关键词: EBT-1, 2-丙二醇, 分光光度法, 食品, 镁含量

Abstract: A new spectrophotometric method for determining magnesium content in foodstuffs with EBT-1,2-propanediol as color reagent was developed. After being digested with HNO3-HClO4,samples were added with sodium tungstate to eliminate interference of ca2+ and added with triethanolamine-tetraethylenepentamine to mask Al3+ and Fe3+ etc. In ammonia buffer solution at pH 10.5,Mg2+ and EBT form a claret-red complex,which can be dissolved in water and has a maximum absorbance at 520 nm wavelength. The method is successfully applied for determination of magnesium in different foodstuffs with relative standard deviations of less than 1.0%,relative deviation of less than 2.0% and recoveries of spiked standard of 95.4%～102.4%. The results are consistent with those by China national standard method. The improved method is easily operated with the characteristics of fast determination,high accuracy and little disturbance.

Key words: EBT-1,2-propanediol, spectrophotometry, foodstuff, magnesium content