黄酒中尿素的测定

Determination of Urea in Rice Wine

二乙酰-肟分光光度法是测定黄酒等样品中尿素含量的一种快速、灵敏、简便的方法。样品中的尿素与显色试剂在沸水浴中发色10～15min后比色测定,显色的线性范围在0～9μg尿素之间。测得的结果中包含了瓜氨酸的含量。样品中酒精和葡萄糖的存在不干扰测定。以标准加入法进行定量,从而使该方法的回收率和重现性大大提高,可满足一般痕量分析的要求。

A rapid,sensitive and simple method was developed for the measurement of urea in rice wine. Urea was colorimetrically determined with diacetyl monoxide and thiosmicarbazide in the present of sulfuric acid,phosphoric acid and ferric chloride. Color reaction was hold in boiling water for 10-15 min. The analysis gave good linear respones to 0-9μg urea. Citrulline also gave positive result. Glucose and ethanol did not interfere with the reaction. The recovery and repeatability were greatly improved by standard addition calibrating technique.