离子色谱法测定土壤中无机阴阳离子含量

摘要

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%.%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^-、SO4^2-、PO4^3）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^＋、Mg^2＋、Ca^2＋）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^-、SO4^2-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．μg·L^-1，Na^＋、K^＋、Mg^2＋、Ca^2＋等4种阳离子的检出限（38／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。