紫外-可见光谱法快速测定乙酸乙酯含量

为探讨一种快速有效的乙酸乙酯(EA)含量测定方法,以确定和优化乙酸乙酯的制备工艺,提出了一种基于紫外-可见光谱法快速测定乙酸乙酯含量的方法,并通过丁酮和过氧化氢反应液验证该方法的精确度和准确性.结果表明:乙酸乙酯在与盐酸羟胺乙醇及FeCl_3进行显色反应后,生成的洋红色络合物在530nm处具有最大吸收峰,通过双波长分光光度法建立该洋红色物质在530nm及800nm处的吸光值差值与乙酸乙酯浓度之间的线性关系,可定量测出乙酸乙酯的含量;此方法简单、快速,且在FeCl_3/EA摩尔比不小于1.1、沸水浴温度为100℃、沸水浴时间为40s、显色后物质在60s内完成测定时效果较好,在丁酮和过氧化氢反应液中其测定相对偏差为1.79%,回收率为95.5%～105.0%.

Rapid Determination of Ethyl Acetate Content via UV-Vis Spectroscopy

A rapid and effective determination method of ethyl acetate (EA) content is helpful for the determination and optimization of EA production technology. This paper proposes a rapid determination method of EA content based on UV-Vis spectroscopy, and verifies the accuracy of the method using a sample derived from the reaction of butanone and hydrogen peroxide. It is found that (1) the carmine complex derived from the color reaction of EA, hydroxylamine-HCl ethanol and FeCl_3 is of the maximum absorption at 530nm;(2) by establishing the linear relationship between the absorbance difference at 530nm and 800nm and the EA content via the dual-wavelength spectrophotometry, EA content can be successfully quantified;(3) this simple and low-cost method is of reasonably good precision when the color reaction is performed at a FeCl_3/EA molar ratio of not less than 1.1 in a 100℃ boiling-water bath for 40s, and when the detection of UV spectroscopy is finished within 60s;and (4) the content determination error and recovery of EA derived from the reaction of butanone and hydrogen peroxide reach 1.79% and 95.5%～105.0%, respectively.