重铬酸钾溶液浸取-电感耦合等离子体原子发射光谱法测定稀土镁硅铁合金中氧化镁

Determination of magnesium oxide in rare earth magnesium ferrosilicon alloy by inductively coupled plasma atomic emission spectrometry after leaching with potassium dichromate solution

采用40g/L重铬酸钾溶液作为氧化镁的浸取剂,在室温下震荡样品30min,过滤后选择279.553nm、280.270nm、285.213nm 3条谱线中的任一条谱线作为分析线,在优化仪器参数的条件下用电感耦合等离子体原子发射光谱法(ICP-AES)测定滤液中的氧化镁,从而建立了稀土镁硅铁合金中氧化镁的测定方法。方法的检出限(质量分数)分别为0.003 0%(279.553nm)、0.002 7%(280.270nm)、0.0043%(285.213nm),测定下限(质量分数)分别为0.030%(279.553nm)、0.027%(280.270nm)、0.043%(285.213nm),铁、钾、铬、稀土的允许量(μg/mL)分别为150、2 000、6 000、200,试液中2g/L重铬酸钾产生基体效应对测定的影响可以忽略不计。方法应用于实际样品中氧化镁的测定,测定值与原子吸收光谱法的测定值相符,测定结果的相对标准偏差小于5%。

A method for the determination of magnesium oxide in rare earth magnesium ferrosilicon al- loy was established. 40 g/L potassium dichromate solution was used as the leaching agent for magne- sium oxide. The sample was shaken for 30 rain at room temperature and filtered. One of three spectral lines 279. 553 nm, 280. 270 nm and 285. 213 nm was selected as the analytical line, and under the opti- mized instrument parameters, inductively coupled plasma atomic emission spectrometry （ICP-AES） was employed for the determination of magnesium oxide in the filtrate. The method＇s detection limits （mass fraction） were 0.003 0 for 279. 553 nm, 0.002 7 for 280. 270 nm and 0.004 3 % for 285. 213 nm. The limits of quantitation （mass fraction） were 0. 030 for 279. 553 nm, 0. 027 % forof the determination results were less than 5 .