双份饭中铁、锌、钙的火焰原子吸收测定法

Determination of Fe,Zn and Ca in Duplicate Food Portions by Flame Atomic Absorption Spectrometry

目的建立火焰原子吸收法测定双份饭中铁、锌、钙的方法。方法样品经馄合酸(硝酸+高氯酸=4+1)消解后,钙用20g/L的氧化镧溶液定容,铁、锌用纯水定容后直接测定。结果铁浓度在0.20～2.00μg/ml范围时,相关系数为0.9996,加标回收率为96.5%～102.7%,检出限(3σ)0.006μg/ml;锌浓度在0.10～1.50μg/ml范围时,相关系数为0.9997,加标同收率为95.0%～101.5%,检出限(3σ)0.004μg/ml;钙浓度在1.00～10.00μg/ml范同时,相关系数为0.9994,加标回收率为96.8%～103.6%,检出限(3σ)0.008μg/ml。结论该方法简便快捷,测定结果准确可靠,适合于双份饭分析。

[Objective]To establish the method of determining Fe,Zn and Ca in duplicate food portions by flame atomic absorption spectrometry.[Methods]The samples were digested with the mixed acid of V（HNO3）＋V（HClO4）=4＋I,then Ca was diluted with lanthanum oxide of 20 g/L.Fe and Zn were diluted with pure water before determination.[Results]The concentration of Fe ranged from 0.20～2.00 μg/ml,the correlation coefficient was 0.9996,the recovery of standard addition was 96.5%～102.7% and the detection limit（3 σ） was 0.006 μg/ml.When the concentration of Zn ranged from 0.10～1.50μg/ml,the correlation coefficient was 0.9997,the recovery of standard addition was 95.0%～101.5% and the detection limit（3 σ） was 0.004 μg/mL.At the concentration range of 1.00～10.00 μg/ml,the correlation coefficient was 0.9994,the recovery of standard addition was 96.8%～103.6% and the detection limit（3 σ） was 0.008 μg/mL for Ca.[Conclusion]The method is simple,rapid,reliable and suitable for determination of duplicate food portions.