基于偏最小二乘法的氨基甲酸甲酯和尿素含量的同时测定

开发了一种同时测定氨基甲酸甲酯与尿素混合物的方法。用紫外可见光分光光度计测定混合物的吸光度,采用偏最小二乘法模型对吸光度进行校正,并预测试样各组分的浓度。考察了测定条件对测定结果的影响。得到的最优测定条件为:显色剂用量20mL,盐酸用量12mL,显色时间15min,试剂加入顺序盐酸→显示剂→试样,测定波长范围410～445nm。计算结果与实际值的误差很小,平均回收率接近于100%,相对均方根偏差小于4%。该方法可不经分离同时测定各组分的浓度,准确度高,过程简单,运算快速。

Simultaneous Determination of Methyl Carbamate and Urea Based on Partial Least-Squares Method

A new method was proposed for simultaneous determining of methyl carbamate and urea in mixture.UV-Vis spectrophotometer was used to determine absorbency of samples.Partial Least-Squares(PLS)model was applied to correct absorbency and predict concentrations of each component.Some operation conditions had been investigated.Optimal conditions were:dosage of chromogenic reagent 12 mL,dosage of hydrochloric acid 12 mL,and chromogenic reaction time 15 min.The adding sequence of reagents to volumetric bottle was hydrochloric acid→chromogenic reagent→sample.The determining range of wavelength was 410—445 nm.The error between calculated and actual value was very small;average recovery of each sample stood at 97.5%—107.3% range;The deviation of relative mean square root was smaller than 4%.The whole investigation indicated that concentration of each component in mixture could be obtained simultaneously by this method without previous separation.This analytical method provided advantages of high-accuracy,simplicity,high-speed and can also be applied to other similar systems.