Determination of Cr (VI) Content in Water-Soluble Dyes

Hexavalent chromium detection in the presence of high load of colorants is a challenge, and it is an important area of study. Colorants are a class of interfering substance in many spectroscopic analysis and chromatographic separation and detection. In this study, a method has been developed to separate out Cr (VI) and water-soluble dyes by using activated charcoal as an absorption medium. The extraction procedure was optimized with Cr (VI) standard solution for quantification. The efficacy of the extraction procedure for the removal of water-soluble dyes and detection of Cr (VI) was checked with a spike recovery study. Based on the spike recovery study, the method has been validated as per the international validation protocol. The method is simple, cost effective and has a detection limit down up to 3.0 mg/kg. The recovery rate of Cr (VI) in water-soluble dyes like reactive yellow HE 6G, reactive red 218, turquoise blue HGN, reactive navy blue RX and reactive black 5A was found to be more than 90% with a good repeatability and reproducibility.