The Application Of Novel Adsorption Materials For Separation And Enrichment Of The Organic Compounds

The dissertation summarizes the common methods of sample pre-treatment usingsolid phase extractants, including solid-phase extraction (SPE), solid-phasemicroextraction (SPME), matrix solid-phase dispersion (MSPD) and so on. In this paper,our study mainly focuses on the adsorption of some organic compounds in environmentby solid phase extractants.1. The silica modified with [BMIM]CF3SO3as selective solid-phase extractant fordetermination of8OCPs in natural sample[BMIM]CF3SO3-modified silica was obtained by a surface modifying technique onsilica for preconcentration of organochlorine pesticides (OCPs) from natural water.Rapid analysis of OCPs in ground water was developed by on-linesolid-phase-extraction coupled with gas chromatography-mass spectrometry. Theseparation conditions of the analyte, which included the effects of the sample pH, thesample flow rate, the elution flow rate, the type of elution, the elution volume, thesample volume on the recovery of the analyte were investigated. The detection limits ofthis method for8OCPs were0.2-1.8μg/L. The proposed method can be applied todetect8OCPs in natural water sample with satisfactory results.2. Flow injection solid-phase extraction for the determination of PAHs in water byGC-MSA method of on-line solid-phase-extraction preconcentration for the determinationof polycyclic aromatic hydrocarbons (PAHs) by gas chromatography-massspectrometry (GC-MS) was developed based on self-made micro-column filled withmultiwalled carbon nanotubes (MWCNTs). The preconcentration of PAHs on theMWCNs was carried out based on the adsorption retention of analyte via on-lineintroducing the sample into the mini-column system. Methanol was introduced to elutethe retained analyte for GC-MS detection using selected ion monitoring (SIM) mode. Important influence factors were studied in detail, such as sample acidity, sample flowrate, eluent tpye, eluent volume. Limits of detection of PAHs for an extraction of50mLwater sample were in the range of0.001-0.15ug/L, and the precisions (RSD) were inthe range of4-14%. The optimized method was successfully applied to thedetermination of PAHs in surfac ewaters, with recoveries in the range of72%-93%forreal spiked sample.3. Determination of6tetracycline antibiotics in milk by MSPD using MWCNTscoupled with HPLCA matrix solid-phase dispersion extraction (MSPDE) method was developed toextract6tetracycline antibiotics (TCs) from milk samples using multiwalled carbonnanotubes (MWCNTs) as adsorbent prior to high performance liquid chromatography(HPLC) determination. TCs spiked milk samples were blended with MWCNTs, oxalicacid and EDTA. This mixture was packed into a glass syringe as dispersion column. Theanalytes were eluted with methanol containing formic acid, and detected by HPLC withvariable wavelength detector at365nm. The limits of detection (LODs) of6TCs rangedfrom0.01to0.03μg/mL. Recoveries of the spiked milk samples were in the range of78.7~105.2%with relative standard deviations of no more than12%. The resultsshowed that the recoveries of6TCs obtained by MSPD using MWCNTs were higherthan those obtained by using C18, suggesting that the developed MSPD procedure canbe applied for the multiresidues analysis of pesticides and veterinary drugs in foods.