Determination of Six Kinds of Residual Solvents in Pitavastatin Calcium by Headspace Solid Phase Microextraction Combined with Gas Chromatography

The sample was dissolved with N,N-dimethylformamide to prepare a sample solution of 100 g·L^-1. The sample solution (10 mL) was taken into a headspace vial and heated in a water bath at 40℃ for 5 min. Then solid-phase microextraction was carried out at 40℃ using polydimethylsiloxane extraction head, with adsorption time and desorption time of 30, 10 s, respectively. Methanol, tetrahydrofuran, ethyl acetate, ethanol, acetonitrile, and toluene were separated on a SE-54 capillary column and detected using a flame ionization detector. Linear relationships were found between peak areas and mass concentrations of the above six solvents within definite ranges, with detection limits (3S/N) in the range of 1.0-2.3 mg·L^-1. Values of recovery obtained by standard addition method ranged from 95.8% to 104%, and RSDs (n=8) were less than 9.0%.