Method validation by collaborative trial for the quantification of binary mixtures containing polyamide and a novel polypropylene/polyamide bicomponent fibre.

A method for the quantification of a novel polypropylene/polyamide bicomponent fibre in binary mixtures with polyamide was subjected to validation by collaborative trial conducted at European level. Considering the probable acceptance of the novel fibre in Europe, this method is needed for consumer protection to allow market surveillance and antifraud controls. The aim of the study was to extend the scope of application of method 11 of Directive 96/73/EC, based on the selective dissolution of one of the components in binary mixtures. The method foresaw sample treatment with 75 % m/m sulfuric acid at room temperature for a contact time of 1 h. In order to ensure accurate quantification of the blends under investigation, the washing procedure had to be modified with the addition of two rinsings of the residue with the reagent used for the dissolution. Following ISO 5725, a balanced uniform level test was performed on loop twisted carpet samples of three levels of concentration (25, 50 and 75 %, approximately) with the participation of seventeen European laboratories. The trueness was evaluated considering as reference values data obtained from manual separation of samples. The calculated bias varied from 0.06 to 0.49 %, rising with the increasing content of polyamide in the binary mixture. Repeatability and reproducibility limits were in the range 0.69 - 1.04 % and 0.97 - 1.87 %, respectively. In agreement with the members of the European Network of National Experts on Textile Labelling, the optimised method was judged fit-for-purpose and the reproducibility limit was established at 2 %. Based on this study, the scope of application of method 11 can be extended with the insertion of the novel fibre as the insoluble component (d factor 1.005) and polyamide as the soluble one, provided that the modifications are adopted.

PICCININI Paola;  TRANTALLIDI Marilena;  ALVAREZ SARANDES LAVANDERA Rafael;  DE SERTORIO Maria; 

2012-02-03

SAGE PUBLICATIONS LTD

JRC64088

0040-5175,   

http://trj.sagepub.com/content/81/20/2160.refs,    https://publications.jrc.ec.europa.eu/repository/handle/JRC64088,   

10.1177/0040517511416281,