气相色谱-质谱法分析环境空气中甲醇和丙酮
Determination of Methanol and Acetone in Ambient Air by Gas Chromatography-mass Spectrometry
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摘要:目的 建立环境空气中甲醇、丙酮的气相色谱-质谱测定方法。方法 环境空气中的甲醇和丙酮经硅胶管采样, 甲苯溶剂解吸后, 用气相色谱-质谱法分析。采用选择离子扫描方式检测, 用甲醇、丙酮的保留时间和特征离子定性, 外标法峰面积定量。结果 甲醇和丙酮的方法检出限分别为1.2×10-4 μg和7.3×10-5 μg, 测定下限分别为4.0×10-4 μg和2.5×10-4 μg。按采样体积5 L计, 甲醇和丙酮的测量浓度范围分别为0.08 mg/m3~10.0 mg/m3和0.05 mg/m3~10.0 mg/m3, 方法的相对标准偏差分别为1.3%~4.2%和1.1%~3.2%, 加标回收率分别为91.8%~102.7%和85.3%~100.7%。结论 本方法采样方便, 测定灵敏、准确, 可用于环境空气中甲醇和丙酮的测定。Abstract:Objectives To establish a method for the determination of methanol and acetone in ambient air by gas chromatography-mass spectrometry.Methods Air samples for methanol and acetone in ambient air were collected into silica gel tubes by pumping and then desorbed and extracted by methylbenzene, the levels of methanol and acetone were analyzed by gas chromatography-mass spectrometry with selected ion monitoring method.Results The detection limits for methanol and acetone were 1.2×10-4 μg and 7.3×10-5 μg respectively; and the quantification limits were 4.0×10-4 μg and 2.5×10-4 μg respectively. The linear range of the method for methanol and acetone were 0.08~10.0 mg/m3 and 0.05~10.0 mg/m3 respectively in 5 L of air. The relative standard deviation of methanol was 1.3%~4.2%, while the recovery rate was in the range of 92.8%~99.1%. The relative standard deviation of acetone was 1.1%~3.2% while the recovery rate was in the range of 87.3%~98.1%.Conclusions The method is simple, sensitive, accurate and is applicable to the determination of methanol and acetone in ambient air.
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