荧光分光光度法测定生活用纸制品中的荧光增白剂

Determination of fluorescent whitening agents in household paper by fluorescence spectrophotometry

通过对三种常用二苯乙烯型荧光增白剂VBL、BA、CXT荧光光谱和标准曲线的研究,建立了以VBL为标准物质检测生活用纸中荧光增白剂的定量方法。该方法激发波长为345 nm,发射波长为430 nm;定量标准曲线为y(μg/mL)=0.001 7x-0.018 7,在0～1.0μg/mL范围内线性相关性R2=0.999 2;方法检出限4μg/g,定量限10μg/g,平均加标回收率为95.3%,可满足检测要求。对pH和实验用水纯度对VBL稳定性的影响进行了初步探讨,发现实验中应使用纯度高的水和在中性或弱碱性的pH条件下,结果比较稳定。

Comprehensive method for determining fluorescent whitening agent in household paper was studied. Through studying the fluorescence spectra and calibration curves of three stilbene-based fluorescent whitening agents （FWAs）, VBL, BA and CXT, one quantitative method for determining FWAs in household paper was developed with VBL as the standard of FWAs. The excitation and emission wavelengths in the measurement are 345 nm, 430nm respectively. When the concentrations of FWAs are from 0 to 1.0 μg/mL, they have a linear relationship with the emitted fluorescence intensity. In this interval, the calibration curve is y （p.g/mL）=0.001 7x- 0.0187, and R2 is 0.9992, the limits of detection and quantification are 4μg/g and 10μg/g respectively, and the average percentage of recovery is 95.3%, which meet the measuring requirements. The influence on the stability of VBL was investigated taking the pH and the purity of water used for experiments into concerned, and it was found that the stable results could be obtained in the conditions of high purity water, neutral pH or weak alkaline.