Applications Of Solid Phase Microextraction Combined With Gas Chromatography Technology For The Determination Of Several Organic Pollutants

Sample preparation is a critical step in the whole analysis process. Traditional samplepreparation methods, such as liquid liquid extraction (LLE) and soxhlet extraction (SE),are organic solvent-consuming, tedious, and difficult for automation to some extent.Therefore, a lot of research efforts have been focused on the development of new samplepreparation techniques, which are simple, effective and rapid. So far, some new samplepreparation methods have been developed, including liquid liquid microextraction (LLME),purge and trap (PT), solid-phase microextraction (SPME) and so on. SPME combines theextraction, preconcentration, and sample introduction into one simple step with theadvantages of simplicity, rapidity, portable, effectiveness and minimum use of solvents.In this work, on the basis of dispersive liquid–liquid microextraction (DLLME)，solid-phase extraction (SPE) and solid phase microextraction (SPME) in combination withgas chromatography (GC), analytical methods were developed for the determination ofseveral organic pollutants in water and drink samples. This thesis is mainly concerned withthe following aspects:1. A novel analytical method was developed for the determination of five acetanilideherbicides (alachlor, acetochlor, metolachlor, butachlor and pretilachlor) in water and greentea samples by graphene-based magnetic solid phase extraction-dispersive liquid liquidmicroextraction method followed by gas chromatography with flame ionization detection(GC-FID). Some important experimental parameters that could influence the extractionefficiencies were investigated. Under the optimum conditions, as high as3399to4002foldenrichment factors were achieved. A good linearity existed in the range of0.1~50.0μg/Lfor all the five herbicides with the correlation coefficients (r) varying from0.9973to0.9993. The limits of detection ranged from0.01to0.03μg/L, and the relative standarddeviations were between3.8%and5.8%. The method was applied to the analysis of theacetanilide herbicides in environmental water and green tea samples with a satisfactoryresult.2. A rapid and solvent-free analytical method for the determination of BTEX (benzene,toluene, ethylbenzene and xylene) in real samples was developed, which was based on theheadspace-solid phase microextraction (HS-SPME) with graphene (G) as the SPME fibercoating material, followed by gas chromatography-flame ionization detection. The desorption temperature and time, sample solution volume, extraction time, ionic strength,and stirring rate were optimized. Under the optimal conditions, the linear response wasobserved over the range of0.02~160μg/L, with the correlation coefficients (r) varyingform0.9957~0.9987. The limits of detection were in the range between0.5to2ng/L(S/N=3). The recoveries ranged from81.4%to111.8%and the relative tandard deviationsfell between3.5%and5.1%. The method was successfully applied for the analysis ofBTEX in carbonated drinks, tap water and mineral water samples.