| On the analysis of the practice, separation and detection of the trace or ultra trace organic pollutants existing in the complex matrix become a prominent problem. In recent years, although many instrument analysis methods possessing higher sensitivity and selectivity have been developed, high performance liquid chromatographic technique is still one of the wildly application in analytical method. In general, extraction, separation and enrichment of trace organic compound is necessary before the determination by analytical instruments. It is obvious that the pre-treatment procedures of trace compound depend on appropriate separation methods and different functional adsorption materials with larger adsorption capacity and higher selectivity. Therefore, this article established a new method for the determination of trace organic pollutants using the nano carbon material as soild phase extractant and ionic liquid enrichment technology coupled with HPLC in the environment, food and biological samples.Simultaneous separation and enrichment of four endocrine disrupting compounds (bisphenol A, bisphenol F, bisphenol AF and bisphenol AP), based on solid-phase extraction using multi-wall carbon nanotubes as adsorbents. Compared with traditional extraction materials, multi-wall carbon nanotubes show higher extraction efficiency larger absorption capacity and better stability, and it can rapidly complete extraction separation within 10 min and can be reused at least eight times without obvious decrease in the extraction efficiency. The enrichment factors of 500 were obtained. Various experimental parameters including the amount of adsorbents, the pH and ionic strength of sample solution, extraction time, elution conditions co-existing ions and humic acid that could influence the extraction efficiencies had been investigated. A new method for the solid-phase extraction of trace endocrine disrupting compounds in environment water coupled with high performance liquid chromatography was developed. The detection limits of method were in the range of 0.10-0.30 ng mL-1. The extraction recoveries in real samples in the range of 85.3-101.7%(RSD<3.74%).The proposed method is rapid, sensitive and efficient, and offers references to detection of other similar types of compound.Magnetic multiwalled carbon nanotubes (Ni/MWCNTs) were prepared. The morphology, size, structure, specific surface area and particle size distribution, magnetic performance of the Ni/MWCNTs was analyzed by TEM, XRD, BET, VSM. Various experimental parameters that could affect the adsorption and desorption efficiency of lamivudine were investigated. The optimum extraction conditions and quantitative elution conditions were determined. The extracted lamivudine was eluted using ionic liquid (IL) "Green solvents" as substitutes of volatile organic solvents. The elution method have advantages of the high elution efficient, less solvent consumption and high erichment. Adsorption behaviour of Ni/MWCNTs for the extraction separation was investigated, and adsorption mechanism was revealed. Ni/MWCNTs can be separated by the magnet and can be reused for several times. Finally, the method for detection of lamivudine based on a magnetic solid phase extraction using magnetic carbon nanotubes as adsorbents coupled with HPLC was established. Under optimized conditions, a limit of detection of 0.14 ng mL-1 and enrichment factor of 292 were obtained. The recoveries of analytes obtained were in the range of 97.6-103.0% and 93.4-102.2% in river water and human urine samples, respectively. The present method successfully applicated in determination of trace lamivudine from biological fluid and environmental water samples.Microcolumn solid phase extraction preconcentration device using as stationary phase was first developed for the simultaneous determination of carbendazim and thiabendazole residues in in fruits, vegetables, and fruit juice by high performance liquid chromatography. In the process of extraction, sample and elution solution run through U-shaped glass microcolumn (Φ 6 mm×H 19.5mm) packed with carbon nanofibers by peristaltic pump and the process of extraction, enrichment and separation were auto-completed, easy to implement on-line detection. Important influence factors were investigated in detail, including amounts of packing material, sample solution acidity, sample solution and eluent flow rate and volume, and the optimum extraction conditions were determined. Carbon nanofibers exhibited good affinity and excellent stability to target analytes. Solid phase extraction microcolumn can be reused at least five times without obvious decrease in the extraction efficiency. The loading capacities of the carbon nanofibers for carbendazim and thiabendazole were evaluated as 9.1 and 10.6 mg g-1, respectively. Under the optimal conditions, excellent linearity was obtained in a range of 2.0-500.0 ng mL·-1(r2>0.9964). The limits of detection were in the range of 0.45-0.54 ng mL-1 and the recoveries of analytes were in the range of 96.1-103.5%. The results showed that the present method was a simply, convenient and feasible method for the determination of carbendazim and thiabendazole in real samples.A magnetic nanoporous three dimensional graphene (3DG)/ZnFe2O4 composite was successfully achieved by ZnFe2O4 magnetic particles loading on the nanoporous 3D. The morphology, size, structure, specific surface area and particle size distribution and magnetic behavior of the as-prepared 3DG/ZnFe2O4 were characterized by using the techniques of SEM, XRD, BET, FTIR, TGA and VSM, and use it for enrichment and separation of BPS, BPF, TDP, BPA, BPAF, BPAP, BPC, TCBPA and TBBPA. The 3DG/ZnFe2O4 has a high specific surface area and good stability, the enrichment factor of 700 for nine bisphenol analogs (BPs) were obtained, and can be reused at least ten times. In the process of extraction and recycle,3DG/ZnFe2O4 can be separated by the magnet avoiding the complex procedures for the centrifuge and filter, Simplify the extraction process and improving the extraction efficiency. Its performance was evaluated by the magnetic solid-phase extraction of nine BPs from water samples followed by HPLC analysis. Under optimized condition, the lower the limits of detection (0.01-0.11 ng mL-1), good linearity range (0.5-250 ng mL-1 and 1.0-500.0 ng mL-1) and satisfactory recoveries (96.6-103.2%) were achieved. The results indicated that the developed method has the advantages of high efficiency and sensitiveness, and can be successfully applied to detect the nine BPs in large volume of water samples.The elastic cylindrical three-dimensional porous graphene rod was fabricated by a facile one-step hydrothermal method. Draw-inject solid-phase microextraction in a syringe system (MEPS) packed with as-prepare three-dimensional graphene rod (3DGr) coupling with HPLC was developed for the determination of trace BPs in environmental samples. The process of extraction was performed in syringe. Sample solution or elution solution were draw-injected by syringe piston and completed adsorption and desorption process, and then elution solution was injected in HPLC. Through the static adsorption experiment, saturated adsorption capacity of BPS, BPF, TDP, BPA, BPAF, BPAP, BPC, TCBPA and TBBPA were 65.76,60.82,70.34,58.16,96.49,123.51,78.53,89.92 and 91.87 mg g-1, respectively. The extraction conditions that could affect the extraction efficiencies was optimized. The methodology was investigated, and can be successfully applied to the analysis of nine bisphenol analogs in the river water and soil samples. The limits of detection were in the range of 0.39-3.97 ng mL-1 and the recoveries of nine analytes were in the range of 96.5-102.6% in river water and soil, and got the satisfactory resulte. The method based on using high absoption performance and novel nanoporous carbon materials as MEPS absorbents, and has opened up a new approach to the application of traditional solid phase extraction.Ionic liquid (IL) dispersive liquid-liquid microextraction (DLLME) method combined with HPLC was successfully developed for determination of endocrine disrupting compounds (bisphenol A, bisphenol AF and bisphenol AP) from the food packaging. 1-Octyl-3 methylimidazolium hexafluoro-phosphate ([C8MIM][PF6]) was selected as extraction solution. Three target compounds extraction kinetics were found to be very fast and the equilibrium was attained within 3.0 min following the pseudo-first-order model. The extraction procedure did not require a dispersive solvent and extraction efficiencies of target compounds can reach more than 95%, using 200 μL IL as extraction solution. Extraction mechanism may be hydrophobic effect and hydrogen bonding interaction between the IL and target compounds. Target compounds from ionic liquids can be back-extracted by NaOH solution and the recovered IL could be reused for three times without significant loss of extraction efficiencies. The spiked recoveries of three targets in food packaging were in the range of 97.8-103.1%. The limits of detection ranged from 0.50 to 1.50 ng mL-1. The method realizes one step of he extraction, separation and enrichment, shortens the time of sample preparation, and has the advantages of rapid, safe and environment friendly. |
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