN 16109:2011EN 16109:2011 (E) 5 The determination of the absorption at 232,5 nm is normally consi

25、dered the method for the quantification of lignosulfonates, providing that no other ultraviolet absorbing organic compounds are present. NOTE For additional information see 3 and 4. 5.2 Apparatus Usual laboratory equipment, glassware, and in particular the following: 5.2.1 Magnetic stirrer. 5.2.2 Ba

26、lance, capable of weighing to an accuracy of 1 mg. 5.2.3 Filter paper for qualitative analysis, pore size 15 m to 20 m.1 5.2.4 pH-meter, equipped with a glass electrode. 5.2.5 UV-Vis spectrophotometer, equipped with 1 cm quartz cells. 5.3 Reagents 5.3.1 General a) reagents shall be of recognized ana

27、lytical grade; b) water used for the preparation of sample solutions shall conform to EN ISO 3696, grade 2 and free of organic contaminants. 5.3.2 Hydrochloric acid solution, c(HCl)= 6 mol/l. 5.3.3 Sodium hydroxide solution, c(NaOH)= 0,1 mol/l. 5.3.4 Analytical grade fine mesh strong cation exchange

28、 resin 2Styrene/DVB type, 8 % crosslinked. Hydrogen form. Functional group: sulphonic acid. Nominal exchange capacity: 1,7 mmolc/ml. Mesh: 50 to 100. 5.4 Procedure 5.4.1 Preparation of stock solution Weigh, to the nearest 1 mg, 0,15 g to 0,20 g of the sample in a 100 ml beaker. Add 4 g of cation exc

29、hange resin (5.3.4) and about 20 ml to 25 ml of water. Allow the ion-exchange process to take place for 20 min, ensuring proper mixing by means of a magnetic stirrer. 1) Albet 412 filter paper or equivalent is an example of suitable product commercially available. This information is given for the c

30、onvenience of users of this European Standard and does not constitute an endorsement by CEN of this product. 2) Biorad AG 50 W-X8 (50-100) Cat. No. 142-1431 is an example of suitable product commercially available. This information is given for the convenience of users of this European Standard and

31、does not constitute an endorsement by CEN of this product. BS EN 16109:2011EN 16109:2011 (E) 6 Filter (5.2.3) into a 250 ml volumetric flask to remove the resin and thoroughly wash the filter. Dilute to the mark with water (stock solution). 5.4.2 Solution A (acid) Take an aliquot (40 5 ml) of the st

32、ock solution into a 100 ml beaker and adjust pH between 2,0 and 2,2 with few drops of hydrochloric acid solution (5.3.2). Pipette 5 ml of the pH-adjusted solution into a 50 ml volumetric flask and dilute to the mark. Final concentration 0,06 g/l to 0,08 g/l. 5.4.3 Solution B (basic) Pipette 5 ml of

33、the stock solution into a 50 ml volumetric flask. Add 10 ml of sodium hydroxide solution (5.3.3) to adjust pH over 11,0. Dilute to the mark. Final concentration 0,06 g/l to 0,08 g/l. Check that the pH of the solution is over 11,0, if not prepare solution B adding more sodium hydroxide. 5.4.4 Solutio

34、n C Pipette 10 ml of the stock solution into a 100 ml beaker and fill with water to 60 5 ml. Adjust the pH of the solution between 4,0 and 5,0 with the sodium hydroxide solution (5.3.3). Transfer quantitatively into a 100 ml volumetric flask, dilute to the mark with water and homogenize. See 5.4.6.

35、5.4.5 Measurement of phenolic hydroxyl content Fill both cells in the UV spectrophotometer with water. Enter background correction. Scan from 340 nm to 220 nm to check baseline. Fill the sample cell with solution B (5.4.3), and the reference cell with solution A (5.4.2). Scan from 340 nm to 220 nm.

36、Rinse cells with water. 5.4.6 Measurement of 232,5 nm absorption Fill the sample cell with solution C (5.4.4), and the reference cell with water and record absorbance at 232,5 nm. The absorbance of the final solution should be between 0,2 and 0,8 to minimize deviations from Beers Law instrumental er

37、ror. If necessary, the volume to be taken from stock solution (5.4.1) to prepare solution C (5.4.4) should be adapted. 5.5 Calculation 5.5.1 Phenolic hydroxyl content Plot the spectrum in terms of absorbance. Record wavelength and absorbance for the maximum peak at 240 nm to 260 nm and for the minim

38、um on either the right or the left side of the maximum. Subtract minimum absorbance from the maximum height (Absmax) (see Figure 1). BS EN 16109:2011EN 16109:2011 (E) 7 Figure 1 Example of the spectrum of solution B against A for the determination of phenolic hydroxyl content of a lignosulfonate sho

39、wing the maximum and the minimum (in this case at the left side) absorbances Calculate the phenolic hydroxyl content, wph, of the sample, expressed as mass fraction in percent using the Absmaxvalue of the sample and an average maxvalue for reference compounds (8 867,5 lmol-1cm-1) by the following fo

40、rmula: 1000100117 =maxmaxphdmAbsw (1) 525050 =d (2) where m is the mass of the test portion in grams; d is the dilution factor included in 5.4.1, 5.4.2. and 5.4.3, in millilitres; Absmaxis the value obtained subtracting the minimum from the maximum absorbance; 17 is the number of OH mol molOHgOH17;

41、maxis the average molar extraction coefficient for reference compounds (8 867,5 lmol-1cm-1). 5.5.2 232,5 nm absorption as lignosulfonic acid content Calculate the 232,5 nm absorption as lignosulfonic acid content, wla, of the sample, expressed as mass fraction in percent, by the following formula: 1

42、05,232la=fmdAw (3) BS EN 16109:2011EN 16109:2011 (E) 8 Vd250100 = (4) where A232,5is the absorbance recorded at 232,5 nm (5.4.6); m is the mass of the test portion in grams; d is the dilution factor in millilitres considering dilutions in 5.4.1 and 5.4.4; f is the absorptivity of the lignosulfonic a

43、cid in l/g cm, f = 36,5; V is the volume in millilitres used to prepare solution 5.4.4. 6 Method B: Determination of organic sulfur content for the identification of lignosulfonates 6.1 Principle Sulfur bound to the lignin backbone in lignosulfonate samples is commonly termed organic sulfur while th

44、e remaining sulfur is conveniently described as inorganic sulfur (free sulfur, bisulfite addition compounds, sulfates, sulfites, sulfides, thiosulfates and tetrathionates). The method is based on the oxidation of inorganic sulfur to sulfate with alkaline iodine and its determination as barium sulfat

45、e. The remaining compounds are oxidized with a nitric-perchloric acid mixture to destroy organic matter and convert the sulfonated sulfur to sulfate, which is then determined as barium sulfate. NOTE For additional information see 5. 6.2 Apparatus Usual laboratory equipment, glassware, and in particu

46、lar the following: 6.2.1 Magnetic stirrer. 6.2.2 Balance, capable of weighing to an accuracy of 0,1 mg. 6.2.3 Filter paper for qualitative analysis, pore size 15 m to 20 m.36.2.4 Ashless filter paper for quantitative analysis, pore size 2,5 m.46.2.5 Porcelain crucibles, resistant to 800 C. The cruci

47、bles shall be calcinated at 800 C before use. 6.2.6 pH-meter, equipped with a glass electrode. 3) Albet 412 filter paper or equivalent is an example of suitable product commercially available. This information is given for the convenience of users of this European Standard and does not constitute an

48、 endorsement by CEN of this product. 4) Whatman No. 42 filter paper or equivalent is an example of suitable product commercially available. This information is given for the convenience of users of this European Standard and does not constitute an endorsement by CEN of this product. BS EN 16109:2011

49、EN 16109:2011 (E) 9 6.2.7 Water bath or any other heating device. 6.2.8 Oven, (105 1) C. 6.2.9 Muffle furnace, 800 C. 6.3 Reagents 6.3.1 General a) reagents shall be of recognized analytical grade; b) water used for the preparation of sample solutions shall conform to EN ISO 3696, grade 2 and free of organic contaminants. 6.3.2 Sodium hydroxide solution, w(NaOH) = 10 %. 6.3.3 Hydrochloric acid, w 36 %-38 %. 6.3.4 Hydrochloric acid solution, c(HCl) about