1、STDaBSI BS EN 13342-ENGL 2000 E ltb24bb9 0875751 T1 BRITISH STANDARD Characterization of sludges - Determination of Kjeldahl nitrogen The European Standard EN 13342:2 has the status of a British Standard ICs 13.030.20 NO COPYZNG WiXOuT BSI PERMISSION EXCEPT AS PERMITIED BY COPYRIGHT LAW m BS EN 1334
2、2:ZOOO STD*BSI BS EN 13342-ENGL 2000 W Lb24bb9 0875752 951 W BS EN 13342:2 Committee and comes into effect on 16 October Zoo0 AmdNo. Q BSI lCL2O National foreword Date Comments This British Standard is the official English language version of EN 13342:2000. The UK participation in its preparation wa
3、s entrusted to Technical Committee EW5, Sludge characterization, which has the responsibility to: - aid enquirem to understand the text; - present to the responsible European committee any enquiries on the - monitor related international and European developments and promulgate A list of organizatio
4、ns represented on this committee can be obtained on request to its secretary. Further information Users of this standard are informed that the UK submitted some substantial comments at the finai voting stage of the drafi EN for the following reasons. 1) In annex A, it is essential that the descripti
5、on of the four samples used in the inter-laboratory comparison is given. This can be achieved by the addition of a simple footnote. It is recommended that this topic is discussed at the TC308 meeting in Urecht. A documented minimum requirement for inter-laboratory comparisons is needed 2) The follow
6、ing note should be added to the scope: “The validation for this standard has oniy been carried out using materials as described in annex A. For other sludges, the user should validate the method using recovery and reproducibility tests”. 3) The date that the Moratory inter-comparison was carried out
7、 should be also given 4) The final phrase “and sludge products”, in the first sentence of the scope should be removed as it is inappropriate. 5) In 6.1, suggest replacing the first sentence, “The igestion fails to determine nitrogen in the form ”, with The digestion may fail to fully recover nikogen
8、 in the form of ”. Also suggest that a cross-reference to the UK Blue Book method be made. This has a useful introductory historical section (Al) on recoveries of “difficult” nitrogen species using the yjeldahi method. yjeldahi Nirogen in Waters 1987, HMSO 1988, ISBN O 11 752129 91 6) In annex A: in
9、terpretation, or proposals for change, and keep the UK interests informed; them in the UK. (i) CVR, in column 6, should be CVr in all three language versions: (i) all of the English and German coefficients of variation of both reproducibility (CVd and repeatability (CYr) are wrongly caldated. The du
10、es are wrong by up to a factor three, which is to high. ISBN O 580 36290 6 STD-BSI BS EN l13342-ENCL 2000 Lb246b9 0875753 898 = BS EN 13342:2 7) In the section on Analyticai or Glass digestion tubes, 250 ml capacity for use with a temperature controlled heating block. 7.2 Heating device Kjeldahl fla
11、sks can be heated singly or more usually, in a rack carrying several vessels, by use of either a Bunsen burner or electric heating mantle. It is important, however, that the glass surface above the digestion mixture receives no direct heating. Heating blocks capable of maintaining a temperature suff
12、icient to reflux the digestion mixture are commercially available. These hold typically up to 24 digestion tubes allowing for high laboratory throughput. 7.3 Distillation apparatus The digestion vessel should be suitable for direct attachment to glass apparatus incorporating an anti-splash distillat
13、ion head, a vertical water condenser and a delivery tube, the outlet of which is submerged in the absorbent solution. Commercial automatic Kjeldahl steam distillation apparatus is suitable for this determination. 7.4 Boiling aids Anti-bumping granules or glass beads. 8 Sample pretreatment Drying of
14、sludge will tend to deplete free ammonia and, depending on the pH, ammonium salts. For this reason, a test portion of a wet homogenized sample shall be used (see EN IS0 5667-1 3). Q BSI 10-2000 Page 8 EN 13342:2000 9 Procedure 9.1 digestion vessel (7.1). Transfer a known mass of homogenized, wet slu
15、dge (equivalent to 0,25 g to 0,5 g of dry mass) to a A blank shall be run by substituting 5 ml of water instead of the wet sludge with each batch of samples. NOTE For paste-like sludges, nitrogen-free paper can be used for sample transfer to the digestion vessel (7.1). 9.2 aids (7.4). Add (5,O f 0,l
16、) g of catalyst mixture (6.2) (or equivalent commercial tablets) and 2 or 3 anti-bumping 9.3 Cautiously add (10 f 0,5) ml of sulphuric acid (6.1), gently swirling the vessel. 9.4 while any foaming subsides. Heat the vessel slowly in an extracted area (e.g. fume cupboard) to drive off the water prese
17、nt and 9.5 half way along the neck of the vessel. White fumes of sulphur trioxide should be visible above the liquid. Heat the vessel more strongly to maintain a brisk boiling. The sulphuric acid should reflux up to about NOTE If commercial digestion equipment is used, the manufacturers instructions
18、 should be followed. 9.6 for at least a further 60 min. The contents of the vessel should eventually become clear or straw coloured. Continue the digestion 9.7 order to avoid crystallization of the digest. Allow the digest to cool and cautiously add (40 f 5) ml of water whilst gently swirling the ve
19、ssel in 9.8 If the digestion vessel (7.1) is suitable for direct attachment to the distillation apparatus, make up to approximately two thirds of its volume with water. If not, transfer the digest quantitatively to a Kjeldahl distillation flask adapted to the distillation (7.3) and make up to approx
20、imately two thirds of its volume with water (6.5). 9.9 acid (6.4.3) to the receiver flask, and ensure that the delivery tube is below the acid surface. Assemble the distillation apparatus adding 50 ml of 0,05 mol/l sulphuric acid (6.4.2) or 50 ml of boric 9.10 Cautiously add (30 f 2) ml of sodium hy
21、droxide solution (6.3) down the side of the distillation flask leading to two distinct layers. Assemble the apparatus and swirl the flask carefully to mix the contents without losing any liberated ammonia. NOTE instructions should be followed. This step may not be necessary for commercial automatic
22、distillation apparatus; the manufacturers 9.11 Heat the flask so that distillation proceeds at about 10 ml/min. NOTE For commercial systems, the manufacturers instructions should be followed. 9.12 Collect about 120 ml of distillate then lower the receiver so that the delivery tube is above the acid
23、surface, and collect a further 30 ml of distillate. NOTE For commercial systems, the manufacturers instructions should be followed. 9.13 Stop the distillation and wash the delivery tube into the receiving flask with about 5 ml of water. 9.14 If necessary, dilute the distillate to a known volume with
24、 water and mix well. NOTE For the titrimetric endpoint, the whole distillate can be titrated with acid. See clause 10. 9.15 Use the solution from 9.14 to determine the ammonia-nitrogen content of the made-up distillate in accordance with IS0 5664 or EN 25663. O BSI 10-2000 STD.BS1 BS EN L334Z-ENGL 2
25、000 H Lb24bb 08757b2 BTO Page 9 EN 13342:2000 NOTE Tryptophan (C11H12N202) or glycine (C2HsN02) can be used for checking the method efficiency. Ammonium sulphate (NHaS04) can be used for checking the distillation efficiency. These three substances should be dried at 105C for at least two hours prior
26、 to use. 10 Expression of results 10.1 Calculation 10.1.1 Colorimetric determination The Kjeldahl nitrogen content (N) is expressed in grams per kilogram dry mass and is given by equation (1): (C- B)x V N= mx 10 x WDR where C is the ammonia-nitrogen content of the made-up distillate, in milligrams p
27、er litre (9.15); B m V is the result for the blank determination (9.1) of the made-up distillate, in milligrams per litre; is the wet mass of sample taken for digest, in grams; is the final volume of distillate, in millilitres; WDR is the dry residue of the sludge determined in accordance with EN 12
28、880, in percent. 10.1.2 Titrimetric determination The Kjeldahl nitrogen content (N) is expressed in grams per kilogram dry mass and is given for titration of the whole distillate by equation (2): XI00 (Vi - V)X c x 14,Ol N= WDR where c VI v2 is the concentration of hydrochlorid acid in moles per lit
29、re; is the titration volume, in millilitres; is the titration volume of the blank sample, in millilitre; m WDR is the wet mass of sample taken for digest in grams; is the dry residue content of the sludge determined in accordance with EN 12880, in percent; 14,Ol is the atomic mass of nitrogen. 10.2
30、Precision data See annex A. Q BSI 10-2000 STD-BSI BS EN 13342-ENGL 2000 Lb2YbbS 0875763 737 Page 10 EN 13342:2000 I1 Test report The test report shall contain the following information: a) reference to this European Standard: b) all information necessary for complete identification of the sludge sam
31、ple; c) details of sample pre-treatment, if carried out; d) results of the determination according to clause IO; e) any detail not specified in this European Standard and any other factor which may have affected the results. O BSI 10-2000 STD=BSI BS EN 13342-ENGL 2000 1b24bb9 08757b4 b73 Page 11 EN
32、13342:2000 Annex A (informative) Performance data of interlaboratory comparison The below data were determined within the frame of a joint interlaboratory comparison for the parameters “loss on ignition of dry mass“ (EN 12879), “dry residue and water content“ (EN 12880) and pH-value (EN 12176) and f
33、or this standard “Kjeldahl nitrogen“. Table A.l - Precision data for Kjeldahl nitrogen I is the number of laboratories; n is the number of values; NAP is the percentage of outliers; x is the overall mean; UR is the standard deviation of reproducibility; VcRis the coefficient of variation of reproduc
34、ibility; or is the standard deviation of repeatability; VC, is the coefficient of variation repeatability; mdr is the dry mass. - Q BSI 10-2000 STD-BSI BS EN L3342-ENGL 2000 = Lb24bb9 08151bS SOT W BS EN 13342:2000 BSI 389 Chiswick High Road London w4 4AL BSI - British Standards Institution BSI is t
35、he independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the intemationai level. It is incorporated by Royal Charter. Revisions British Stan- are updated by amendment or revision Users of British Standards should make sure that t
36、hey possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technicai committee responsible, the
37、 identity of which can be found on the inside front cover. Tel: 020 8996 9OOO. Fax: 020 8996 7400. BSI offers members an individual updating service cailed PLUS which ensures that subscribes automatically receive the latest editions of stanhds. Buying standards Orders for all BSI, intemational and f
38、oreign standards publications should be addressed to Customer Services. Tel: 020 8996 9001. Fax: 020 8996 7001. In response to orders for international standards, it is BSI policy to supply the BSI implementation of thme that have been published as British Standards, unless otherwise requested. Info
39、rmation on standards BSI provides a wide range of information on national, European and international standards through its Library and its Technid Help to Exporters Service. Various BSI electronic infomation services are also available which give details on ail its products and services. Contact th
40、e Infomation Centre. Tel 020 8996 7111. Fax: 020 8996 7048. Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards. For detaiis of these and other benefits contact Membership Administrati on Tel 020 8996 7002. F
41、ax: 020 8996 7001. Copyright Copyright subsists in all BSI publications. BSI also holds the copyright, in the UK, of the publications of the international standardization bodies. Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval
42、 system or transmitted in any form or by any means - electronic, photocopying, recording or otherwise - without prior written permission from BSI. This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designatio
43、ns. If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained. If permission is granted, the terms may include royalty payments or a licensing agreement. Details and advice can be obtained from the Copyright Manager. Tel 020 8996 7070.
