1、 ISO 2012 Medical gloves made from natural rubber latex Determination of water-extractable protein using the modified Lowry method AMENDMENT 1 Gants mdicaux base de latex de caoutchouc naturel Dtermination des protines extractibles par leau par la mthode modifie de Lowry AMENDEMENT 1 INTERNATIONAL S
2、TANDARD ISO 12243 First edition 2003-10-01 Reference number ISO 12243:2003/Amd.1:2012(E) AMENDMENT 1 2012-12-15 ISO 12243:2003/Amd.1:2012(E) ii ISO 2012 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2012 All rights reserved. Unless otherwise specified, no part of this publication may be repro
3、duced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 7
4、49 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ISO 12243:2003/Amd.1:2012(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing Internation
5、al Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO,
6、 also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical comm
7、ittees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the p
8、ossibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Amendment 1 to ISO 12243:2003 was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee SC 3, Raw
9、materials (including latex) for use in the rubber industry. ISO 2012 All rights reserved iii Medical gloves made from natural rubber latex Determination of water-extractable protein using the modified Lowry method AMENDMENT 1 Page 1, Normative references Delete Clause 2 and move the normative refere
10、nces to the Bibliography. Renumber the subsequent clauses. Renumber all cross-references to subclauses of Clauses 5, 6, 7 and 8, beginning with 7.2.1, i.e. replace “Use protein-free gloves (5.1) to handle .” with “Use protein-free gloves (6.1) to handle .”. Page 3, Clause 5 Following 5.11, add the f
11、ollowing new paragraph: “5.12 Shaker”. Page 3, 6.3.2 Replace the note with the following new note.NOTE 2 N Folin reagent is available commercially. The concentration of some commercial Folin reagents might not be 2 N. Page 4, 6.4 Replace the first paragraph with the following: “Use ovalbumin prepare
12、d by ammonium sulfate fractionation and repeated crystallization at pH 4,5.”. Page 4, 7.2.1 Replace the first paragraph with the following (adding a sentence to clarify why there are two extraction procedures).The entire surface of the glove shall be exposed to the extractant at 25 C 5 C for a perio
13、d of 120 min 5 min. Two extraction procedures are permitted, the so-called “cut-glove” procedure and also the “glove-in- glove” procedure. In case of dispute, the “cut-glove” procedure is preferred as it is more practicable and less time consuming. In the case of the “glove-in-glove” procedure, if p
14、in holes exist, discard the sample and repeat the extraction with a fresh pair of gloves. The procedure used shall be noted in the test report and all samples in a given series shall be extracted by the same procedure. The extraction shall be carried out in triplicate and single determinations run o
15、n each extract. ISO 12243:2003/Amd.1:2012(E) ISO 2012 All rights reserved 1 ISO 12243:2003/Amd.1:2012(E) Page 5, 7.2.2.3 Replace the second paragraph with the following.Cut a rectangular piece from the back of the glove of about 0,5 dm by 0,5 dm and measure its dimensions to the nearest 0,01 dm. Cal
16、culate the area A 1 . Page 5, 7.2.2.6 Replace the paragraph with the following.Extract the test sample at 25 C 5 C for 120 min 5 min, shaking for 15 s initially and thereafter at intervals not greater than 30 min. If practicable, continuous slow shaking at approximately 200 r/min is desirable. Page
17、5, 7.2.3.3 Replace the first sentence with the following: “Fix the gloves to a shaker and shake at approximately 200 r/min for 120 min 5 min at 25 C 5 C.”. Page 5, 7.2.3.5 Replace the paragraph with the following (in order to harmonize the text with 7.2.2.7).Decant the extract from the outer glove i
18、nto a centrifuge tube (5.3). If it is coloured blue, it is indicative of a pin-hole or cross-contamination. In such cases, discard the solution and repeat the extraction with a fresh pair of gloves. Clarify the extract by centrifugation at not less than 20 000 m/s 2(2 000 g) for 15 min. The extract
19、is preferably used immediately but may be stored for up to 48 h at a temperature of not more than 7 C or frozen for up to 15 days at below 10 C. Page 5, 7.2.3.6 Add the following new paragraph 7.2.3.7 If the result is to be reported in micrograms per unit area of the glove (e.g. g/dm 2 ), follow 7.2
20、.2.3. Pages 8 to 9, Clause 9 Transfer the contents of Clause 9 to the following new informative Annex E. Replace the text of the clause with: “See Annex E.”. 2 ISO 2012 All rights reserved ISO 12243:2003/Amd.1:2012(E) Annex E (informative) Precision E.1 Background An interlaboratory test programme (
21、ITP) to evaluate the precision of the method was conducted in 2002 using the precision procedures and guidelines described in ISO/TR 9272:1986. Both extraction procedures were evaluated: the cut-glove procedure and the glove-in-glove procedure. The ITP was conducted with four materials with increasi
22、ng measurement levels. Seven laboratories participated in the ITP, and a type 1 precision was evaluated. A test result is the mean of three replicates on each of two separate test days, and precision is given in terms of test results, i.e. a mean value for each of two test days. The precision result
23、s as determined by this ITP shall not be applied to acceptance or rejection testing for any group of materials or products without documentation that the results of this precision evaluation actually apply to the products or materials tested. E.2 Precision results E.2.1 General For each of the four
24、materials, the precision results for both procedures are given in Table E.1. These results were obtained using the outlier replacement procedures and outlier deletion procedures as described in ISO/TR 9272:1986. General statements for the use of the precision results are cited below. These are given
25、 in terms of both the absolute precision, r and R, and also for the relative precision, (r) and (R). See additional comments below. E.2.2 Repeatability The repeatability, or local-domain precision, for each of these procedures has been established by the values found in Table E.1, for each measureme
26、nt level (for the materials) as listed in the table. Two single mean test results (obtained by the proper use of this International Standard) that differ by more than the tabulated values for r, in measurement units, and (r), in percent, shall be considered suspect, i.e. to have come from different
27、populations. Such a decision suggests that some appropriate investigative action be taken. E.2.3 Reproducibility The reproducibility, or global-domain precision, for each of these procedures has been established by the values found in Table E.1, for each measurement level (for the materials) as list
28、ed in the table. Two single mean test results obtained in different laboratories (by the proper use of this International Standard) that differ by more than the tabulated values for R, in measurement units, and (R), in percent, shall be considered suspect, i.e. to have come from different population
29、s. Such a decision suggests that some appropriate investigative action be taken. ISO 2012 All rights reserved 3 ISO 12243:2003/Amd.1:2012(E) Table E.1 Precision data Cut-glove procedure (procedure A) Material Mean value g/g Within laboratory Between laboratories Number of laboratories s r r (r) s R
30、R (R) 1 14,3 3,48 9,7 68,3 7,57 21,2 148,5 5 2 68,3 6,46 18,1 26,5 12,6 35,2 51,5 5 3 162,2 6,79 19,0 11,7 25,1 70,3 43,3 5 4 200,6 13,6 37,9 18,9 28,2 78,9 39,3 5 Glove-in-glove procedure (procedure B) Material Mean value g/g Within laboratory Between laboratories Number of laboratories s r r (r) s
31、 R R (R) 1 13,8 1,66 4,64 33,6 4,70 13,2 95,2 6 2 53,1 4,97 13,93 26,3 16,3 45,6 86,0 6 3 140,0 5,25 14,70 10,5 21,7 60,9 43,5 6 4 164,2 11,21 31,40 19,1 32,6 91,4 55,6 6 The number of laboratories is the number after deletion of excessive-outlier laboratories. s ris the within-laboratory standard d
32、eviation (in measurement units); r is the repeatability, i.e. within-laboratory precision (in measurement units); (r) is the repeatability (in percent of mean level); s Ris the between-laboratory standard deviation (for the total between-laboratory variation in measurement units); R is the reproduci
33、bility, i.e. between-laboratory precision (in measurement units); (R) is the reproducibility (in percent of mean level). E.3 Additional comments For the cut-glove procedure, the analysis showed that two laboratories had excessive outliers. Although an outlier replacement operation was conducted usin
34、g ISO/TR 9272:1986 procedures, both repeatability and reproducibility were still quite poor. The results shown in Table E.1 for the cut-glove procedure are for the analysis with both outlying laboratories deleted from the database, i.e. for five participating laboratories. For the glove-in-glove pro
35、cedure, one of the same laboratories also had excessive outliers, which again resulted in poor precision. The results given in Table E.1 for the glove-in-glove procedure are for the analysis with this one laboratory deleted from the database, i.e. for six participating laboratories. E.4 Bias Bias is
36、 the difference between a measured average test result and a reference or true value for the measurement in question. Reference values do not exist for these procedures and, therefore, bias cannot be evaluated. 4 ISO 2012 All rights reserved ISO 12243:2003/Amd.1:2012(E) Page 17, Bibliography Delete
37、the reference to ISO 9272. Renumber the subsequent references. Add the following footnote reference at the end of the reference to ISO/TR 9272:1986: “ 2) ”. Insert the following footnote: “ 2)ISO/TR 9272:1986 has been withdrawn and replaced by ISO/TR 9272:2005.”. Replace new bibliographical reference to “ISO 11193-1:2002” with “ISO 11193-1”. ISO 2012 All rights reserved 5ISO 12243:2003/Amd.1:2012(E) ISO 2012 All rights reserved ICS 83.040.10 Price based on 5 pages
