Rapid determination of fungicides in fruit juices by micellar electrokinetic chromatography: use of organic modifiers to enhance selectivity and on-column high-salt stacking to improve sensitivity.
A rapid, reliable method for the multiresidue analysis of eight commonly used fungicides by micellar electrokinetic chromatography (MEKC) was developed. Excellent separation of the eight fungicides (carbendazim, metalaxyl, captan, procymidone, folpet, captafol, vinclozolin and iprodione) is achieved within about 10 min by using optimized electrophoretic conditions that include the addition of a mixture of organic modifiers to the running buffer for improved resolution. The sensitivity of the method is enhanced by using an enrichment step that involves on-column high-salt stacking. Limits of detection in the microgram-per-liter region and relative standard deviations from 2.1 to 5.9% are thus obtained for the fungicides without detracting from peak resolution. These results reveal that the high-salt stacking method provides highly improved sensitivity and enables highly flexible adjustment of the selectivity of the separation method. Also, the method surpasses other stacking alternatives used in MEKC and affords routine analyses of fruit juice containing fungicides at trace levels following a straightforward sample treatment. The robustness of the high-salt stacking method as demonstrated in this work makes MEKC methods involving stacking procedures an attractive choice for routine analyses.
Department of Analytical Chemistry and Ecology, Faculty of Sciences, University of Córdoba, Spain.
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Molina
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Silva
D000433:1-Propanol; D019840:2-Propanol; D000097:Acetonitriles; D000409:Alanine / Q000031:analogs & derivatives / Q000032:analysis; D000620:Aminoimidazole Carboxamide / Q000031:analogs & derivatives* / Q000032:analysis; D000643:Ammonium Chloride; D001562:Benzimidazoles / Q000032:analysis; D001643:Bridged Bicyclo Compounds / Q000032:analysis; D002021:Buffers; D000440:Butanols; D002215:Captan / Q000031:analogs & derivatives* / Q000032:analysis; D002219:Carbamates; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D053138:Cyclohexenes; D000431:Ethanol; D019855:Ethylene Glycol; D005638:Fruit; D005659:Fungicides, Industrial / Q000032:analysis*; D006827:Hydantoins; D006863:Hydrogen-Ion Concentration; D000432:Methanol; D015394:Molecular Structure; D009566:Nitrates; D010080:Oxazoles / Q000032:analysis; D010797:Phthalimides / Q000032:analysis; D012680:Sensitivity and Specificity; D012965:Sodium Chloride; D013431:Sulfates; D013997:Time Factors; D014508:Urea
D000097:Acetonitriles; D001562:Benzimidazoles; D001643:Bridged Bicyclo Compounds; D002021:Buffers; D000440:Butanols; D002219:Carbamates; D053138:Cyclohexenes; D005659:Fungicides, Industrial; D006827:Hydantoins; D009566:Nitrates; D010080:Oxazoles; D010797:Phthalimides; D013431:Sulfates; D000643:Ammonium Chloride; C028175:metalaxyl; C031512:potassium sulfate; D000620:Aminoimidazole Carboxamide; D000431:Ethanol; D012965:Sodium Chloride; C040507:isobutyl alcohol; C031618:sodium nitrate; D014508:Urea; D000433:1-Propanol; C001614:captafol; C035988:procymidone; D002215:Captan; D019855:Ethylene Glycol; C006698:carbendazim; C025643:vinclozolin; D019840:2-Propanol; D000409:Alanine; C033148:iprodione; C005020:folpet; D000432:Methanol; C032159:acetonitrile