An Jiwoo, Rahn Kira L, Anderson Jared L
Department of Chemistry, Iowa State University, Ames, IA 50011, USA.
Department of Chemistry, Iowa State University, Ames, IA 50011, USA.
Talanta. 2017 May 15;167:268-278. doi: 10.1016/j.talanta.2017.01.079. Epub 2017 Jan 30.
A headspace single drop microextraction (HS-SDME) method and a dispersive liquid-liquid microextraction (DLLME) method were developed using two tetrachloromanganate ([MnCl])-based magnetic ionic liquids (MIL) as extraction solvents for the determination of twelve aromatic compounds, including four polyaromatic hydrocarbons, by reversed phase high-performance liquid chromatography (HPLC). The analytical performance of the developed HS-SDME method was compared to the DLLME approach employing the same MILs. In the HS-SDME approach, the magnetic field generated by the magnet was exploited to suspend the MIL solvent from the tip of a rod magnet. The utilization of MILs in HS-SDME resulted in a highly stable microdroplet under elevated temperatures and long extraction times, overcoming a common challenge encountered in traditional SDME approaches of droplet instability. The low UV absorbance of the [MnCl]-based MILs permitted direct analysis of the analyte enriched extraction solvent by HPLC. In HS-SDME, the effects of ionic strength of the sample solution, temperature of the extraction system, extraction time, stir rate, and headspace volume on extraction efficiencies were examined. Coefficients of determination (R) ranged from 0.994 to 0.999 and limits of detection (LODs) varied from 0.04 to 1.0μgL with relative recoveries from lake water ranging from 70.2% to 109.6%. For the DLLME method, parameters including disperser solvent type and volume, ionic strength of the sample solution, mass of extraction solvent, and extraction time were studied and optimized. Coefficients of determination for the DLLME method varied from 0.997 to 0.999 with LODs ranging from 0.05 to 1.0μgL. Relative recoveries from lake water samples ranged from 68.7% to 104.5%. Overall, the DLLME approach permitted faster extraction times and higher enrichment factors for analytes with low vapor pressure whereas the HS-SDME approach exhibited better extraction efficiencies for analytes with relatively higher vapor pressure.
开发了一种顶空单滴微萃取（HS-SDME）方法和一种分散液液微萃取（DLLME）方法，使用两种基于四氯锰酸盐（[MnCl]）的磁性离子液体（MIL）作为萃取溶剂，通过反相高效液相色谱（HPLC）测定包括四种多环芳烃在内的十二种芳香族化合物。将所开发的HS-SDME方法的分析性能与采用相同MIL的DLLME方法进行了比较。在HS-SDME方法中，利用磁体产生的磁场将MIL溶剂悬浮在棒状磁体的尖端。在HS-SDME中使用MIL可在高温和长萃取时间下形成高度稳定的微滴，克服了传统SDME方法中常见的液滴不稳定挑战。基于[MnCl]的MIL的低紫外吸光度允许通过HPLC直接分析富集了分析物的萃取溶剂。在HS-SDME中，研究了样品溶液的离子强度、萃取系统温度、萃取时间、搅拌速率和顶空体积对萃取效率的影响。测定系数（R）范围为0.994至0.999，检测限（LOD）在0.04至1.0μg/L之间，湖水的相对回收率在70.2%至109.6%之间。对于DLLME方法，研究并优化了包括分散剂溶剂类型和体积、样品溶液的离子强度、萃取溶剂质量和萃取时间等参数。DLLME方法的测定系数在0.997至0.999之间，LOD在0.05至1.0μg/L之间。湖水样品的相对回收率在68.7%至104.5%之间。总体而言，DLLME方法对于蒸气压低的分析物允许更快的萃取时间和更高的富集因子，而HS-SDME方法对于蒸气压相对较高的分析物表现出更好的萃取效率。
