离子色谱法测定福建南平地区植烟土壤中的全钾和有效钾含量

Determination of total potassium and available potassium in tobacco soil from Nanping by ion chromatography

建立测定植烟土壤中全钾和有效钾含量的离子色谱法。采用Dionex RFIC CS12A阳离子交换色谱柱(4.0mm×250 mm)配Dionex CG12A保护柱(4 mm×50 mm),以20 mmol/L甲基磺酸为流动相,流速1.0 m L/min,检测器为电导检测器,柱温25℃,进样量25μL。结果表明:钾离子在1.5~15 mg/L内与峰面积的线性关系良好,线性方程为:y=5.634x-0.252 8,r=0.999 3;最低检出限为0.31 mg/kg;定量限为1.01 mg/kg。样品中全钾和有效钾在不同浓度水平范围内的平均回收率测定结果为98.31%~101.3%,RSD(n=6)为0.5%~3.9%,表明该方法具有良好的准确性和精密度,操作简便、快速,可以满足实际分析的需要。样品分析的结果表明,邵武地区的砂土含钾量(包括全钾和有效钾)最高,而浦城地区的壤土含钾量最高,为该地区烟草培植施用钾肥提供了参考。

A method for the determination of total and available potassium in tobacco soil was developed by ion chromatogra- phy. Dionex RFIC CS12A separation column and CG12A protective column were used for separation and the mobile phase was 20 mmoL/L methanesulfonic acid solution, the flow rate was 1.0 mL/min with suppressed conductivity detector, and the column temperature was 25℃ and the inject volume was 25μL. The results showed that the calibration curve was linear in the range of 1.5 - 15 mg/L with a correlation coefficient （r） of 0. 999 3, and the linear equation was y =5. 634x -0. 252 8. The detection and quantification limit were 0. 31 mg/kg and 1.01 mg,/kg, respectively. The recovery of standard addition were from 98.31% to 101.3% , and the RSD （n =6） were from 0. 5% to 3.9%. This method was credible, simple, fast, and suitable for the analysis of potassium in soil. The analytical results showed that sandy soil from Shaowu and loam soil from Pucheng had the highest potassium content, including total potassium and available potassium. These conclusions were helpful for potassium fertilizer application in tobacco soil.