离子色谱法同时测定植物生长调节剂中氯化胆碱、甲哌鎓及N-甲基哌啶

Ion chromatographic method for simultaneous measurement of choline chloride, mepiquat chloride and Nmethylpiperidine in plant growth regulators

建立了一种离子色谱-抑制电导同时测定植物生长调节剂中主要活性成分氯化胆碱、甲哌鎓以及杂质N-甲基哌啶的快速检测方法。样品经稀释过膜后直接进样分析,采用阳离子交换色谱柱thermo scientific ionpac CG17 (50 mm×4 mm)+CS17 (250 mm×4 mm),以10 mmol·L^(-1)甲烷磺酸溶液等度淋洗,可在10 min内完成以上目标分析物的检测,且常规阳离子(Li^+、 Na^+、 NH_4^+、 K^+、 Mg^(2+)和Ca^(2+))不会干扰对3种化合物的测定。在优化后的最佳色谱条件下,氯化胆碱的线性范围为0.1～500 mg·L^(-1),甲哌鎓的线性范围为0.5～500mg·L-1,N-甲基哌啶的线性范围为0.4～200 mg·L^(-1),3种化合物线性相关系数(r)均大于0.999 4,线性关系良好。3种目标分析物的检出限(信噪比S/N=3)为28.0～112.5μg·L^(-1),定量限(信噪比S/N=10)为93.5～375.0μg·L^(-1),峰面积的相对标准偏差(RSD, n=6)均小于0.47%,表明方法具有较好的重现性。该检测方法简单方便,已成功应用于商品化植物生长调节剂中3种成分质量浓度的测定,实际样品加标回收率为96.0%～103.6%。可应用于相关植物生长调节剂原料及成品的质量控制。

This paper presents a rapid and simple method for simultaneous measure of the main active components choline chloride,mepiquat chloride,and the impurity N-methylpiperidine in plant growth regulators using ion chromatography with suppressed conductivity detection.According to this method,the samples are diluted in deionized water and then undergo a process of membrane filtration.The filtrate is directly injected into an ion chromatograph equipped with a commercially available cation-exchange column Thermo Scientific Ionpac CS17 (250 mm X 4 mm).The determination of target analytes can be finished in less than 10 min with an isocratic eluent consisting of 10 mmol ? L ^-1 methane sulfonic acid (MSA),and no interferences exist between common cations (Li^+,Na^-,NH4^-,K^-,Mg^2+and Ca^2+ and target analytes.Under the optimal conditions,the proposed method shows good linearity in the range from 0.1 to 500 mg ·L^-1 for choline chloride,from 0.5 to 500 mg · L^-1 for mepiquat chloride and from 0.4 to 200 mg·L-1 for N-methylpiperidine,with correlation coefficients (r)≥ 0.999 4.Limits of detection (LODs,S/N = 3) are in the range from 28.0 to 112.5 μg· L^-1 and Limits of quantitation (LOQs,S /N = 10) are in the range from 93.5 to 375.0 μg·L^-1.It also has a good repeatability (RSDs ≤ 0.47%,n = 6).This method has been successfully applied to rapid and simultaneous analysis of the three compounds in commercial plant growth regulators.The overall average recoveries range from 96.0% to 103.6%.The proposed method can be applied to the quality control of raw materials and commercial products of plant growth regulator.