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Critical appraisal of analytical procedures for the determination of CR(VI) in dyed leathers by 1,5 diphenylcarbazide spectrophotometry after sample dilutin or color removal / J. Scancar in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CII, N° 3 (03/2007)
[article]
Titre : Critical appraisal of analytical procedures for the determination of CR(VI) in dyed leathers by 1,5 diphenylcarbazide spectrophotometry after sample dilutin or color removal Type de document : texte imprimé Auteurs : J. Scancar, Auteur ; R. Milacic, Auteur ; N. Bukovec, Auteur ; T. Osterman, Auteur Année de publication : 2007 Article en page(s) : p. 85-92 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Colored chemical species in leather extracts may contribute to the measurement signal in spectrophotometric determination of Cr(VI), resulting in false positive Cr(VI) concentrations. In the present work the efficiency of sample dilution, or color removal by the use of RP C18 columns and columns filled with florisil, to reduce color interferences prior to spectrophotometric determinations of Cr(VI) in dyed leathers were evaluated. Limits of detections were 2.5 mg kg-1 Cr(VI) when samples were diluted (1:5) and 0.5 mg kg-1 Cr(VI) after color removal by RP C18 or florisil. In all procedures applied repeatability and reproducibility of measurements were better than ± 5 %. The accuracy of the 1,5 diphenylcarbazide spectrophotometric determination of Cr(VI) was tested by analysis of the certified reference material CRM 544, Cr(VI) in lyophilized solution. By spiking leather extracts it was experimentally proven that the use of decolorizing agents did not change Cr(VI) speciation. The experimental data also indicated that in some of the leather extracts analyzed colored species caused severe positive interference effects that could not be reduced by dilution or the use of RP C18. Florisil was found to be an efficient decolorizing agent and enabled accurate and reliable determination of Cr(VI) in dyed leathers by 1,5 diphenylcarbazide spectrophotometry. En ligne : https://drive.google.com/file/d/1wEa6iB2_-GBRgPmRvj5TyguS-TjxINaQ/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3364
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CII, N° 3 (03/2007) . - p. 85-92[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 007160 - Périodique Bibliothèque principale Documentaires Disponible Is spectrophotometry a reliable technique for determination of Cr(VI) in leather samples ? / R. Milacic in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 82, N° 3 (05-06/1998)
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Titre : Is spectrophotometry a reliable technique for determination of Cr(VI) in leather samples ? Type de document : texte imprimé Auteurs : R. Milacic, Auteur ; J. Scancar, Auteur ; M. Urbanc, Auteur Année de publication : 1998 Article en page(s) : p. 91-94 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Chromium (VI) in coloured and non-coloured leather samples was determined by the standard spectrophotometric procedure DIN 53314 and also by extraction of the chromium (VI)-HC1 complex (277 K) into methyl isobutyl ketone (MIBK). Chromium (VI) was determined in the organic phase by flame atomic absorption spectrometry (FAAS). Both techniques were found to be sensitive enough for the determination of chromium (VI) in the samples analysed. The limit of detection for the spectrophotometry was 2.0 mg Cr(VI) kg-1 and for MIBK extraction 0.2 mg Cr(VI) kg-1 of leather.
The interference effects of coloured species in leather extracts were investigated by employing the spectrophotometric technique. For this purpose diluted and non-diluted sample extracts were analysed. The results obtained were critically evaluated and compared to the MIBK extraction technique.
The applicability of the spectrophotometric procedure for determination of chromium (VI) in coloured leather samples was estimated.Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=7900
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 82, N° 3 (05-06/1998) . - p. 91-94[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 007022 - Périodique Bibliothèque principale Documentaires Disponible