GC-MS法测定维格列汀中氨基甲酸乙酯残留的不确定

目的 用气相-质谱联用（GC-MS）法对维格列汀中氨基甲酸乙酯残留的测定进行不确定度评估。方法 结合氨基甲酸乙酯的实验方法，建立数学模型，对实验过程中供试品制备、对照品溶液的配制、样品测量结果的重复性、样品回收率中不确定度来源进行分析。结果 GC-MS法测定维格列汀中氨基甲酸乙酯时，当取样量为200 mg，k=2（95%置信度），测量结果表述为：（2.423±0.069）mg/kg。供试品的制备、标准溶液配制过程、重复性、方法回收率对总的不确定度贡献分别为10.33%、15.08%、56.88%、17.71%。结论 氨基甲酸乙酯在测定过程中，供试品制备、对照品溶液的配制、方法回收率对总的不确定度影响较小，样品的重复测量是影响测量结果不确定度的主要来源，在实验过程中应给予控制。

Uncertainty evaluation of determination of methyl methanesulfonate residues in vildagliptin by GC-MS

Objective To evaluate the uncertainty of measurement of ethyl carbamate residues by gas chromatography-mass spectroscopy (GC-MS). Methods To test the ethyl carbamate residues, a mathematical model was established. The preparation of test solution, preparation of reference solution, repeatability of sample measurement results and in sample recovery for the source of uncertainty were analyzed. Results when the amount of sample was 200 mg, k=2 (95% confidence), the result was expressed as:(2.423 ±0.069) mg/kg. The contribution of preparation of test sample, preparation process of standard solution, repeatability and method recovery to the total uncertainty was 10.33%, 15.08%, 56.88% and 17.71%, respectively. Conclusion Preparation of test solution, preparation of reference solution and sample recovery have little influence for the results, while the repeated measurement are the main factors affecting the uncertainty of the results of detection and analysis of ethyl carbamate residues, and should be given special attention and control during the experiment.