微波消解-石墨炉原子吸收光谱法测定钛白粉中钒

以3 mL硫酸-2 mL氢氟酸-2 mL过氧化氢为溶剂,采用4步升温微波消解技术对样品进行消解,设定灰化温度为1 500 ℃,原子化温度为2 700 ℃,建立了石墨炉原子吸收光谱法测定钛白粉中钒的分析方法。实验表明:试液中加入10 mL 0.5 g/L硝酸镁溶液作为基体改进剂可有效增强待测液的吸光度;方法线性范围为0～50 μg/L,方法检出限为0.01 μg/g。采用方法对钛白粉样品中的钒进行测定,结果与常规湿法消解电感耦合等离子体质谱法一致,相对标准偏差(RSD,n=11)为1.9%～3.2%,回收率为98%～100%。

Determination of vanadium in titanium dioxide by graphite furnace atomic absorption spectrometry with microwave digestion

The sample was digested with 3 mL of sulfuric acid, 2 mL of hydrofluoric acid and 2 mL of hydrogen peroxide as solvent by 4-step temperature rising microwave digestion technique. A determination method of vanadium in titanium dioxide was established by graphite furnace atomic absorption spectrometry with ashing temperature of 1 500 °C and atomization temperature of 2 700 °C, respectively. The results showed that the absorbance of test solution could be effectively strengthened by adding 10 mL of 0.5 g/L magnesium nitrate solution as matrix modifier. The linear range of method was 0-50 μg/L, and the detection limit was 0.01 μg/g. This proposed method was applied to determine vanadium in titanium dioxide samples. The results were consistent with those obtained by inductively coupled plasma mass spectrometry after conventional wet digestion. The relative standard deviation (RSD, n=11) of determination results was 1.9%-3.2%, and the recoveries were between 98% and 100%.