提出了气相色谱-三重四极杆串联质谱法测定鲜食用菌中尼古丁和可替宁含量的方法。称取5.00g样品,加入丙酮5.00mL和2.0mg·L^-1内标(二苯胺)溶液25μL,涡旋1min,加入含6g硫酸镁和1.5g乙酸钠的QuEChERS试剂包,涡旋1min,离心5min,上清液经0.45μm聚四氟乙烯针式过滤器过滤,取滤液待测。以柱升温程序分离尼古丁和可替宁,以质荷比(m/z)162.10/84.10和m/z 176.10/98.10为定量离子对,采用多反应监测模式扫描,内标法定量。结果显示:尼古丁和可替宁均存在基质增强效应,工作曲线的线性范围均为5.0~200.0μg·L^-1,检出限分别为0.5,2.0μg·kg^-1;对空白样品进行加标回收试验,尼古丁和可替宁的回收率分别为97.5%~108%和96.7%~120%,测定值的相对标准偏差(n=6)分别为3.6%~7.7%和2.9%~7.2%;方法用于15份鲜食用菌样品分析,其中有13份样品检出尼古丁,检出量为0.0009~0.0380mg·kg^-1,均未检出可替宁。

A method for the determination of nicotine and cotinine in fresh edible fungi by gas chromatography-triple quadrupole tandem mass spectrometry was proposed. The sample (5.00 g) was taken, and 5.00 mL of acetone and 25 μL of 2.0 mg·L^-1 internal standard (diphenylamine) solution were added. The above mixture was vortexed for 1 min, and the QuEChERS reagent kit containing 6 g of magnesium sulfate and 1.5 g of sodium acetate was added. After vortex for 1 min and centrifugation for 5 min, the supernatant was filtered through 0.45 μm teflon needle filter, and the filtrate was taken for test. Nicotine and cotinine were separated with column heating program, and mass-to-charge ratio (m/z) 162.10/84.10 and m/z 176.10/98.10 were used as quantification ion pairs, with multiple reaction monitoring mode for scanning and internal standard method for quantification. It was shown that both nicotine and cotinine had matrix enhancement effect, and the linear ranges of working curves were 5.0-200.0 μg·L^-1, with detection limits of 0.5, 2.0 μg·kg^-1, respectively. Test for recovery was made on the blank sample, giving results in the ranges of 97.5%-108% for nicotine and 96.7%-120% for cotinine, and RSDs (n=6) of the determined values were in the ranges of 3.6%-7.7% for nicotine and 2.9%-7.2% for cotinine, respectively. This method was applied to the analysis of 15 fresh edible fungi samples. Nicotine was detected in 13 of them, with detection amounts ranging from 0.000 9 mg·kg^-1 to 0.038 0 mg·kg^-1, and cotinine was not detected.