Detection and Quantitation of Trace Phenolphthalein (in Pharmaceutical Preparations and in Forensic Exhibits) by Liquid Chromatography–Tandem Mass Spectrometry, a Sensitive and Accurate Method


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Kakali Sharma, M.Sc.

Assistant Professor

Department of Chemistry

Vivekananda Mahavidyalaya

Haripal, Hooghly

West Bengal 712405




Phenolphthalein, an acid–base indicator and laxative, is important as a constituent of widely used weight-reducing multicomponent food formulations. Phenolphthalein is an useful reagent in forensic science for the identification of blood stains of suspected victims and for apprehending erring officials accepting bribes in graft or trap cases. The pink-colored alkaline hand washes originating from the phenolphthalein-smeared notes can easily be determined spectrophotometrically. But in many cases, colored solution turns colorless with time, which renders the genuineness of bribe cases doubtful to the judiciary. No method is known till now for the detection and identification of phenolphthalein in colorless forensic exhibits with positive proof. Liquid chromatography–tandem mass spectrometry had been found to be most sensitive, accurate method capable of detection and quantitation of trace phenolphthalein in commercial formulations and colorless forensic exhibits with positive proof. The detection limit of phenolphthalein was found to be 1.66 pg/L or ng/mL, and the calibration curve shows good linearity (r2 = 0.9974).