Determination of residual organic solvents in Eszopiclone by headspace capillary gas chromatography

OBJECTIVE To determine a headspace capillary gas chromatography method for the determination of residual organic solvents(methanol,acetone,ethyl acetate) in Eszopiclone.METHODS The residual organic solvents were determined by GC with ZB-5 capillary column(30m×0.53mm×3μm),with FID detector,the injection port temperature was maintaining at 130℃ and that of the detector at 230℃.The initial column temperature was 40℃,maintaining it for 6min,then raising the temperature to 200℃ at a rate of 20℃·min-1 and maintaining it at 200℃ for 10min.The flow rate of N2 was 3 mL·min-1.The headspace injection was applied with the injection volume of l mL and the split ratio was set at 1∶5.DMSO was used as solvent media.RESULTS The calibration curves of methanol,acetone,ethyl acetate were linear in the concentration range of 14.91～303.12,25.14～500.40 and 25.20～503.24μg·mL-1,respectively.The LOQ of methanol,acetone,ethyl acetate were 1.52,0.71 and 1.26μg·mL-1.The average recoveries(n=9) of methanol,acetone,ethyl acetate were 100.8%(RSD=3.6%),99.5%(RSD=3.1%) and 98.5%(RSD=3.2%),respectively.CONCLUSION This method is economy and simple,the method proved to be sensitive and accurate.It is suitable for determination of organic solvents and in Eszopiclone.