电感耦合等离子体发射光谱测定食用植物油中的重金属元素Determination of heavy metal elements in edible vegetable oils by inductively coupled plasma optical emission spectrometry

研究快速准确测定食用植物油中重金属元素的方法。采用微波消解对食用植物油样品进行预处理，在多模式进样系统（MSIS）的双重模式下，采用电感耦合等离子体发射光谱（ICP-OES）测定其中可形成蒸气重金属元素As、Sb、Hg和不可形成蒸气重金属元素Ni、Cd、Pb的含量。选择盐酸对样品进行酸化并还原氧化态元素，通过在线加入L-半胱氨酸/酒石酸提高可形成蒸气元素的蒸气发生效率，利用快速自动曲线拟合技术（FACT）消除光谱干扰。方法的检出限（LOD）为0.63~20.60 μg/kg，加标回收率为97.0%~104%，相对标准偏差（RSD）为1.5%~2.6%。该方法在分析可形成蒸气元素和不可形成蒸气元素时无需切换不同进样系统，能满足食用植物油中微量重金属元素的高通量分析需要。 A rapid and accurate method for the determination of heavy metals in edible vegetable oils was investigated. Edible vegetable oils were pretreated with microwave digestion. In the dual mode of multimode sample introduction system (MSIS), the contents of vapor forming heavy metal elements As, Sb and Hg and non-vapor forming heavy metal elements Ni, Cd and Pb were determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Hydrochloric acid was selected to acidify the sample and reduce the oxidized elements in the sample. L-cysteine/tartaric acid was added online to improve the vapor generation efficiency. Fast automatic curve fitting technology (FACT) was used to eliminate spectral interference. The method detection limit (LOD) was 0.63-20.60 μg/kg, the recovery rate was 97.0%-104%, and the relative standard deviation (RSD) was 1.5%-2.6%. The method does not need to switch between different sampling systems when analyzing vapor forming elements and non-vapor forming elements, which can meet the needs of high throughput analysis of trace heavy metal elements in edible vegetable oils.