OBJECTIVE To establish a new derivatization headspace gas chromatography-flame ionization detection (HS-GC-FID) method to detect the residual amount of dimethyl sulfate in neostigmine methylsulfate bulk drug. METHODS Various derivatization methods were screened and then optimized. n-Butanol was used as the derivatization agent and methylated with dimethyl sulfate at the temperature of 50 ℃, producing the derivatization product methyl n-butyl ether. The analytical column was DB-624 (0.32 mm×30 m, 1.8 μm). The column temperature was maintained at 40 ℃, holding for 8 min, then was raised to 220 ℃ at the rate of 30 ℃·min-1, holding for 2 min. The flow rate of carrier gas nitrogen was 2.0 mL·min-1. The detection was achieved in FID with the injection port temperature of 200 ℃ and the detector temperature of 230 ℃. RESULTS Neostigmine methylsulfate showed no false positive interference with the detection of dimethyl sulfate. The calibration curve of dimethyl sulfate had good linearity over the range of 6.066 to 151.7 μg·mL-1 (r2=0.999 9). The average recovery of dimethyl sulfate was 99.9%, and the RSD was 2.6%(n=9). CONCLUSION This method exhibits good specificity, simplicity, and high accuracy, and it can be used for the determination of genotoxic impurity dimethyl sulfate in neostigmine methylsulfate bulk drug.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |