电感耦合等离子体-质谱法测定枸橼酸三乙酯中7种元素杂质

Determination of Seven Elemental Impurities in Triethyl Citrate by ICP-MS

目的建立测定枸橼酸三乙酯中镉(Cd)、铅(Pb)、砷(As)、汞(Hg)、钴(Co)、钒(V)、镍(Ni)7种元素杂质残留量的电感耦合等离子体-质谱法。方法采用在线内标法,载气为氦气,等离子体模式为HMI-8,载气、雾化气、辅助气流量均为0.8 L/min,等离子气流量为15.0 L/min,蠕动泵转速为0.10 r/min,雾化室温度为2℃。结果V,Co,Ni,As,Cd,Pb元素的质量浓度在0~20.0 ng/mL范围内,Hg元素的质量浓度在0~5.0 ng/mL范围内,与仪器响应值线性关系良好(r≥0.9995,n=7);精密度试验结果的RSD均小于3%(n=6);加样回收率分别为97.58%,96.12%,96.56%,100.25%,96.63%,99.80%,106.73%,RSD分别为1.11%,1.29%,2.43%,1.09%,0.89%,1.26%,4.48%(n=9)。23批样品中7种元素杂质含量均低于控制阈值。结论该方法操作简便、精密度好、结果准确,可用于枸橼酸三乙酯中痕量元素杂质的含量测定。

Objective To establish an inductively-coupled plasma-mass spectrometry(ICP-MS)method for the determination of residual quantity of seven elemental impurities[cadmium(Cd),lead(Pb),arsenic(As),mercury(Hg),cobalt(Co),vanadium(V),and nickel(Ni)]in triethyl citrate.Methods The online internal standard method was used,with helium as the carrier gas and HMI-8 plasma mode.The flow rates of the carrier gas,atomization gas,and auxiliary gas were all 0.8 L/min,the flow rate of plasma gas was 15.0 L/min,the speed of nebulizer pum was 0.10 r/min,and the temperature of atomizer chamber was 2℃.Results The linear ranges of V,Co,Ni,As,Cd,and Pb elements were 0-20.0 ng/mL,and the linear range of Hg element was 0-5.0 ng/mL(r≥0.9995,n=7).The RSD of precision test result was lower than 3%(n=6).The recovery rates of V,Co,Ni,As,Cd,Pb and Hg were 97.58%,96.12%,96.56%,100.25%,96.63%,99.80%,and 106.73%,with RSDs of 1.11%,1.29%,2.43%,1.09%,0.89%,1.26%,and 4.48%(n=9),respectively.The content of seven elemental impurities in 23 batches of samples was lower than the control threshold.Conclusion This method is simple,has good precision,and accurate results,which can be used for the determination of trace elemental impurities in triethyl citrate.