建立了内标表面增强拉曼光谱测定水性有机涂料中石墨含量的方法。以聚丙烯酸丁酯乳液为标准基材, 加入不同体积的石墨悬浮液, 并以硫氰酸钾(KSCN)为内标, 加入纳米银溶胶后制成不同石墨含量的工作样品, 采集拉曼光谱。1584 cm-1为石墨的特征峰(G峰), 2124 cm-1为内标的特征峰, 以两峰面积之比制作标准曲线, 线性关系良好, 5000目石墨和200目石墨的相关系数r2分别为0.9994和0.9934。对于5000目石墨, 最低检出限(LOD)为0.12%, 方法精密度为6.99%, 聚丙烯酸丁酯基材和聚醋酸乙烯酯基材的加样回收率分别为79.49%和76.29%, 均满足检测要求。该方法简便、快速、准确, 可作为含碳材料成分的水性有机涂料的质量控制手段。

The surface-enhanced Raman spectroscopy method with internal standard was established to determine graphite in water-borne organic paints.The working samples, which were tested by Raman spectroscopy, were prepared by adding graphite into poly(butyl acrylate) latex substrate, followed by pipeting potassium thiocyanate(KSCN) as internal standard and silver nano-particles(Ag NP).Since 1584 cm-1 was recognized as graphite’s G peak while 2124 cm-1 as KSCN’s peak, standard curve was made by calculating the ratio of the two peaks, which exhibited good linearity with r2=0.9994 and 0.9934 for 5000 mesh graphite and 200 mesh graphite, respectively.For 5000 mesh graphite, the limit of detection(LOD)is 0.12%, and precision was 6.99%.The spiked recovery of poly(butyl acrylate) and polyvinyl acetate substrates was 79.49% and 76.29%, respectively.All the indices met the testing requirements.This method was convenient, rapid and accurate, and could be used as the quality control method for water-borne organic paints with carbon materials.