The spectrophotometric method on the routine of 1,5-diphenylcarbazide was adjusted on chromium determination in faeces, after its utilization as a biological marker as chromium (III) oxide.

摘要

This study was undertaken to adjust the spectrophotometric method of 1,5-diphenylcarbazide for the determination of chromium in the faeces as a biological marker. The factors that could interfere with the transformation of chromium (III) into chromium (IV) were tested such as metal recovery, sample amount, amount and order of oxidant acid use of wet digestion, digestion temperature and digestion loss and chromium loss by volatilization as chromyl chloride. However, the interference of these factors were not statistically determined. In the adjusted method, the sample was classically digested by nitric/perchloric acid mixture, leading to the oxidation of chromium (III) to chromium (IV). An aliquot of the diluted extract was used for the reaction with 1,5-diphenylcarbazide. Absorbance was measured at 550 nm using 1-cm path length cuvettes. Potassium chromate was used as a reference substance to obtain the standard curve ranging from 0.25-2.5 mg/ml of Cr2O3 (one mg Cr2O3 degrees 1.935 mg K2Cr2O7).