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A New Liquid Phase Microextraction and Its Application in Determining Residues of Aromatic Amines、Carbaryl and Triazophos Pesticides

Author: FuLingYan
Tutor: WangXueDong
School: Central China Normal University
Course: Analytical Chemistry
Keywords: Aniline Carbamate Organophosphorus pesticides Dispersive liquid-liquid microextraction Environmental water samples Juice Soil High performance liquid chromatography - variable UV detector High performance liquid chromatography - fluorescence detector
CLC: X839.2
Type: Master's thesis
Year: 2009
Downloads: 204
Quote: 0
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Abstract

Aniline compounds are widely used antioxidants intermediates dyes, cosmetics, pharmaceutical and pesticide industry and polymer industry. Them as the emission of the factory or as a phenyl carbamate, aniline herbicides as well as degradation products of azo dyes, direct or indirect release into the environment. Aniline with high water-soluble, they can easily penetrate the soil pollution of groundwater. Aniline is suspected of having carcinogenic and high toxicity to aquatic organisms, since the 1970s, the United States Environmental Protection Agency part of the aniline has been blacklisted as a matter of priority control. Organophosphate and carbamate as two important types of pesticides, has gradually replaced the organochlorine pesticides should not be decomposed and bioaccumulation. Due to their spectrum of activity, has been widely used in the types of agricultural crops. However, since they are inhibitors of acetylcholinesterase, many substances such compounds is not only highly toxic and suspected to be capable of inducing mutations carcinogenic hazards and endocrine disrupting. These organic pollutants and pesticides pose a serious threat to the environment and human health, there is an urgent need to establish a simple, rapid, economic, sensitive method to detect these trace compounds in environmental media. The liquid-phase microextraction (LPME) based on a sample separation and enrichment of target compounds in the the extraction distribution between the organic solvent and aqueous solution droplets based pre-treatment technology. It overcomes the traditional liquid-liquid extraction technology of the disadvantages of using only microliter or even nanoliter organic solvent extraction, to adapt to the requirements of the development of modern analytical science, is a set of extraction and enrichment in one environment-friendly sample pre-treatment technology. After nearly 10 years of development, the liquid-phase microextraction development of extraction methods have been static, dynamic, cyclic, headspace, hollow fiber membrane and a new micro-extraction dispersive liquid-liquid microextraction. Compared with the traditional liquid-phase microextraction, dispersive liquid-liquid microextraction of the biggest advantages is the extraction time is short, simple operation, a simple and economical instrument. Since the advent of the technology so far, this method has been successfully applied to the analysis and detection of organic pollutants and metal ions in the environment. The papers from the evaluation of dispersion liquid microextraction different types of organic matter in the environment and the applicability of the different substrates, select the aniline (p-toluidine, m-chloroaniline-chloroaniline and Bromoaniline) carbamate and organophosphate pesticides (carbaryl and triazophos) on behalf of two different types of substances in water samples, juices and soil as three different types of substrates, by DLLME pretreatment method, the aniline and carbaryl and triazophos pesticides in various environmental media such as water, fruit juice and soil residue analysis method. The main content of the paper is as follows: First, DLLME and high performance liquid chromatography - UV detection (HPLC-VWD) associated with the Wuhan East Lake and the Yangtze River water four aniline (p-toluidine, chloroaniline, p-chloroaniline and Bromoaniline) were analyzed. The results showed that four aniline compound has good linearity in the 5.0-5000 ng mL ^{-1 , the correlation coefficient between 0.9990-0.9998; enrichment factor between 41-95; detection limit of 0.8-1.8 ng mL ^{-1 ; method recoveries were 85.4-111.7%; reproducible the RSDS to 4.1-5.3%. Secondly, DLLME associated with high performance liquid chromatography - fluorescence detection (HPLC-FLD) the Wenzhou aojiang, East China Sea, water and fruit juice (apple juice, grape juice, peach juice) carbaryl and triazophos The residual amount detection. This method, carbaryl and triazophos 0.1-1000 ng mL ^{-1 has a good linear correlation coefficient between 0.9991-0.9999; enrichment factors were 87.3 and 275.6 ; detection limits were 12.3 and 16.0 pg mL ^{The -1 . Water samples and juice spiked recoveries ranged between 80.4-114.2% and 86.3-117.8%, respectively: the method has good reproducibility, RSDs in the range of 1.38-2.74%. The results show that the kind of juice in water samples and water diluted 1:1 matrix almost no effect on the extraction efficiency of DLLME. Finally, DLLME with HPLC-FLD associated with carbaryl and triazophos in right Wenzhou Aojiang near soil were analyzed. First methanol extract soil pesticide, after methanol extraction liquid dispersant as DLLME. This method, carbaryl 0.1-1000 ng g ^{-1 , with good linearity between triazophos 1-5000 ng g ^{-1 , its associated coefficient between 0.9997-0.9999; detection limit were 14.0 and 110.0 pg g ^{-1 ; recovery of soil between 80.8-111.1%; RSDs in the range of 1.96-4.24%, indicating that the The method has good reproducibility. The results show that the experiment Middle-earth kind of matrix almost no effect on the extraction efficiency of DLLME.}}}}}}}

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