[article]
| Titre : |
Fractionation of Cr and determination of Cr(VI) in blue shavings |
| Type de document : |
texte imprimé |
| Auteurs : |
R. Milacic, Auteur ; Janez Stupar, Auteur ; Nevenka Kozuh, Auteur |
| Année de publication : |
1992 |
| Article en page(s) : |
p. 221-232 |
| Note générale : |
Bibliogr. |
| Langues : |
Américain (ame) |
| Index. décimale : |
675 Technologie du cuir et de la fourrure |
| Résumé : |
Blue shavings are a protein-based matrix with a high content of chromium(III) salts and organic polymers.If they contain excessive amounts of chromium(VI) they could be a potentially hazardous waste in the environment.Fractionation of chromium in blue shavings was studied by employing various sequential extraction procedures to determine the water soluble,exchangeable,organically bound,carbonate,crystalline, hydroxide and sulphide fractions.Chromium(VI) was determined in the phosphate buffer extractable(pH=6.5-7.0) fraction.
Results obtained by several analytical techniques indicate limitations in the determination of Cr(VI).Ion-pairing reversed phase HPLC combined with flame or electrothermal AAS was found to be affected by severe matrix effects due to organic polymers in blue shavings and high salt concentrations in the buffer and extractant solutions.Chelating ion-exchange and ion-exchange chromatography combined with flame AAS detection gave over-estimated results due to inefficient retention of inert Cr(III) complexes.Spectrophotometry(addition of diphenylcarbazide reagent to the analyte prior to acidification) and extraction of Cr(VI)-HC1 complex into MIBK(277K) gave generally comparable and reliable results.The detection limit for the former technique was 2 ng cm(-3) and 15 ng cm(-3) for the latter.Our investigations indicate that over 90 percent of total chromium in blue shavings is in chemically inert form,approxymately 8 percent is extracted with Na4P2O7 while less than 0.003 percent exists in the toxic chromate form. |
| En ligne : |
https://drive.google.com/file/d/1h15lkLO0eXXzNFGmURWR9ibxLcnpkr0t/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=8310 |
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > LXXXVII, N° 6 (06/1992) . - p. 221-232
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