变色酸分光光度法测定食用酒精中微量甲醛的条件研究

Measuring Small Content of Formaldehyde in Edible Alcohol by Chromotropic acid Spectrophotometry

研究了用变色酸-磷酸-H2O2显色体系测定食用酒精中的甲醛含量的方法.通过实验确定出此法的测定波长为575 nm,在沸水浴中,显色时间为30 min时,能收到最好的显色效果.测定、统计、回归,得到甲醛的标准曲线:y=0.642x-0.003 5.进行了大量的干扰试验,研究表明:除当苯酚含量大于等于甲醛浓度20倍的时候,对测定有干扰,其余测定的物质均无干扰。该方法的检出限为:0.02ug/ml.实验证明此方法可以用于食用酒精中甲醛的测定.

The method of measuring the small content formaldehyde in edible alcohol by chromotropic acidphosphor-H2O2 system was studied. First, measuring mechanism was discussed. Then experiment showed that its wavelength is determined to be 575 nm, when conducted in the boiling water, its time duration is 30 minutes for the best result. The standard curve of formaldehyde was determined by the methods of measurement, statistics and regression to be y = 0. 642 x - 0. 0035. At the same time, a number of disturbing experiments were conductedwith satisfactory results. The check limit of this method was 0. 02ug/mL. It is proved that this method can be used in measuring formaldehyde in edible alcohol.