荧光分光光度法测定学生作业用纸中荧光增白剂的含量

Determination of Fluorescent Whitening Agents in the Paper for Students' Notebook by Fluorescence Spectrophotometry

关键词:  荧光分光光度法  荧光增白剂  学生作业用纸

Key Words:fluorescence spectrophotometry  fluorescent whitening agents  the paper for students' notebook

摘要:以荧光增白剂VBL为标准物质建立了荧光分光光度法测定学生作业用纸中荧光增白剂含量的方法。该方法的荧光激发波长为350 nm、发射波长为430 nm，VBL浓度在0~1.0 μg/mL范围内与荧光强度呈线性关系，线性方程为F=448.96x+8.4649，相关系数R²=0.9986。分别探究了萃取温度、乙醇浓度及其用量、超声时间和萃取次数等因素对学生作业用纸萃取滤液中荧光增白剂浓度的影响。最佳的萃取条件为萃取温度60℃，萃取剂为50%乙醇，萃取剂与纸样质量比为300∶1 (mL∶g)，超声时间60 min，萃取次数为2次。并对几种学生作业用纸中的荧光增白剂进行了萃取和定量分析，该方法具有简便、灵敏和准确的特点，能够满足检测需求。

Abstract:A fluorescence photometric method for the determination of fluorescent whitening agents （FWAs） in the paper for students' note-book was established by using VBL as the standard. The fluorescence excitation wavelength of this method was 350 nm and the emission wavelength was 430 nm. When the concentration of VBL was in the range of 0 to 1.0 μg/mL， it had a linear relationship with the emitted fluorescence intensity. The linear equation was F=448.96x+8.4649， R²=0.9986.The effects of extraction temperature， concentration and dosage of extractant ethanol，ultrasonic extraction time and extraction times on the concentration of FWAs in the extract filtrate of paper were investigated.The optimum extraction conditions were extraction temperature of 60℃， extractant of 50% ethanol， mass ratio of extractant to paper sample was 300 ∶ 1（mL ∶ g） ， ultrasonic time of 60 min， extraction times of 2 times. This method could be used to extract and quantify FWAs in the paper for students' notebook， which was simple， sensitive and accurate， and could meet the requirement of detection.