Detection of sitagliptin via derivatization employing n-methyl-n-(trimethylsilyl)trifluoroacetamide using gas chromatography-mass spectrometry

Sitagliptin comes under the class of anti-diabetic drug, dipeptidyl peptidase-4 (DDP-4) inhibitor used in the treatment of Type 2 diabetes mellitus. The detection method for sitagliptin from biological matrices was developed employing gas chromatography-mass spectrometry (GC-MS. Distinct derivatization techniques were approached for the sample preparation for GC-MS analysis i.e. Silylation and Acylation. Derivatization method was optimized and developed under different conditions, i.e. reaction temperature and reaction time. N-Methyl-N-(trimethylsilyl) trifluoroacetamide [MSTFA] was found to be the most suitable derivatization reagent prior to the GC-MS analysis of sitagliptin. Sitagliptin was extracted from the viscera sample using liquid-liquid extraction via back extraction method employing 1-butanol: hexane (50:50, v/v). Ion base peak of trimethylsilyl (TMS) derivative of sitagliptin with m/z ratio of 334 was monitored using total ion current (TIC) mode. Various parameters like specificity, carryover, stability, precision, accuracy, robustness and ruggedness were evaluated for validating the identification method. The GC-MS method is found to be linear and illustrated within the range 500ng/ml to 2500ng/ml with the value of R2 (coefficient of determination) at 0.9916. Precision (%) for the interday and intraday analysis found to be in the suitable spectrum. Therefore, the proposed GC-MS method can be used for the detection of sitagliptin in biological matrices.