Novel and Validated Spectrophotometric Matrix Matching Method for Simple and Rapid Determination of Chromium in Oily Media

Guang Pu Xue Yu Guang Pu Fen Xi. 2016 May;36(5):1634-8.

Abstract

N,N’-bis(4-methoxysalicylidene) ethylenediamine is proposed as analytical reagent for the direct determination of chromium in original matrix of liquid oils. The method is based on the complexation of N,N’-bis(4-methoxysalicylidene) ethylenediamine and chromium in n-hexane∶acetone (1∶4) medium and spectrophotometric determination at 355 nm against reagent blank. Complexation of MSE and chromium is completed in 20 seconds at molar ratio 1∶1. The molar absorptivity and the formation constant of the complex are determined as 9 740 L·mol-1·cm-1 and 3.6(±0.1)×105, respectively. Beer’s law is obeyed in range 0.02~1.50 mg·L-1 chromium concentration. Limits of detection and quantification of the suggested method were 7.5 and 25.1 μg·kg-1, respectively. The accuracy and precision of the method was checked by finding mean recovery and relative standard deviation by oil-based chromium standard analysis as 96.4%±1.4% and 1.5%, respectively. The practical applicability of elaborate method was tested using oil-based chromium standard spiked and unspiked corn, sunflower, soybean, olive and canola oils.