荧光衍生化-磁分散固相萃取/高效液相色谱检测池塘水与蔬菜中3种挥发性异味物质

以6-碳酰氯左氧氟沙星(LFC-Cl)为衍生试剂,磁性氧化石墨烯(MGO)为吸附剂,建立了2-甲基异莰醇(2-MIB)、土臭素(GSM)和3-甲基-1-丁醇(3-MB)的高效液相色谱荧光检测(HPLC-FLD)分析方法。在浓度为0.05 mol/L的4-二甲氨基吡啶(DMAP)乙腈溶液中,衍生温度60℃,反应时间90 min,超声波辅助条件下,可完成上述3种醇类挥发性异味物质(VOCs)的衍生化。在吸附剂用量20 mg、萃取时间20 min、解吸剂为乙腈(含1%甲酸)、解吸时间3 min条件下,能实现3种异味物质衍生物的富集和净化。在优化的HPLC条件下,15 min内可实现3种衍生物的基线分离和高灵敏检测。方法检出限(LOD)为0.020~0.95 ng/L,定量下限(LOQ)为0.10~3.3 ng/L,线性、精密度和回收率良好。与已报道的方法相比,该方法具有灵敏度高、样品前处理简单、仪器普适性好等优势,可用于池塘水、蔬菜中VOCs的快速、定量测定,为食品和环境水样监测提供了一种新方法。

Determination of Three Volatile Organic Compounds in Pond Water and Vegetables by High Performance Liquid Chromatography with Fluorescence Derivatization and Magnetic Dispersive Solid Phase Extraction

A new method of high performance liquid chromatography-fluorescence detection(HPLC-FLD) was developed for the detection of 2-methylisoborneol(2-MIB),geosmin(GSM) and 3-methyl-1-butanol(3-MB),with 6-carbonyl chloride levofloxacin(LFC-Cl) as derivatization reagent and magnetic graphene oxide(MGO) as magnetic dispersive solid phase extraction(MDSPE) adsorbent.Through optimizing derivatization conditions,three kinds of volatile organic compounds(VOCs) could be completely derivatized in 0.05 mol/L 4-dimethylaminopyridine(DMAP)acetonitrile solution within 90 min at 60 ℃ under ultrasonic assisted conditions.Through optimizing MDSPE conditions,three VOCs derivatives could be enriched and purified by a 20 min extraction of 20 mg adsorbent followed by a 3 min desorption of acetonitrile containing 1% formic acid.Under the optimized chromatographic conditions,the baseline separation and high-sensitive detection of three VOCs derivatives were realized within 15 min.The limits of detection(LOD) and limits of quantitation(LOQ) of this method were in the ranges of 0.020-0.95 ng/L and 0.10-3.3 ng/L,respectively.The linearity,precision and recoveries were satisfactory.Compared with the reported methods,this method had the advantages of high sensitivity,simple sample pretreatment and universal instruments.It was suitable for the rapid determination of three VOCs in pond water and vegetables,providing a new approach for the monitoring of food and environmental water samples.