离子色谱法测定土壤中无机阴阳离子含量

IC Determination of Inorganic Anions and Cations in Soil

提出了离子色谱法快速测定土壤中无机阴、阳离子的方法。IonPac AS11-HC分析柱及淋洗液30mmol.L-1氢氧化钾溶液用于6种阴离子(F-、Cl-、NO2-、NO3-、SO42-、PO43-)的分离;IonPac CS12A分析柱及淋洗液20mmol.L-1甲烷磺酸溶液用于4种阳离子(Na+、K+、Mg2+、Ca2+)的分离。测定中采用抑制电导检测器。10种离子的质量浓度均在一定的范围内呈线性关系,F-、Cl-、NO2-、NO3-、SO42-等6种阴离子的检出限(3S/N)分别为5.0,5.0,6.1,6.8,5.8,10.0μg.L-1,Na+、K+、Mg2+、Ca2+等4种阳离子的检出限(3S/N)分别为6.2,5.1,10.0,10.0μg.L-1。方法用于土壤中无机离子的测定,阴、阳离子的回收率在95.6%～103%之间。

The contents of 6 anions and 4 cations in soil were determined by ion chromatography （IC）. IonPac AS11-HC column with 30 mmol · L^-1 KOH solution as eluant was used for separation of the 6 anions, i. e., F^-, Cl^-, NO2^- , NO3^- , SO4^2- andPO4^3-, andlonPac CS12Acolumnwith20mmol·L^-1 methylsulfonie acid as eluant was used for separation of the 4 cations, i. e. , Na^＋. K^＋, Mg^2＋ and Ca^2＋. Inhibitory conductivity detections were adopted in the determination. Linearity was found in the definite ranges for all the 10 ions, with values of detection limits （3S/N） of 5.0μg ·L^-1 for F , 5.0 μg · L^-1 for Cl^-, 6. 1μg · L^-1 for NO2^-, 6. 8μg· L^-1 for NO3^- , 5.8μg · L^-1 for SO4^2- and 10. 0 μg · L^-1 for PO4^3- , 6. 2 μg· L^-1 for Na^＋ , 5.1μg · L^-1 for K^＋ , 10. 0μg · L^-1 for Mg^2＋ and 10. 0 μg ·L^-1 for Ca^2＋. The proposed method was applied to the determination of 10 inorganic ions in soil, giving values of recovery in ＂the range of 95. 6%-103%.