【摘要】 作者用氨气敏电极法测定了食品中蛋白质含量,为了克服测定过程中析出氢氧化铜沉淀而在消化液中加入EDTA-2Na,使测定顺利进行。此法操作简便快速,结果准确可靠。与凯氏定氮法的测定结果比较,差异无显著性(P>0.05),方法重现性良好,变异系数为1.6％;平均回收率为99.17±6.73％。更多还原

【Abstract】 The determination of proteins in foodby ammonia gas sensor electrode is reported.The sample is digested with concentratedsulphuric acid till a clear solution is obtain-ed.The excess acid is evaporated and thenthe solution is transferred to an 100 ml volumetric flask and diluted to the mark.To the diluted solution a certain amount ofNa₂-EDTA solution in sodium hydroxide isadded.This prevents the precipitation ofsome metal hydroxides.The ammoniaformed is determined by an ammonia gassensor electrode. The reliability of the method is confirmedby comparison with the Kjeldahl method（P>0.05）, the coefficient of variation andpercentage of recovery by the method being1.6% and 99.17±6.73% respectively.更多还原