微波等离子体原子发射光谱法测定森林土壤中的铝

采用微波等离子体原子发射光谱法测定水溶液中金属元素铝,方法的线性范围为0.01~70μg/L,线性相关系数(R)为0.999 8,检出限为0.335μg/L,检测上限为70 mg/L,[H+]浓度低于2 mol/L时,酸度和酸介质对发射强度无显著影响,P酸度=0.188,P酸介质=0.139,均大于α(0.05),且具有较高的精密度和准确度。采用所建立的微波等离子体原子发射光谱法(MP-AES法)测定森林土壤中浸提性铝和全铝的质量分数,分别与LY/T 1257—1999和LY/T 1253—1999中氟化钾取代EDTA容量法相比较,测定结果无显著性差异,P=0.879和P=0.911,均大于α(0.05);同时对测定的土壤中全铝质量分数进行加标回收检验,回收率在99%~104%。MP-AES法可直接使用空气作为工作气体,其安全性高,成本低,条件容易满足。因此,所建立的方法能够满足森林土壤中铝的测定。

Determin ing Al in Forest Soil Using Microwva e Plasma Atomic Emission Spce trometry

We measured the Al content in aqueous solution using microwave plasma atomic emission spectrometry ( MP-AES) , which was with the linearity range of 0.01-70μg/L, good precision and accuracy, the linear correlation coefficients for MP-AES established in aqueous solution of 0.999 8, a detection limit of 0.335μg/L and the detection limits of 70 mg/L. The acidity and acid medium had no significant effect on the emission intensity when [ H+] concentration was lower than 2 mol/L.The content of leaching of Al and full Al were determined by MP-AES established in aqueous solution.Based on the results obtained by method of KF-EDTA in LY/T 1257-1999 and LY/T 1253-1999, MP-AES had no significant differ-ence with the standard method ( KF-EDTA) , and the spiked recoveries in determination of full Al content were in 99%-104%.MP-AES directly using air as the working gas, not only improves the safety, but also saves the operating costs, therefore, it is a feasible method for determining Al in forest soil.