电感耦合等离子体质谱仪测定生物柴油中微量元素的微波消解工艺研究

STUDY ON MICROWAVE-ASSISTED DIGESTION OF BIODIESEL FOR DETERMINATION OF TRACE ELEMENTS BY ICP-MS

采用稀硝酸和过氧化氢溶液对生物柴油进行微波消解,并利用电感耦合等离子体质谱仪(ICP-MS)对消解后的生物柴油进行微量元素测定,研究硝酸浓度和过氧化氢添加量对生物柴油消解效果的影响,并综合剩余碳含量和剩余酸度作为评价指标。结果表明:当采用6.0mL浓度为6.0mol/L的硝酸和2.5mL H_2O_2的混合溶液对0.6g生物柴油进行微波消解后,剩余碳含量和剩余酸度分别为5.3%和6.4%;ICP-MS测定Ba,Mn,Mo,Cr,Cu,Ni,Pb,Sr,V,Zn等分析物的加标回收率为94.2%~107.4%,相对标准偏差小于4.33%。

A microwave-assisted digestion using diluted nitric acid and hydrogen peroxide as auxiliary agent was explored to determine trace elements in biodiesel by inductively coupled plasma mass spectrometry（ICP-MS）.The effect of nitric acid concentration and volume of hydrogen peroxide on biodiesel digestion was investigated,using residual carbon content and residual acidity in final solutions as evaluation index.Results showed that 0.6g of biodiesel was almost completely digested under the optimal conditions：6mL nitric acid（6mol·L^-1）and 2.5 mL hydrogen peroxide.The residual carbon content and the residual acidity in digests were lower than 5.3%and 6.4%,respectively.After sample digested,Ba,Cr,Cu,Mn,Mo,Ni,Pb,Sr,V and Zn were determined by ICP-MS and the recovery rate was in the range of 94.2%to 107.4%.All RSDs were less than 4.33%.