电喷雾-离子迁移谱快速筛查淀粉中的顺丁烯二酸

Rapid screening of maleic acid in starch matrix by ion mobility spectrometry

目的建立电喷雾-离子迁移谱（ESI-IMS）快速筛查淀粉中顺丁烯二酸的检测方法。方法样品经80%甲醇水溶液超声提取,稀释定容后经0.22μm微孔滤膜过滤,在大气压条件下,以ESI作为电离源,空气作为迁移气体,在负离子模式进行检测,基质外标法定量。结果顺丁烯二酸在5-50μg/ml范围内呈现良好的线性关系,相关系数（r）为0.998 3,检出限为2μg/ml,定量限为5μg/ml。在5.0、10.0、50.0 mg/L 3个浓度加标水平下,顺丁烯二酸的平均回收率为87.5%-96.0%,相对标准偏差（RSD）为3.58%-7.07%。结论本文建立的方法样品前处理方法简单、操作快速简便、结果稳定可靠,适用于淀粉样品中顺丁烯二酸的快速筛查。

Objective A method was developed for the rapid screening of maleic acid in starch matrix by electrospray ionization-ion mobility spectrometry（ ESI-IMS）. Methods The samples were extracted by ultrasound with 80% methanol and diluted with methanol,then the supernatant was filtered with 0. 22 μm microporous membranes. The IMS was operated in the negative mode at ambient pressure using ESI as the ionization source and dry,clean air as drift gas and the analytes were quantified by the matrix-matched external method. Results The calibration curves showed good linearity within the range of 5-50 μg / ml with the correlation coefficients（ r） of 0. 998 3. The limits of detection（ LODs） of maleic acid in starch matrix was 2 μg / ml,and the limit of quantification（ LOQs） was 5 μg / ml. The average recoveries of maleic acid in starch matrix at three spiked levels（ 5. 0,10. 0,50. 0 mg / L） were 87. 5%-96. 0% with the relative standard deviations（ RSD） of 3. 58%-7. 07%. Conclusion The method is simple,rapid and feasible,and could be applied as a screening method for the analysis of maleic acid in starch sample.