硝酸镁/乙醇溶液浸泡后灰化消解-原子荧光光谱法测定海鱼粉中总砷

Determination of total arsenic in sea fish powder by ashing digestion-atomic fluorescent spectrometry after being soaked in magnesium nitrate/ethanol solution

[目的]建立硝酸镁/乙醇溶液浸泡后灰化消解-原子荧光光谱法测定海鱼粉中总砷的检测方法。[方法]样品用硝酸镁/乙醇溶液浸泡过夜后,再进行灰化消解;消解液经过预还原,用原子荧光光度计测定,同时采用海鱼粉质控样品进行方法验证。[结果]砷标准曲线范围0.00~10.00μg/L;相关系数≥0.999 0;检出限为0.05μg/L;加标回收率95.4%~100.4%,相对标准偏差≤4.83%;本法6次测定海鱼粉质控样品结果均在指定值的容许范围内[指定值(780±80)μg/kg],均值为818μg/kg,相对标准偏差3.42%。[结论]用硝酸镁/乙醇溶液浸泡后灰化消解-原子荧光法测定海鱼粉中总砷,操作安全,稳定性好,准确度高,尤其适用于动物类海产品中总砷的测定。

[ Objective ] To establish a method of ashing digestion-atomic fluorescent spectrometry （AFS） for determination of total arsenic in aquatic animal products after being soaked in magnesium nitrate/ethanol solution. [ Methods ] Samples were ashing digested after being soaked in magnesium nitrate/ethanol solution for a whole night. Then, the digestion solution was pre-reduced and determined by AFS. The result was verified using sea fish powder standard sample. [ Results ] In terms of the proposed method, the standard curve range was 0.00-10.00 μg/L; the correlation coefficient was ≥ 0.9990; the detection limit was 0.05 μg/L The recoveries of the method were 95.4%-100.4%, with relative standard deviation ≤ 4.83%. All six verified values of sea fish powder standard sample were within the permitted range of （780 ± 80） μg/kg, with a mean value of 818 μg/kg and a relative standard deviation of 3.42%. [ Conclusion ] The method of ashing digestion-atomic fluorescent spectrometry after being soaked in magnesium nitrate/ethanol solution is safe, stable, and accurate for the determination of total arsenic in animal seafood.