中红外光谱法测定车用尿素含量

Determination of Urea Used for Motor Vehicle Content by Mid-infrared Spectroscopy

建立中红外光谱法测定车用尿素含量。在预先设定好的光谱条件下,直接进样,操作简单快速,没有任何前处理过程。以含量与对应的吸收峰强度建立校正模型。结果显示,车用尿素含量在25%(m/m)^40%(m/m)范围内,在1460cm^(-1)和1157cm^(-1)波数呈现良好的线性,校正模型相关系数均大于0.999,样品重复测定7次,相对标准偏差(RSD)在0.38%^0.76%之间,与相对应国标方法进行比对试验,此方法的准确性满足国标的要求。

A method for the determination of urea used for motor vehicle content by mid-infrared spectroscopy was developed.Under the presetting conditions,the sample was injected directly,the operation was simple while there was no pretreatment process.The calibration model was establis hed based on the content and the corresponding absorption peak intensity。The results showed that the content of aqueous urea solution was linear in the range of 25%(m/m)~40%(m/m),and showed good linearity in 1460cm^(-1) and 1157cm^(-1) wavenumbers.The correlation coefficients of calibration model were all greater than 0.999.The samples were repeated for 7 times,and the relative standard deviation (RSD) was between 0.38% and 0.76%.The accuracy of this method met the requirements of national standard.