在现行GB/T 27741-2018的“纸和纸板可迁移性荧光增白剂的测定”对纸制品进行萃取时, 其中的残余木素会部分析出, 对可迁移性荧光增白剂含量的光谱检测造成了干扰。 据此, 提出了一种旨在消除未知光谱干扰影响的、 基于紫外光谱等吸收偏离校正的三波长法检测纸制品中荧光增白剂的新方法。 因为未知干扰在321～374 nm处光谱近似为一条相似斜率的曲线, 导致荧光增白剂最大吸收峰以及所对应的两个等吸收点的吸光度发生偏差。 因此可通过三波长法和数学计算扣除未知干扰在最大吸收波长处对荧光增白剂吸光度检测的干扰, 从而得到可迁移性荧光增白剂在最大吸收波长处的准确吸光度, 以实现对可迁移性荧光增白剂的准确定量检测。 结果表明: 该方法的重复性检测的相对标准偏差为3.7%; 定量检测限为19 mg·kg-1; 回收率在99.1%~107%之间。 与现行可迁移性荧光增白剂检测方法相比, 由于该方法具有分析简便、 仪器易操作等优点, 因此更适合于对各种纸制品(尤其是印刷品)中的可迁移荧光增白剂含量的快速、 准确检测, 并可以为纸制品质量安全的生产控制和市场监督提供保证。

In the current GB/T 27741-2018 “Paper and board-Determination of migratable fluorescent whitening agents (FWAs)” when extracting paper products, the residual lignin leached from cellulose which would interferespectral detection of FWAs. In this paper reported a tri-wavelength UV spectroscopy method for the determination of FWAs in paper products. By figuring out the isosbestic points shift at the range of 321～374 nm, the spectral interference of other species in the extraction solution on the FWAs measurement can be mathematically corrected. The results showed that the present method has the relative standard deviation of 3.7% and recovery of 99.1 and 107%, with the limit of the quantity of 19 mg·kg-1. Compared with the current FWAs detection method, the method has the advantages of simple analysis, easy operation of the instrument, and the like. Therefore, it is suitable for rapid and accurate determination of the content of migratable FWAs in various paper products, especially printing related materials and can guarantee the production quality control and market supervision of paper products.