同时测定秋葵籽油中8种金属元素的ICP-MS法的建立

Establishment of ICP-MS method for simultaneous determination of 8 metal elements in okra seed oil

建立了微波消解-电感耦合等离子体质谱仪测定秋葵籽油中Pb、As、Zn、Mn、Cu、Fe、Ca、Mg的方法。样品经微波消解后,采用电感耦合等离子体质谱法(ICP-MS)进行测定,载气为氩气,碰撞气为氦气,等离子体气流速为14.5 L/min,辅助气流速为1.2 L/min,射频功率为1300 W,雾化器流量为0.9 L/min,采样深度为8.0 mm,分析时间为0.1 s,样品提升量为1.0 mL/min。考察了该方法的检出限、线性范围、加标回收率、重复性等指标,在此基础之上,比较了4种不同制备工艺秋葵籽油中8种元素的含量。结果表明:这8种金属元素在各自线性范围内线性关系良好(r≥0.9988),检出限为0.016~0.881 mg·kg-1,重复性(RSD)为1.8%~4.6%,加标回收率为85.8%~105.2%;8种金属元素的含量与秋葵籽油的制备工艺不存在相关性。该方法具有快速简便、灵敏度高、准确性好等特点,适用于秋葵籽油中8种金属元素含量的测定。

A method was developed to determine Pb,As,Zn,Mn,Cu,Fe,Ca,and Mg in okra seed oil using microwave digestion and ICP-MS.The sample was determined by ICP-MS after microwave digestion.The carrier gas was argon and the collision gas was helium;the plasma gas flow rate was 14.5 L/min and the auxiliary gas flow rate was 1.2 L/min;the RF power was 1300 W and the atomizer flow rate was 0.9 L/min;the sampling depth was 8.0 mm,analysis time was 0.1 s,and the sample lifting amount was 1.0 mL/min.The detection limit,linear range,standard recovery and method repeatability were investigated.On this basis,the content of eight metal elements in okra seed oil under four different preparation processes were detected and compared.The results showed that the eight metal elements had good linear relationship in their respecitve linear range(r≥0.9988).The limit of detection was 0.016-0.881 mg·kg-1.The repeatability was 1.8%-4.6%.The average recovery rate was 85.8%-105.2%.The results showed that there was no correlation between the content of the eight metal elements and different preparation processes of okra seed oil.The method has been proven to be simple,highly sensitive and accurate,which is suitable for the determination of the eight metal elements in okra seed oil.