植物油料与植物油中砷含量检测的研究

Determination of arsenic in plant oil seeds and their oils

采集砷矿产资源区、一般地区和进口的植物油料并对其压榨取油,分别采用压力消解-氢化物原子吸收光谱法及溶剂萃取-氢化物原子吸收光谱法测定植物油料和对应植物油中的砷含量.结果显示,植物油料压力消解前处理的最佳条件为：取样量0.500 0 g,消解液第1次添加量为HNO34 mL、H2O2 1 mL,第2次添加量为HNO3 4 mL、H2O2 3 mL,消解初温90℃,消解1h,消解终温160℃,消解5h;在最佳条件下可将植物油料样品消解完全.所测15个植物油料样品及8个植物油样品的砷含量均未超出国家限量标准;砷矿产资源区植物油料及植物油中的砷含量略高于一般地区;植物油料与对应植物油中的砷含量基本呈正相关;溶剂萃取-氢化物原子吸收光谱法测定植物油中砷含量的加标回收率为93％ ～ 110％,相对标准偏差小于10.9％.

The contents of arsenic in plant oil seeds and their oils from arsenic mineral resource areas, common areas and import by pressure digestion -hydride generation atomic absorption spectrometry （HG- AAS） and solvent extraction - HG - AAS were determined. The results indicated that the optimal pressure digestion pretreatments of plant oil seeds were as follows： sample amount 0. 500 0 g, adding 4 mL of HNO3 and 1 mL of H20z as digestion solution for the first time, adding 4 mL of HNO3 and 3 mL of H202 as digestion solution for the second time, initial digestion temperature 90 ℃, digestion time 1 h, final digestion temperature 160 ℃, digestion time 5 h. Under these conditions, the plant oil seeds completely digested. The arsenic contents of the fifteen plant oil seeds and eight plant oils samples were within the limitation of national standard; the arsenic contents of plant oil seeds and their oils in arsenic mineral resource areas were slightly higher than that in common areas; the correlation of the contents of arsenic in plant oil seeds and their oils were positive ; the recovery rate of arsenic in plant oils determined by solvent extraction -HG- AAS method was in the range of 93% -110% ,and the relative standard deviation was lower than 10.9%.