离子色谱法同时测定土壤中7种水溶性阴离子

Simultaneous Determination of 7 Kinds of Water-soluble Anions in Soil by Ion Chromatography

利用ECO-IC离子色谱仪,选择A5-250阴离子分离柱及A5保护柱,采用化学抑制器降低背景电导率,电导检测器检测。通过对流动相配比及进样量等色谱条件进行改进优化,采用4.5 mmol/L Na_(2) CO_(3)和1.2 mmol/L NaHCO_(3)混合溶液为流动相,流速为0.7 mL/min,进样量为25μL时,以标准色谱图各组分保留时间定性,色谱峰面积外标法定量,建立了一种快速准确的离子色谱法在13 min内同时测定土壤中F-、Cl-、Br-、NO_(2)-、NO_(3)-、PO 43-和SO_(4)^(2-)7种阴离子含量的方法,方法线性相关性好(r>0.999)、检出限低(0.14~1.84 mg/kg)、精密度高(0.47%~4.6%),有证标准物质测定结果在其标准值范围内,测量结果相对误差为-8.3%~7.9%,加标回收率为89.0%~108%,方法简单、快速、准确,适合批量土壤样品中阴离子的检测,具有重要的应用价值。

The A5-250 anion separation column and A5 protection column were selected,the chemical repressor was used to reduce the background conductivity,and the conductance detector was used to detect by ECO-IC ion chromatograph.By improving the chromatographic conditions such as flow matching ratio and injection volume,4.5 mmol/L Na_(2) CO_(3) and 1.2 mmol/L NaHCO_(3) were mixed as the eluent.The flow rate was 0.7 mL/min,and the injection volume was 25μL.The retention time of each component was qualitatively determined by standard chromatogram and quantified by external standard method of chromatographic peak area.Based on the above,a rapid and accurate ion chromatography method was developed for the simultaneous determination of seven soluble anion content in the soil(F-,Cl-,Br-,NO_(2)-,NO_(3)-,PO 43-and SO_(4)^(2-))within 13 min.It was well relevant(r>0.999),low limit(0.14—1.84 mg/kg),and high precision(0.47%—4.6%).The results of the certified standard substances were within confidence interval.The relative error range were-8.3%-7.9%,and the recoveries were 89.0%~108%.This method is simple,rapid and accurate,and is suitable for the detection of anions in soil samples.