微波消解-石墨炉原子吸收光谱法测定纳米二氧化钛中痕量砷

建立了微波消解-石墨炉原子吸收光谱法（GF-AAS）测定纳米二氧化钛中痕量杂质元素砷的分析方法。采用由一定浓度和比例的氢氟酸、硝酸组成的混合试剂,结合应用高压密闭微波加热技术快速完全消解纳米二氧化钛样品,优选了最佳微波加热控制程序,不仅解决了二氧化钛难消解和待测元素砷高温消解过程中易挥发损失等难点,而且检测溶液酸度低,避免对GF-AAS石墨管的侵蚀。并且,通过基体效应影响实验,优化选择了石墨管类型、石墨炉升温原子化控制程序以及原子吸收光谱仪检测参数,消除热稳定性强的二氧化钛基体对测定易挥发痕量元素砷的影响。方法检出限为0.02μg/L,加标回收率为93.0%~106.0%,相对标准偏差9.4%,与ICP-MS检测方法结果对照一致。

Microwave Digestion-Graphite Furnace Atomic Absorption Spectrometry Determination of Trace Arsenic in Nano-Titanium Dioxide

The analysis method that the microwave digestion - graphite furnace atomic absorption spectrometry (GF-AAS) determination of trace impurity element arsenic in the nano-titanium dioxide has been built. It uses a mixture digestion reagent which is composed of a certain concentration and the proportion of hydrofluoric acid and nitric acid in the experiments, and then combined with high pressure microwave heating technology so as to quickly and completely digest the nano-titanium dioxide sample into solution. The composition and ratio and amount of the mixed digestion reagent, and the best microwave heating control program are all optimized in this paper, which not only solved the problem of the digestion of titanium dioxide and the loss of the analyte arsenic that is likely to be volatile in the high temperature digestion process, but also ensure that high content of titanium matrix in the low acidity solution is still existing in a stable complex ion form to avoid hydrolysis by complexation of the fluoride ion. Therefore, it can greatly reduce the detection affection of acidity and avoid the erosion of GF-AAS graphite tube. In order to eliminate the influence of the thermal stable titanium dioxide matrix on the determination of volatile trace element arsenic, the type of graphite tube, graphite furnace atomization procedures and atomic absorption spectrometer detection parameters all have been optimized through the matrix effect testing. The detection limit is 0.000 001% and the recovery rate is in the range of 93.0% to 106.0%. Otherwise, RSD is less than 9.36%, which is consistent with ICP-MS detection method.