The Application Of Liquid-Phase Microextraction To The Analysis Of Phenolic Compounds In Water And The Isolation Of The Effective Compounds On Oncomelania Hupensis From Reineckea Carnea

Phenolic compounds, mainly coming from the plastics, dyes, pesticides, paper and petrochemical products, are one of the most important contaminants present in the environment. They are often found in waters, soils and sediments. Because of their toxicity, some of them have been included in the lists of priority pollutants in many countries and required to be determined.Liquid-phase microextraction (LPME) is developed as a solvent-minimized pre-concentration technique. LPME is based on the distribution effect of the analytes between a microdrop of organic solvent and aqueous sample solution. With inexpensive apparatus, LPME virtually eliminates solvent consuming, and combines extraction, preconcentration and sample introduction in one step. LPME is usually applied to the analysis of the analytes in water and biologic samples.In this thesis the author summarizes the development and application of LPME in the field of chromatography and studies the possibility of the joint use of LPME-GC-FID to detect in wastewater of a coking factory six mixed phenolic compounds, namely, phenol, o-cresol, m-cresol, 2,4-dimethylphenol, 2,3- dimethylphenol and 3,4-dimethylphenol. Factors that affect the efficiency of LPME such as the extractive solvents, extractive time, extractive temperatures, stirring speed, solvent volume, water sample volume and ionic strength have been optimized, and good repeatability and sensitivity have been gained. High-sensitivity and fast methods to detect phenolic compounds in wastewater by the pretreatment of two modes of LPME (D-LPME, CFME) have been set up.Firstly, D-LPME followed with GC-FID has been applied to the analysis of phenolic compounds in wastewater, with the influential factors in experiment optimized. The developed protocol was found to yield a linear calibration curve in the concentration ranging from 10 10000 μg L^-1 for the target analytes and the limits of detection were in the low μgL^-1 level, ranging between 0.94 and 1.97 μgL^-1. The recoveries were 92— 102%. Good repeatability of extraction was obtained, with the RSD values between 0.96%and 9.37%. The method analyses the analytes rapidly and has good enrichment of the analytes and sensitivities.Secondly, CFME combined with GC-FID has been applied to the analysis ofphenolic compounds. The developed protocol was found to yield a linear calibration curve in the concentration ranging from 10 to 10000 figh^l and the limits of detection ranged between 1.37 and 2.95 jugLT1. The recoveries were from 96 to 98%, with the RSD values between 1.48 and 6.89%. The method has not only leaded to efficient analysis to the analytes, simple operation, good enrichment, but also has easily realized the automatization of extraction by control of the flow rate and extraction time.Finally, the standard method was applied to the analysis of phenolic compounds. Also the results of the analysis by the standard method have been compared to the results by two different modes of LPME. The results prove that the LPME is rapid, inexpensive and reliable.In addition, the author participated in the research of the activity on Oncomelania hupensis of Reineckea carnea and the isolation effective compounds from the Reineckea carnea.Schistosomiasis is a serious epidemic disease, which is harmful for human health and the development of society economy, and is a common healthful puzzle for every government. The practice of the prevention schistosomiasis work shows that the reason for the unsuccessful prevention of schistosomiasis is that Oncomelania hupensis can't been absolutely killed. Oncomelania hupensis is amphibious animal and is the only middle host. Killing Oncomelania hupensis is an effective measure to prevent schistosomiasis.It is recently discovered that the Reineckea carnea is effective in killing Oncomelania hupensis. The poison of this plant has been tested on the Oncomelania hupensis and fish. The result showed that there are many compounds effective on oncomelania hupensis in the plant. The compounds isolated from the water phase and phase from the Reineckea carnea have been effective in killing Oncomelania hupensis. The hexane-l,2,3,4,5,6-hexaol has been isolated from the water phase. The author hasn't got a pure compound from Reineckea carnea which is effective in oncomelania hupensis but has low poison in fish because of the diffculty, time, experience etc.