| Résumé : |
The determination of zirconium and aluminium in solution has been documented previously and the complexometric titration method for zirconium using EDTA has proved successful for rapid and single analyses of both tanning baths and leather in this laboratory. During experiments with zirconium tanning in the presence of high concentrations of aluminium, a method was developed for determining both metals, with one simple titration, without the usual need to separate the two prior to analysis.
The preferred method of analysis for aluminium when titrating with EDTA involves a back-titration in the presence of excess EDTA. Determination of aluminium by direct titration, due to its slow reaction with the low concentration of EDTA available at acid pH., causes difficulty in assessing the end-point. Also, the interference by aluminium in the titration of zirconium with EDTA is due to some reaction of the aluminium under the titration conditions. As this reaction is slow and pH-dependent, a study of titre versus pH was undertaken to determine if there were conditions where each metal could be titrated independently of the other. The method developed gave reduced accuracy for aluminium analysis compared with the back-titration method or with the standard method using CDTA as titrant. |
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A simple method for the combined determination of both zirconium and aluminium in leather and tanning solutions in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. N° 71 (Année 1987)
