采用固相萃取分离-离子色谱法测定化肥中三聚氰胺的含量。化肥样品经10 g·L-1三氯乙酸溶液振荡超声提取,离心后,萃取液经阳离子交换固相萃取柱净化。经净化的溶液经IonPac NG1保护柱及Dionex IonPac AS18分离柱分离,以含3 mmol·L-1甲基磺酸的乙腈-水(15+85)混合液为淋洗液进行淋洗,所得提取液采用抑制电导检测器进行离子色谱分析。三聚氰胺的质量浓度在5.00~2 000 mg·L-1范围内与其峰面积呈线性关系,检出限(3S/N)为0.3 mg·kg-1。加标回收率在89.7%~97.8%之间,测定值的相对标准偏差(n=6)在1.9%~4.5%之间。

IC was applied to the determination of melamine in fertilizer with separation by SPE. The fertilizer sample was extracted ultrasonically by oscillation with 10 g·L-1 trichloroacetic acid solution. After centrifuging, the extract was purified by passing through cationic exchange solid phase extraction column. IonPac NG1 protective column and Dionex IonPac AS18 separation column were used for IC-separation and a mixture of acetonitrile-water (15+85) (containing 3 mmol·L-1 methyl sulfonic acid) was used as eluant. The eluate was used for IC-analysis using inhibitorty conductivity detection. Linear relationship between values of peak area and mass concentration of melamine was kept in the range of 5.00-2 000 mg·L-1, with detection limit (3S/N) of 0.3 mg·kg-1. Values of recovery found by standard addition method were in the range of 89.7%-97.8%, and values of RSD′s (n=6) in the range of 1.9%-4.5%.