1、RATIFIED EUROPEAN TEXT EN12396-i: 1998 European Standards only exist formally as national transpositions (Le. a BS EN for the UK) of a commonly agreed “ratified“ text. This document is a ratified text which will shortly be published as a BS EN. It is being made available in advance of its formal pub
2、lication to give interested parties early access to the technical infomation which the BS EN will contain. When the BS EN is formally published it will be supplied to you automatically, without any additional charge. Purchasers of this ratified text should be aware of the following limitations when
3、using the document. O The BS EN may contain additional information in the national foreword or national annex, O Full rights conferred by compliance with the standard may only be granted by reference to the formal national transposition of the text as a BS EN. This ratified text was approved by CENK
4、ENELEC in its three official languages on the date given below. Under CENCENELEC rules, BSI is obliged to publish its national transposition within six months of this date. This ratified text was approved on I 1998-10-02 1 NO COPYING WiTHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW STD-CE
5、N EN 1237b-L-ENGL 1778 3404589 01180742 910 = EUROPEANSTANDARD NORME EUROP (see figure 1). 5c 1 Liebig condenser 4 cylindrical flask or round bottomed flask 2 dropping funnel 5 absorption tubes 3 gas inlet tube 6 Widmer helix Figure 1 Decomposition and distillation apparatus STDOCEN EN 1234b-L-ENGL
6、3778 M 3404587 038071.17 4T2 W Page 6 EN 12396-1:1998 5.3 Flowmeter 5.4 Heating mantle, electrically operated, at least 450 W; or gas burner fitted with a Babo funnel and flask holder 5.5 Spe is the mass of the test portion (before the removal of any parts, e.g. stones), in grams. If the results ind
7、icate that the amount of residue approaches or exceeds the maximum residue limit, at least two further test portions shall be examined. N0TE:The routine limit of determination depends on the amount of test portion used. If the mass of the test portion is 200 g, the routine limit of determination lie
8、s at approximately 0,25 mg/kg. 1 O Confirmatory tests Analyses for confirmation using a different method should be performed, especially in those cases in which the result indicates that the maximum residue limit has been exceeded. NOTE 1 :The method specified in EN 12396-2:1998 permits carbon disul
9、fide to be identified from the retention time on a gas chromatography system and to be quantified. The results can be verified by coupled gas chromatography-mass spectrometry (GC-MS). NOTE 2 : The method in EN 12396-3 permits carbon disuttde to be determined spectrometrically as xanthogenate and is
10、especially useful for the determination of low levels of dithiocarbamate and thiuramdisulfide residues. NOTE 3:The results can also be confirmed by registering and comparing the absorption spectrum with a maximum at a wavelength of 435 nrn of the test sample with the spectnirn of carbon disulfide. S
11、TD-CEN EN L237b-L-ENGL 1778 340Li587 OLBO75L 923 Page 10 EN 12396-1:1998 NOTE 4: A method which determines undestroyed ethylene and propylene bisdithiocarbamates as their respective sodium salts by means of gel chromatographic separation and on line photometric determination at a wavelength of 285 n
12、m is described in SI. 11 Precision 11.1 General Details for the inter-laboratory test of the precision of the method are summatized in annex A. The values derived from the inter-laboratory test according to IS0 5725:1986 SI may not be applicable to anaiyte concentration ranges and matrices other tha
13、n given in annex A. 1 1.2 Repeatability The absolute difference between two single test results found on identical test material by one operator using the same apparatus within the shortest feasible time interval will exceed the repeatability limit rin not more than 5 YO of the cases. The values are
14、: apples: iu = 2,15 mgkg r= 0,49 mgkg witloof chicory: Si; = 0,242 mgkg r= 0,07 mg/kg 11.3 Reproducibility The absolute difference between two single test results on identical test material reported by two laboratories will exceed the reproducibility limit in not more than 5 % of the cases. .t The v
15、alues are: apples: X = 2,15mg/kg R= 0,79 mgkg witloof chicory: X = 0,242 mgkg R= 0,12 mg/kg 12 Test report The test report shall contain at least the following information: - all information necessary for the identification of the sample ; - a reference to this European Standard ; - the results and
16、the units in which they have been expressed ; - date and type of sampling procedure (if known) ; - date of receipt of sample in the laboratory ; - date of test ; - any particular points obsewed in the course of the test ; - any operations not specified in the method or regarded as optional which mig
17、ht have affected the results. - - STD.CEN EN L237b-L-ENGL 1778 I3404587 0380752 8bT Year of inter-laboratory test: number of samples: number of laboratories: Number of laboratories retained after elimination Page 11 EN 12396-1 1998 1993 1994 1 1 7 16 6 15 Annex A (informative) Number of accepted res
18、ults Mean value 5( mgkg Repeatability standard deviation mg/kg Repeatability relative standard deviation RSD, Repeatability limit f mg/kg Precision data 35 80 2,15 0,24 0,17 0,023 8,O % 9,7 Yo 0,49 0,066 In accordance with IS0 5725:1986 8, the following parameters have been defined in an inter- labo
19、ratory test. The test was conducted by the Arbeitsgruppe Pestizide“, Lebensmittelchemische Gesellschaft, division of the “Gesellschaft Deutscher Chemiker“, Frankfurt, Germany, l, m. Reproducibility reiative standard deviation RSDR Reproducibility limit R mgkg Horrat value H, For the inter-laboratory
20、 tests the tin(l1)-hydrochloric acid solution (4.1 1) was heated until boiling before it was added to the decomposition apparatus (5.2). To remove interfering substances, concentrated sulfuric acid (4.6) was used in the first adsorption tube prior to the sodium hydroxide solution (4.7) in the second
21、 tube. 13,O % 16,9 % 0,79 0,12 0,93 0.89 TaMe A.l Sample I Apple 1 Witloof chicory 1 - I Number of eliminated laboratories I 1-1 1 Reproducibility standard deviation a mg/kg 0,28 0,041 STD-CEN EN 1237b-1-ENGL 1798 3404589 0380753 7Tb D Page 12 EN 1 2396-1 : 1 998 Annex B (informative) Bibliography W
22、orking Group on Pesticides, Food and Forensic Chemistry Division of the Gesellschaft Deutscher Chemiker (Geman Chemical Society): Diaiiocarbamate and thiuram disuifide fungicides. In: Deutsche Forschungsgemeinschaft, Manual of Pesticide Residue Analysis, VCH Verlagsgesellschaft Weinheim, 1987, Vol.
23、1, pp 353 - 360 method S15. EEC document: 1729/11/80 - final 1. Cullen, T. E.: Spectrophotometric determination of dfthiocarbamate residues on food crops. AnaLChem., 1964,36,221-224. Keppel, G.E.: Modification of the carbon disulfide evolution method for dithiocarbamate residues. J. Assoc. Off. Anal
24、. Chem., 1969,52, 162-167. EEC Commission directive of 24.7.79 (79REEC) establishing community methods of sampling for the official control of pesticide residues in and on fruits and vegetables. Official Journal of the European Communities L 207, 15.8.1 979. Pflugmacher, J., and Ebing, W.: Ethylene
25、and propylene bisdithiocarbarnate fungicides. in: Deutsche Forschungsgemeinschaft, Manual of Pesticide Residue Analysis, VCH Verlagsgesellschaft Weinheim, 1987, Vol.1, pp. 407-412, method S 21. Gilsbach W.:Ringversuche der Arbeitsgruppe Pestizide zur Ermittlung von Przisionsdaten bei der Bestimmung von Dthiocarbamaten und Thiuramdisulfiden. Dtsch. Lebensm. Rdsch., 1996,92, pp. 351-353. IS0 5725:1986 Precision of test methods - Determination of repeatability and reproducibility for a standard test method by inter-laboratory tests
