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留学生环境工程化学测定论文-Rapid determination of amide herbicides in environmental

论文作者:留学生论文网论文属性:硕士毕业论文 thesis登出时间:2012-03-07编辑:anterran点击率:5738

论文字数:3522论文编号:org201203071337251526语种:英语 English地区:英国价格:$ 66

关键词:Dispersiveliquid-liquid microextractionGas chromatographymass spectrometry

摘要:提供留学生环境工程化学测定论文-Rapid determination of amide herbicides in environmental-通过环境化学实验研究对环境做出检测评定

ORIGINAL PAPER
Rapid determination of amide herbicides in environmental
water samples with dispersive liquid–liquid microextraction
prior to gas chromatography–mass spectrometry

Abstract This paper describes a novel, simple and environmentallyfriendly method for rapid determination of the
amide herbicides metoalchlor, acetochlor, and butachlor. Itis based on dispersive liquid-liquid microextraction and gaschromatography–mass spectrometry. Factors that may
influence the enrichment efficiency, such as type and volumeof extraction solvent, type and volume of dispersive solvent,extraction time, and content of NaCl, were investigated and
optimized in detail. Under the optimum conditions, the limitsof detection of metoalchlor, acetochlor, and butachlor were
1, respectively. The experimental
results indicated that there was linearity over the range 0.1–
50 μg L−1 and good reproducibility with relative standard
deviations over the range 1.6–3.0% (n=5). The proposedmethod has been applied for the analysis of real-worldwater samples, and satisfactory results were achieved.
Average recoveries of spiked herbicides were in the range80.3–108.8%. All of these indicated that the developed
method would be an efficient method for simultaneousdetermination of the three herbicides in environmental
water samples.
Keywords Dispersive liquid-liquid microextraction .Gas chromatography-mass spectrometry . Metoalchlor .
Acetochlor . Butachlor
Introduction
The wide use of amide herbicides provides the great benefitof increasing agricultural production, however, their residues
are of great concern in environmental contamination.
They are present in surface water and ground waters, andconsidered to be a potential risk or threat for water qualitydue to their heavy use and toxicity. The United StatesEnvironmental Protection Agency (USEPA) has establisheda maximum residue level of acetochlor in groundwater at
0.1 μg L−1 [1]. Hence, rapid, simple and environmentallyfriendly methods are necessary for monitoring the widespread
distribution of these compounds. However, their direct
determination is often difficult because of the complexity of
the environmental matrix and the low concentration of target
pollutants. Fortunately, a number of sample-pretreatment
methods have been developed for the separation and
enrichment of these pollutants, such as liquid-liquid extraction
(LLE) [1], solid-phase extraction (SPE) [2], solid-phase
microextraction (SPME) [3], liquid-phase microextraction
(LPME) [4] and so on.
As is well known, conventional pretreatment methods,
such as LLE and SPE, are time-consuming, tedious, and
often require large amounts of organic solvent. SPME is a
novel and solvent-free sample pretreatment technique [5]. It
reduces sample intake, avoids the use of toxic organic
solvent, and minimizes the number of steps involved in
sample preparation. However, this technique also has some
limitations, for example, its fibers are fragile and have
limited lifetimes; sample carry-over is also a problem [6].
Liquid-phase microextraction was developed as a solventminimized
pretreatment technique, which is fast, simple,
and inexpensive. LPME combines extraction, concentration,
and sample introduction in one step [7]. It is based on
the distribution of the analytes between a few microliters of
Anal Bioanal Chem (2008) 391:291论文英语论文网提供整理,提供论文代写英语论文代写代写论文代写英语论文代写留学生论文代写英文论文留学生论文代写相关核心关键词搜索。

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