A new LC-MS Method for the Determination of p-Chloroaniline and (S)-5-Chloro-α-(cyclopropylethynyl)-2- Amino-α- (trifluoromethyl) Benzene Methanol in Efavirenz Bulk Form

The main objective of the present research study is to develop and validate a sensitive, specific, accurate and precise LC-MS method for the determination of p-Chloroaniline and (S)-5-Chloro-α-(cyclopropylethynyl)-2- amino-α- (trifluoromethyl) benzene methanol in Efavirenz bulk form. The effective separation of p-Chloroaniline and (S)-5-Chloro-α-(cyclopropylethynyl)-2- amino-α- (trifluoromethyl) benzene methanol were achieved by using Hypersil BDS (C18, 100 x 4.6 mm, 3 µm) column and a solvent system of Buffer (0.1% Formic acid in water): Methanol (30:70 v/v) with a flow rate of 0.4 ml/min. The p-Chloroaniline and (S)-5-Chloro-α-(cyclopropylethynyl)-2- amino-α-(trifluoromethyl) benzene methanol were monitored on mass spectrometer coupled with atmospheric pressure chemical ionization, positive polarity mode and quadrapole mass analyzer. The Retention time of p-Chloroaniline, (S)-5-Chloro-α-(cyclopropylethynyl)-2- amino-α- (trifluoromethyl) benzene methanol and Efavirenz were found at 5.7min, 7.6min and 11.1min resepectively. The detection limit and quantification limit were observed at 0.25ppm and 0.75 ppm respectively for both p-Chloroaniline and (S)-5-Chloro-α-(cyclopropylethynyl)-2- amino-α-(trifluoromethyl) benzene methanol. Those analytes were linear in the concentration ranges from 0.75ppm to 3.75ppm and the percentage relative standard deviation of six replicates of same concentrations of both the analytes were less than 10%. Hence this method was effective in separation and determination of p-Chloroaniline and (S)-5-Chloro-α-(cyclopropylethynyl)-2- amino-α- (trifluoromethyl) benzene methanol in Efavirenz.