Trace level quantification of 1-(3-chloropropyl)-4-(3-chlorophenyl)piperazine HCl genotoxic impurity in trazodone using LC–MS/MS

Abstract

A selective and sensitive liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed for the quantitative determination of 1-(3-chloropropyl)-4-(3-chlorophenyl)piperazine HCl (CCP HCl) a process related impurity in trazodone. The method provided excellent sensitivity at a typical target analyte level of <0.1 ppm, when the API samples were prepared at 5.0 mg/mL. The CCP HCl sample was analyzed on a C18 symmetry (100 mm × 4.6 mm, 3.5 μm) column interfaced with a triple quadruple tandem mass spectrometer operated in a multiple reaction monitoring (MRM) mode. Positive electro spray ionization (ESI) was employed as the ionization source and the mobile phase used was 5.0 mM ammonium acetate–acetonitrile (30:70, v/v). The injection precision of the lowest concentration standards was excellent with %RSD-1.42%. The calibration curve showed good linearity over the concentration range of 0.03–1.5 ppm with a correlation coefficient of >0.9996. Limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.01 and 0.03 ppm, respectively. The developed method was validated as per ICH guidelines in terms of LOD, LOQ, linearity, precision, accuracy, specificity and robustness.