分光光度法测定食品中的铝

Determination of aluminum in foodstuffs through spectrophotometry

采用灰化法使铝盐失水,生成氧化铝,用酸提取,通过分光光度法,在乙酸-乙酸钠缓冲溶液中,铝与铬天青S生成紫红色络合物,进行定量分析.该法的回收率达87%-107%.r=0.999 9,显色稳定.该法无论在样品处理上,还是后期比色,都明显优于《GB/T5009.182-2003面制食品中铝的测定》.

Aluminum in foods mainly derives from the additives in them. Aluminum compounds contained in the additives, through the ashing method, would lose water and turn into alumina, which is to he extracted by acid and through spectrophotometry would, together with chrome azurol S, form purple-red complex compounds in the glacialacetic acid-sodium acetate fluids, and so can be determined. Through the method, the recovery rate reaches 87 to 107 percent, r = 0. 999 1, and the color development is stable, compared with GB/T5009. 182-2003 ＂Determination of Aluminum in Flour-made Foodstuffs＂. Therefore, spectrophotometry is much superior, whether in handling the samples or in comparing color in later period, to the National Standard Method, which is difficult to gauge perchloric acid accurately and so to the determination of color comparison.