离子色谱法(IC)分析小麦中的矮壮素和缩结胺

建立了离子交换色谱-直接电导法同时测定小麦中矮壮素和缩结胺残留的分析方法。样品磨碎超声提取后,过固相萃取(SPE)柱去除蛋白质,用0.22μm膜过滤,进样检测。考察了不同的阳离子色谱柱SH-CC-1、SH-CC-2、SH-CC-3,不同的淋洗液对矮壮素、缩结胺的保留时间和分离度的影响。确定了最佳色谱条件为SH-CC-3阳离子色谱柱,直接电导检测,淋洗液选用甲烷磺酸(3.0mmol/L)分离;流速1.0mL/min;柱温40℃;进样量100μL。在此条件下,矮壮素及缩结胺在0.20～20.0mg/L范围内,线性相关系数r均大于0.999,矮壮素和缩结胺的检出限分别为0.070和0.073mg/L,矮壮素、缩结胺的加标回收率分别为76.0%～93.8%和74.9%～91.2%,相对标准偏差在4.2%以下。方法选择性好,灵敏度高,抗干扰能力强,适用于检测小麦中矮壮素和缩结胺的含量。

Determination of Chlormequat Chlorideand Mepiquat Chloride in Wheat by Ion Chromatography

An analytical method for simultaneous determination of chlormequat chloride (CQ) and mepiquat chloride(MQ) residues in wheat was developed by ion exchange chromatography (IC)with direct conductivity detection.After being ground and extracted by ultrasonic treatment, the sample passed through SPE column to remove proteins and then was filtered by 0.22 μm filtering membrane.The chromatographic separation was performed on SH-CC-1, SH-CC-2 and SH-CC-3 cation exchange columns with corresponding eluents.The effects of chromatographic column and types of eluents on the separation and retention factors for the CQ and MQ were investigated.The optimized chromatographic conditions for the determination of the MQ and CQ were as following: 3.0 mmol/L MSA as eluent, a column temperatures of 40 ℃ and a flow rate of 1.0 mL/min, SH-CC-3 cation exchange column, sample loop: 100 uL.Under the optimal conditions, the calibration curves for MQ and CQ were linear in the range of 0.20 to 20.0 mg/L(r≥0.999).The limits of detections for CQ and MQ were 0.070 and 0.073 mg/L, respectively.The standard addition recoveries for the CQ and MQ were about 76.0%~93.8% and 74.9%~91.2%, respectively.The RSD of the MSA peak area was below 4.2%.This method was simple, rapid, accurate and sensitive with a small matrix interference, thus suitable for determination of MQ and CQ in wheat.