离子色谱法测定农田灌溉水中亚硝酸盐

Determination of Nitrite in Irrigation Water by Ion Chromatography

本文建立了离子色谱法结合电导检测农田灌溉水中NO2-离子的新方法。分析柱采用容量高、亲水性强的Dionex IonPac AS 19阴离子交换柱,EG40在线产生KOH淋洗液,等浓度泵作梯度淋洗。该方法对亚硝酸盐的检出限为0.028μg·L-1,在0～5.0μg·L-1范围内具有良好的线性关系(r=0.999 9)。将该方法用于农田灌溉水中亚硝酸盐的检测,实际样品的加标回收率在96.7%～105.6%之间,农田灌溉水连续进样6次,相对标准偏差(RSD)为2.70%。

A new method was developed for determination of tracing NO2^- in irrigation water by ion chromatography with conductivity detection in this paper. The separation of the nitrite was achieved on IonPac AS19 column with KOH as gradient eluent and the detection was performed by conductivity detection. The detection limit of nitrite was 0.028μg·L^-1. The tinear range was well in 0-5.0μg·L^-1. The method was applied to the detection of nitrite in irrigation water. The recoveries of spiked standard were 96.7%-105.6%. The RSD of the peak area for the six successive injections of irrigation water was 2.70%.