Development and validation of GC–MS method for the determination of methyl methanesulfonate and ethyl methanesulfonate in imatinib mesylate

A gas chromatography–mass spectrometry (GC–MS) method has been developed for the identification and determination of two carcinogenic and genotoxic mesylate esters viz. methyl methanesulfonate (MMS) and ethyl methanesulfonate (EMS) in imatinib mesylate (INM). The method was optimized based on the peak shapes and resolution of MMS and EMS. The method was validated as per International Conference of Harmonization (ICH) guidelines in terms of limits of detection (LOD), limit of quantitation (LOQ), linearity, precision, accuracy, specificity and robustness. The LOD and LOQ values were found to be 0.3 and 1.0 μg/ml, respectively. The method is linear within the range of 1–15 μg/ml for both the compounds. These mesylate esters were not found in three different batches of pure and pharmaceutical formulations of INM.