石墨消解-动态反应池模式-电感耦合等离子体质谱法测定烟用香精和料液中5种元素的含量

Determination of 5 Elements in Tobacco Flavor and Liquor by Inductively Coupled Plasma Mass Spectrometry with Graphite Digestion and Dynamic Reaction Cell Mode

将烟用香精和料液样品0.3 g(精确至0.001 g)置于全自动石墨消解仪消解罐中,分3次加入消解液(共计10 mL硝酸、1 mL高氯酸),在170℃的最高消解温度下,样品消解完全.所得溶液用水定容至50 mL,采用电感耦合等离子体质谱法(ICP-MS)测定其中砷、铅、镉、铬、镍等元素的含量.以铟为内标,铬、镉、镍、铅、砷元素的测量同位素分别为^(52)Cr、^(111)Cd、^(60)Ni、^(208)Pb、^(75)As,使用动态反应池(DRC)模式消除了铬、砷元素的质谱干扰,铬、镉、镍、铅等元素的测定选择氦气碰撞模式,砷元素的测定选择氢气反应模式.结果表明,5种元素的质量浓度在一定范围内与各元素与内标计数值的比值呈线性关系,检出限(3s)为0.016~0.035 mg·kg^(-1).按标准加入法进行回收试验,各元素回收率为91.5%~111%,相对标准偏差(n=6)为0.28%~3.1%.方法用于10个烟用香精和料液样品的分析,铬、砷、镍的检出量分别为0.019~0.061 mg·kg^(-1),0.039~0.061 mg·kg^(-1)和0.022~0.031 mg·kg^(-1),镉和铅未检出.

The tobacco flavor and liquor sample(0.3 g,accurate to 0.001 g)was placed into the digestion tank of an automatic graphite digestion instrument,and 10 mL of nitric acid and 1 mL of perchloric acid in total were added three times as digestion solution.The sample was completely digested at the maximum digestion temperature of 170℃,then the obtained solution was made its volume up to 50 mL by water,and arsenic,lead,cadmium,chromium and nickel in the solution were determined by inductively coupled plasma mass spectrometry(ICP-MS).The determined isotopes of chromium,cadmium,nickel,lead and arsenic were ^(52)Cr,^(111)Cd,^(60)Ni,^(208)Pb and ^(75)As,respectively,with indium as internal standard element,and dynamic reaction cell(DRC)mode was used to eliminate the mass spectral interference of chromium and arsenic.Helium collision mode was used for determination of chromium,cadmium,nickel and lead,while hydrogen reaction mode was used for determination of arsenic.As shown by the results,linear relationships between the mass concentrations of 5 element and the count values ratio of each element to the internal standard were found in definite ranges,with detection limits(3s)in the range of 0.016-0.035 mg·kg^(-1).Test for recovery was made by standard addition method,giving results in the range of 91.5%-111%,with RSDs(n=6)of the determined values ranged from 0.28%to 3.1%.The proposed method was applied to analysis of 10 tobacco flavor and liquor samples.The detected amounts of chromium,arsenic and nickel were 0.019-0.061 mg·kg^(-1),0.039-0.061 mg·kg^(-1) and 0.022-0.031 mg·kg^(-1),respectively,while cadmium and lead were not detected.