An HPLC method development for the assessment of degradation products of anthraquinone dye

This paper describes the development of a simple and sensitive method with reduced run time for the estimation of biodegradation product of an anthraquinone dye, Drimarene blue K(2)RL. The chromatographic analysis was performed using a reversed-phase high performance liquid chromatography (HPLC) with a Lichrospher® RP-18 column, 5 μm particle size, 25 cm × 4.6 mm internal diameter using a 70:20:10 (v/v) mixture of acetonitrile-ammonium acetate buffer (0.02 M) with 0.8% Trifluoroacetic acid (pH 2.5) and methanol as eluent. Flow rate was adjusted to 1.2 mL min(-1). The metabolites (phthalic acid, benzoic acid, 1, 4-dihydroxyanthraquinone, and 2,3-dihydro-9,10-dihydroxy-1,4-anthracenedione) were identified by running HPLC grade standards in defined concentrations. The retention time of the compounds were 2.0, 2.5, 5.2, and 7.2 min for phthalic acid, benzoic acid, 1, 4-dihydroxyanthraquinone, and 2,3-dihydro- 9,10-dihydroxy-1,4-anthracenedione, respectively. The reliability, sensitivity, and validation of the method were checked by calculating recoveries of the individual compounds in the acetonitrile and dye degradation media. The lower limits of detection for anthraquinone metabolites and the separation of acid and anthraquinone metabolites in short time were achieved.