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Further studies on the official methods of analysis for determination of hexavalent chromium level in leather / Dipankar Chauduri in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVIII, N° 10 (10/2003)
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Titre : Further studies on the official methods of analysis for determination of hexavalent chromium level in leather Type de document : texte imprimé Auteurs : Dipankar Chauduri, Auteur ; Ratna Chakraborti, Auteur ; Pinaki Bhattacharya, Auteur Année de publication : 2003 Article en page(s) : p. 388-399 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : This study was carried out primarily to have a better understanding of some of the reported limitations of the official methods of analysis for determining the level of Cr(VI) in leather. In this investigation the stability of Cr(VI) and Cr(III) was tested in several potential extractants and leather extracts. But no redox reactions could be observed in any of the liquors tested. Experiments were also conducted to determine the optimum stirring time for complete extraction of Cr(VI) from leather. The results reveal that a stirring time of 3 hours is insufficient for full chrome leather. In order to determine the kind of change necessary in the extraction procedure to avoid the potential oxidation of Cr(III) during extraction, experiments were also conducted on extraction with phosphate buffer for different time intervals under various pH conditions. The results indicate that more reliable analytical results may be obtained by extracting the sample for 6 hours with phosphate buffer at pH 6.4-6.6. En ligne : https://drive.google.com/file/d/1IcXFPvLBEkR71CdqEFFAAMV953RazfqC/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4153
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCVIII, N° 10 (10/2003) . - p. 388-399[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 001592 - Périodique Bibliothèque principale Documentaires Disponible How much Cr(VI) is formed during extraction of leather with phospahte buffer ? / Dipankar Chaudhuri in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCIX, N° 3 (03/2004)
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Titre : How much Cr(VI) is formed during extraction of leather with phospahte buffer ? Type de document : texte imprimé Auteurs : Dipankar Chaudhuri, Auteur ; Ratna Chakraborti, Auteur ; Pinaki Bhattacharya, Auteur Année de publication : 2004 Article en page(s) : p. 119-128 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Hexavalent chromium is not used at any stage of leather processing and leather possesses a reducing property. Therefore, hexavalent chromium is not likely to be present in leather. Nevertheless, Cr(VI) has been reported to be present. At the moment it is not clear whether the positive test results are indeed the consequence of hexavalent chromium extraction from leather or not. Despite this, Cr(VI) formation during extraction has been suggested as a probable reason for most of the positive test results. In the present investigation, leather analyses were carried out using different buffer solutions and also the same buffer solution at different pH values. Analysis for Cr(VI) was carried out under simulated extraction conditions also. The results of all these experiments indicate that the amount of Cr(VI) formed during extraction is too little to be considered as an important reason behind testing that yields positive findings of Cr(VI). En ligne : https://drive.google.com/file/d/1DJ0JaI4niISgvsrnE-Mn2FecHlJVf7P2/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4186
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCIX, N° 3 (03/2004) . - p. 119-128[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 001599 - Périodique Bibliothèque principale Documentaires Disponible