Nafion修饰钨丝圆盘预富集-石墨炉原子吸收法测定煤飞灰中Cr^(3+)

Determination of Cr^(3+) in Coal Fly Ash With Graphite Furnance Atomic Absorption Spectrometry After Preconcentration on Nafion-modified Tungsten Filament Coil

建立一种测定煤飞灰中 Cr3+的方法。样品用氢氟酸消化 ,经 Nafion修饰钨丝圆盘预富集后 ,用石墨炉原子吸收法测定 Cr3+。富集底液选用 0 .0 1mol/ L Na Ac- HAc缓冲溶液 (p H=4.0 ) ,测定线性范围为 10～ 10 0 ng/ ml,检测限为2 .5 ng/ ml,对含 Cr3+量为 5 0 ng/ ml的溶液平行测定 10次 ,相对标准偏差为 5 .9% 。

A method for determination of Cr 3+ in coal fly ash was established in this assay The contents of Cr 3+ in samples,digested by hydrofluoric acid and then preconcentrated by Nafion modified tungsten filament coil,were determined by graphite furnance atomic absorption spectrometry 0 01 mol/L NaAc HAc buffer solution (pH=4 0) was selected as base solution for concentrating samples The linear range and detection limit was 10~100 ng/ml and 2 5 ng/ml respectively in this assay.The parallel determination of a same solution containing 50 ng/ml Cr 3+ was done 10 times with a relative standard deviation of 5 9% In this method any interference was not observed during the determination of samples containing more than 10 kinds of coexisting ions