Selective Trace Analysis of Sulfonylurea Herbicides in Water and Soil Samples Based on Solid-Phase Extraction Using a Molecularly Imprinted Polymer

Abstract

A molecularly imprinted polymer (MIP) was synthesized using the herbicide metsulfuron-methyl (MSM) as a template, 2-(trifluoromethyl)acrylic acid as a functional monomer, divinylbenzene as a cross-linker, and dichloromethane as a porogen. This polymer was used as a solid-phase extraction material for the quantitative enrichment of five sulfonylureas (nicosulfuron, thifensulfuron-methyl, metsulfuron-methyl, sulfometuron-methyl, and chlorsulfuron) in natural water and soil samples and off-line coupled to a reversed-phase HPLC/diode array detection (HPLC/DAD). Washing solvent was optimized in terms of kind and volume for removing the matrix constituents nonspecifically adsorbed on the MIP. It has been shown that the nonspecific binding ability of the sulfonylureas to the polymer largely increased along with increasing the concentration of Ca2+ ions in the water sample, whereas complexation of divalent ions with EDTA eliminated this interference completely. The stability of MIP was tested by consecutive percolation of water sample, and it was shown that the performance of the MIP did not vary even after 200 enrichment and desorption cycles. Recoveries of the five sulfonylureas extracted from 1 L of tap water and surface water samples such as river water and rainwater at a 50 ng/L spike level were not lower than 96%. The recoveries of sulfonylureas extracted from 10-g soil sample at the 50 microg/kg level were in the range of 71-139%. Depending on the particular compound, the limit of detection varied from 2 to 14 ng/L in water and from 5 to 12 microg/kg in soil samples. The MIP was also compared with a commercially available C-18 column and an immunoaffinity support with encapsulated polyclonal anti-MSM antibodies in sol-gel glass.

Comparison of Multiwalled Carbon Nanotubes and a Conventional Absorbent on the Enrichment of Sulfonylurea Herbicides in Water Samples

“…13 The column temperature was 25˚C, the chromatographic data were acquired at a wavelength of 236 nm and the injection volume was 50 μl. Agilent LC-3D ChemStation for LC systems were used to control the chromatographic units, and to acquire and process the chromatographic data.…”

“…For example, molecularly imprinted polymers have been synthesized and used as recognition matrixes in a coupled SPE system in order to enhance the specificity and selectivity for sulfonylurea herbicides. 13 In recent years, a novel carbonaceous material, multiwalled carbon nanotubes (MWCNTs), was successfully observed to absorb increasing attentions. On the basis of their peculiar electronic, metallic and structural characteristics, 14 they have been exploited in analytical and other fields, such as biosensor, 15 modified electrode, 16 and fieldeffect transistors.…”

Rapid and accurate hplc-dad method for the determination of the herbicide bispyribac-sodium in surface water, and its validation

“…7 Recent publications show that there is a tendency to utilize sophisticated techniques such as GC-MS and LC-MS in the determination of pesticide residues in water. [7][8][9] However, methods that utilize HPLC with ultraviolet absorbance or diode array detection are widely used [10][11][12][13][14] and are fitting for the analysis of herbicides in water, without requiring an elevated investment in instrumentation.…”

“…SPE is the most common technique for the determination of pesticide residues by chromatographic methods in aqueous samples. [7][8][9][10][11][12][13][14][15] The objectives of this study were: to develop and validate a simple and quick method, utilizing SPE and HPLC-DAD, to quantify the herbicide bispyribac-sodium in samples from surface water, especially those with high organic content, like river water and irrigated rice water. …”

Selective Solid-Phase Extraction Using Molecularly Imprinted Polymer for Analysis of Methamidophos in Water and Soil Samples

“…The fact that MIP can bind a particular analyte from a mixture of complex matrices makes MISPE a very promising technique for the development of selective extraction and accurate determination for trace analysis. 16,17) y To whom correspondence should be addressed. Zhong-Lan SHEN, Shandong Supervision and Inspection Institute for Product Quality, Jinan, 250100, China; Tel: +86-531-89701895; Fax: +86-531-89701893; E-mail: zlshen88@mail.ustc.edu.cn; Jian-Hua ZHU, E-mail: jianhuazhu9@sina.com * These authors made equal contributions to this work and share first authorship.…”