Solid-phase microextraction and sample stacking micellar electrokinetic chromatography for the analysis of pesticide residues in red wines

Abstract This review presents the application of carbon nanotubes as sorbent materials in the analysis of pesticide residues in fruits and vegetables. The advantages, limitations, and challenges of carbon nanotubes, with respect to their use in analytical chemistry, are presented. The efficiency of their application as extraction sorbent materials (in terms of LOD, LOQ, linearity, relative recovery, and RSD) in SPE, solid-phase microextraction, multi-plug filtration clean-up, matrix solid-phase dispersion, and the quick, easy, cheap, effective, rugged and safe method is reported. The synthesis, functionalization, purification, and characterization methods of carbon nanotubes are also discussed.

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Determination of Regularly Distributed Plant Protectants in Raw and Drinking Waters, Using a Multiresidue Method with Cyclodextrin-Modified Micellar Electrokinetic Chromatography

Journal of AOAC International ◽

10.1093/jaoac/82.6.1510 ◽

1999 ◽

Vol 82 (6) ◽

pp. 1510-1522 ◽

Cited By ~ 3

Author(s):

Hanno Stutz ◽

Hans Malissa

Keyword(s):

Environmental Protection Agency ◽

Micellar Electrokinetic Chromatography ◽

Solid Phase ◽

Tap Water ◽

Sodium Dodecyl ◽

Electrokinetic Chromatography ◽

The European Union ◽

Multiresidue Method ◽

Drinking Waters ◽

Wide Range

Abstract Eighteen plant protectant compounds were separated and determined by cyclodextrin-modified micellar electrokinetic chromatography (MEKC) in a multiclass/multiresidue method. The pesticides included are those dispersed in the greatest amounts today over agricultural acreage, and they represent 8 different classes of compounds (azoles, benzoic acids, chloroacetanilides, phenoxy acids, phenylureas, sulfonylureas, thiocarbamates, and triazines) covering a wide range of chemical reactivities and physicochemical properties. A 500 mL sample of tap water is preconcentrated by solid-phase extraction (SPE) with 300 mg combined polystyrene-divinylbenzene and methacrylate macroporous resins. Trapped analytes are eluted collectively with diethyl ether. Concentration and solvent change yield 250 μL of an acetone “concentrate,” which is further worked up and concentrated 1:10 to produce the MEKC injection solution containing 10 mmol/L sodium dodecyl sulfate (SDS) surfactant. For MEKC,2 phosphate/SDS buffer systems were designed, each allowing complete separation of all pesticides in a single run. Sensitivity was enhanced by a self-etched bubble cell and an injection procedure which employs stacking at reversed polarity. The ability of MEKC to determine plant protectants in raw and drinking waters at the 0.1 μg/L level, as demanded by the guidelines of the European Union, was demonstrated with spiked tap waters. Recoveries were between 75 and 110%, and limits of quantification, evaluated as method detection limits according to guidelines of the U.S. Environmental Protection Agency, ranged between 0.03 and 0.10 μg/L. The precisions of the relative migration times were all below 0.5%.

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