紫外分光光度法同时测定乙醛和乙二醛

利用醛与水合肼反应生成腙,采用紫外分光光度法可间接分析乙醛和乙二醛的含量。成腙条件为n(醛基)?n(肼)≤1?2,pH值为5.5(用醋酸-醋酸钠缓冲溶液调节),温度为60℃,时间为50 min,检测波长为230 nm和280 nm。测得230 nm和280 nm处的相对标准偏差分别为1.50%和1.89%,乙醛和乙二醛的平均回收率分别约为103.53%和97.14%。该方法可用于乙醛硝酸氧化法制备乙二醛中乙醛和乙二醛含量的监测。

UV-spectrophotometric determination of both acetaldehyde and oxalaldehyde

Based on the UV-spectrophotometry of hydrazone which was obtained from aldehyde and hydrazine hydrate, the determination of acetaldehyde and oxalaldehyde at one time was proposed. The reaction was carried out at 60 ℃ within 50 minutess and the tool ratio of aldehyde group and hydrazine is not more than 1 ： 2 and pH = 5. 5 （regulated by CH3COOH- CH3COONa buffer）. The detect wavelengths are 230 nm and 280 nm. The relative standard deviations under the wavelengths are 1.50% and 1.89% separately. The recoveries for acetaldehyde and oxalaldehyde are about 103.53% and 97.14% respectively. This method can be used to determine simultaneously the contents of acetaldehyde and oxalaldehyde, when preparing oxalaldehyde from the reaction of acetaldehyde with nitric acid.