ExtractionFree IonPair Methods for the Assay of

Authors: K N Prashanth N Swamy K Basavaiah

Publish Date: 2014/11/07

Volume: 81, Issue: 5, Pages: 893-902

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Abstract

Three simple and sensitive extractionfree spectrophotometric methods are described for the determination of trifluoperazine dihydrochloride TFH The methods are based on ion pair complex formation between the nitrogenous compound trifluoperazine TFP converted from trifluoperazine dihydrochloride and sulfonphthalein dyes namely bromocresol green BCG bromothymol blue BTB and bromophenol blue BPB in dichloromethane medium in which all the above experimental variables were circumvented The colored products are measured at 425 nm in the BCG method 415 nm in the BTB method and 420 nm in the BPB method The stoichiometry of the ionpair complexes formed between the drug and dye 11 was determined by Job’s continuous variations method and the stability constants of the complexes were also calculated These methods quantify TFP over the concentration ranges of 125–200 μg/ml in the BCG method 15–210 μg/ml in the BTB method and 15–180 μg/ml in the BPB method The molar absorptivity l·mol–1·cm–1 and Sandell sensitivity ng/cm2 were calculated to be 206·104 and 00197 182·104 and 00224 and 222·104 and 00183 for the BCG BTB and BPB methods respectively The methods were successfully applied to the determination of TFP in pure drug pharmaceuticals and in spiked human urine with good accuracy and precision

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