The Spectrophotometric Determination of Chromium (vi) Using N, N-diethyl-p-phenylenediamine in Synthetically Prepared Wastewater, And Tap Water

Abstract

The DPD (N, N-diethyl-p-phenylenediamine) is introduced in the present study as an analytical reagent for the direct, rapid, easy, and sensitive spectrophotometric detection of hexavalent chromium Cr (VI) species which is health hazard. The oxidization of the colorless DPD (N, N-diethyl-pphenylenediamine) reagent with Cr (VI) results in a red color DPD radical (DPD •+ ) at pH 4.39. The color intensity is directly proportional to the Cr (VI) concentration. By utilizing a UV-Vis spectrophotometer, the measurement of the produced DPD •+ can be identified in term of quantity at 551 nm. The linear calibration graphs for 0.2 -2 mg. L −1 of Cr (VI) are obtained with a correlation coefficient value of 0.9997. The molar absorption coefficient and Sandell's sensitivity are 2.5449x10 4 L.mol −1 cm −1 and 0.028 mg. Cr (VI), cm −2 , respectively. The present work develops, optimizes, and validates a new spectrophotometric method for determining Cr (VI) in the samples of the synthetically prepared wastewater and tap water. The method is effectively applied and the findings are statistically evaluated with those of the reference method.