Cabanis M T, Cassanas G, Cabanis J C, Brun S
Laboratory of Analytical Chemistry and Industrial Physics, Faculty of Pharmacy, Montpellier, France.
J Assoc Off Anal Chem. 1988 Sep-Oct;71(5):1033-7.
We compared 4 digestion procedures, namely, sulfuric-nitric acid in an open flask, nitric acid under pressure, sulfuric-nitric acid with refluxing, and nitric-hydrochloric-peroxide with refluxing, for the determination of cadmium by flameless atomic absorption spectrophotometry in 3 foodstuffs: rice, beef, and cream cheese. The foodstuffs were homogenized and divided into several batches for analysis. The results were evaluated using a 2-way cross analysis of variance. The study revealed that the digestion procedure was a highly significant factor (P less than 10(-4] in the analysis of the 3 foods; whereas the nature of the foodstuffs was not significant for rice and meat and only slightly significant (P less than 10(-2] for cream cheese. When the foodstuffs were spiked with a known amount of cadmium, we observed a loss of the metal when the sulfuric-nitric acid procedure in an open flask and the nitric-hydrochloric-peroxide digestion procedure were used. Taken together, the results of the present study indicate that the choice of the reagents used for digestion of foodstuffs is a crucial factor for cadmium determination by flameless atomic absorption spectrophotometry.
我们比较了4种消化程序，即敞口烧瓶中的硫酸-硝酸法、加压硝酸法、回流硫酸-硝酸法以及回流硝酸-盐酸-过氧化氢法，以通过无火焰原子吸收分光光度法测定大米、牛肉和奶油芝士这3种食品中的镉。将食品均质化并分成几批进行分析。结果采用双向交叉方差分析进行评估。研究表明，消化程序是分析这3种食品时的一个极显著因素（P小于10^(-4)）；而食品的性质对大米和肉类不显著，对奶油芝士仅略有显著（P小于10^(-2)）。当食品中加入已知量的镉时，我们观察到使用敞口烧瓶中的硫酸-硝酸法和硝酸-盐酸-过氧化氢消化程序时会出现金属损失。综上所述，本研究结果表明，用于食品消化的试剂选择是通过无火焰原子吸收分光光度法测定镉的关键因素。
