头发中尼古丁和可的宁的气相色谱-质谱测定法

Determination of nicotine and its metabolite of cotinine in hair by gas chromatography-mass spectrometry

目的建立气相色谱-质谱法同时测定头发中尼古丁及其主要代谢产物可的宁的方法。方法将清洗、晾干后的发样剪碎,加入内标物喹啉,用氢氧化钠、超声波处理,置37℃温箱消解,用甲醇和二氯甲烷混合溶剂(1∶3)提取,取二氯甲烷层氮气吹干定容后,用气相色谱-质谱法对尼古丁及其代谢产物可的宁进行测定,标准曲线法定量。结果在优化发样提取和色谱分析条件下,尼古丁和可的宁的线性范围分别为1.2 ng/ml^1 mg/ml和2.3 ng/ml^2 mg/ml,标准曲线的相关系数分别为0.999 8和0.999 7;对于0.1 g头发,该方法的检出限尼古丁为3.6 ng/g,可的宁为6.9 ng/g;测定的相对标准偏差(RSD)分别为4.8%~6.3%和3.2%~7.3%,加标回收率在93.67%~93.92%和102.1%~103.2%之间。结论气相色谱-质谱法具有灵敏度高,检出限低,分析时间短,定性和定量准确等特点,本课题可以为进一步的流行病学研究提供实验室数据和资料。

[Objective]To develop a method for determination of nicotine and its metabolite cotinine in hair by gas chromatogra-phy-mass spectrometry.[Methods]After cleaning and drying,the hair sample was cut up,and digested by sodium hydroxide and ultrasonic wave in 37 ℃ thermostat. Nicotine and cotinine in hair sample were extracted with a mixing solvent of dichloromethane-methanol（1 ∶3）. The extraction solution was vaporized with nitrogen flow and diluted to volume. Gas chromatography-mass spectrometry（GC-MS） for quantitative determination of nicotine and its metabolite cotinine was conducted by using standard curve.[Results] By using optimization of sample extraction and chromatographic analysis,the linear ranges of nicotine and cotinine for GC-MS were 1.2 ng/ml-1 mg/ml and 2.3 ng/ml-2 mg/ml respectively. The correlation coefficients were 0.999 6 and0.999 7. And the detection limits of the two were 3.6 ng/g and 6.9 ng/g in 0.1g hair. The range of RSD were 4.8%-6.3% and 3.2%-7.3%,and the recoveries were 93.67%-93.92% and 102.1%-103.2%.[Conclusion]The GC-MS method has the advantages of high sensitivity,low detection limit,short analysis time,qualitative and quantitative determination accuracy. This study can provide laboratory data for further epidemiologic studies.