Determination of residual impurities in pharmaceutical excipient cetomacrogol 1000 by gas chromatography

For the quality control of cetomacrogol 1000, a gas chromatographic method for the determination of residual impurities in cetomacrogol 1000, such as ethylene oxide, 1, 4-dioxane, ethylene glycol, diethylene glycol and triethylene glycol, was established and validated.The DB-1 column with headspace injection was used to detect ethylene oxide and 1, 4-dioxane with the inlet temperature of 150 °C, the FID temperature of 250 °C, the headspace equilibration temperature of 70 °C and the equilibration time of 45 min.The VF-17MS column with liquid injection was used to detect ethylene glycol, diethylene glycol and triethylene glycol with the inlet temperature of 270 °C, and the FID temperature of 290 °C.The results showed that ethylene oxide and 1,4-dioxane have a good linearity within their specified addition amount ranges (r > 0.999), with the RSD of precision of below 8.0% and the average recovery rates of 90.6% and 101.2%; and that ethylene glycol, diethylene glycol and triethylene glycol also have a good linearity between 3 ? 60 μg/mL (r > 0.999), with the RSD of precision of below 3.0%, and the recovery rates of 96% ~ 103%.The method established in this study has good specificity, linearity, precision and recovery rate, which can effectively detect the multi-component and trace impurities.