Simultaneous identification and determination of eleven tyrosine kinase inhibitors by supercritical fluid chromatography- mass spectrometry

A rapid analytical method using supercritical fluid chromatography (SFC) coupled to mass spectrometry for the simultaneous identification and determination of eleven tyrosine kinase inhibitors (TKIs) was developed and validated. For quantitative assay, a tested solution with a high concentration of 0.4 mg mL−1 was applied for SFC determination. For identification purposes, a diluted solution with a concentration down to 1 μg mL−1 was introduced into a SFC-MS system to gain confirmative information. Six different columns were examined in this study and the best separation was achieved on an Acquity UPC2 Torus DIOL column (3.0 mm × 100 mm, 1.7 μm) using a gradient program. The effects of different additives, column temperature and back pressure were investigated. Negative and positive modes were compared using Xevo G2-XS QTOF after SFC separation. The results showed that the response of TKIs in positive mode was much higher than that in negative mode and thus positive mode was adopted. The method validation was performed in the concentration range of 1–600 μg mL−1 for all TKIs with a coefficient of determination (R2) greater than 0.9995. The developed method was applied to several samples collected from the market. Two out of them in powder form were identified to be afatinib with a content of 0.94 mg mg−1 and osimertinib with a content of 0.92 mg mg−1. Another sample in capsule form was identified to be osimertinib with a content of 57 mg per capsule.