火焰原子吸收分光光度法测定食物中血红素铁

Determination of heme iron in food by flame atomic absorption spectrophotometry

目的为研究膳食血红素铁的摄入与缺铁性贫血的关系,建立食物血红素铁的火焰原子吸收分光光度法。方法食物中的血红素铁用酸性丙酮(丙酮∶水∶盐酸=80∶10∶10,V/V)提取,提取液经硝酸和高氯酸(4∶1,V/V)消化后,用火焰原子吸收分光光度法(FAAS)测定铁含量。结果测量条件:狭缝宽度为0.4 nm,灯电流为4 m A,空气乙炔燃烧率为15/2,燃烧器高度为7.5 nm。线性方程A=0.037 5C+0.005 1,相关系数为0.999 1,相对标准偏差(RSD)<0.86%;加标回收率为90.41%~101.81%;检出限为0.016μg/ml。所测猪肝粉样品中总铁平均含量为28.94 mg/100 g,;血红素铁平均含量为19.63 mg/100 g;非血红素铁含量为6.91 mg/100 g。血红素铁占总铁的67.82%。结论该方法操作方便,稳定性好,重现性好,可用于食物中血红素铁的分析。

Objective In order to explore the relationship between iron deficiency anemia and heme iron intake from diet, to establish a determination method of heme iron in food by flame atomic absorption spectrophotometry. Methods Heme iron in food was extracted with acid acetone （ acetone ： H20 ： HC1 = 80 ： 10 ： 10, V/V）, after the extracts were digested by a concen- trated nitric acid and perchlorie acid （4 ： 1, V/V）, the contents of heme iron was measured by flame atomic absorption spectro- photometric method（FAAS）. Results The measure condition ： the slit width was 0.4 nm, lamp was 4 mA, air - acetylene combustion ration was 15/2, burner height was 7.5 nm. Under this condition, the linear equation was A = O. 037 5C ＋ O. 005 1, correlation coefficient（r） was 0. 999 1, the relative standard deviation（RSD） was 〈0.86%. The addition standard recovery was within 90.41% -101.81%. The detection limit of heme iron was 0. 016 μg/ml. The average content of total iron in the pork liver powder sample was 28.94 rag/100 g, the average content of heine iron in the pork liver powder sample was 19.63 mg/lO0 g; and the content of non- heme iron in the pork liver powder was 6.91 mg/100 g. Heine iron accounted for 6%. 82% of total iron. Conclusion This method has convenient operation, good stability and good reproducibility. The method could be used to analyze heine iron in food.