Quick gas chromatographic method for determining common pesticides in musts and wines

Extraction and quantification of pesticides and metals in palm wines by HS-SPME/GC-MS and ICP-AES/MS

In this study, HS-SPME/GC-MS and ICP-AES/MS methods are presented to extract and quantify pesticides and metals in palm wines. Various parameters affecting the extraction were investigated: SPME fiber, equilibrium and extraction time, extraction temperature, salinity, and stirring, through an experimental design with 45 trials. The developed method allowed to identify 35 pesticides and quantify 29 of them, from different families of pesticides in 32 palm wine samples. Method performance was evaluated in terms of linearity, repeatability, LOD, LOQ, and accuracy. Among the 32 samples analyzed in 3 replicates, 7 pesticides were detected in 10 samples. Dichlorvos was the only pesticide detected at levels above the European maximal limits. Additionally, 10 of the 19 metals explored by ICP-AES and ICP-MS were found in all samples. Six metals were detected in different samples at levels above the European or OIV maximal limits for drinking water or wine.

Determination of azolic fungicides in wine by solid-phase extraction and high-performance liquid chromatography–atmospheric pressure chemical ionization–mass spectrometry

A method for simultaneous analysis of eight azolic fungicides: cyproconazole, diniconazole, tetraconazole, thiabendazole, flusilazole, triadimenol, triadimefon, carbendazim and the degradation product 2-aminobenzimidazole in wine samples is described. The compounds are isolated from the samples and concentrated by solid-phase extraction on polymeric cartridges. The determination is carried out by liquid chromatography with mass spectrometric detection in positive ionization and selected ion monitoring modes. The influence of parameters such as the mobile phase composition, column temperature, corona current and fragmentor voltage is studied and the proposed method is validated. Recoveries of the nine compounds added to wine samples range from 83 to 109%, with relative standard deviations below 10%. The quantitation limits are between 9 and 31 microg/L. Real wine samples are analyzed by the proposed method, also.

Stir bar sorptive extraction applied to the determination of dicarboximide fungicides in wine

The dicarboximide fungicides vinclozolin, iprodione and procymidone were analyzed in white wines using stir bar sorptive extraction (SBSE) in combination with thermal desorption-capillary GC-MS analysis (TD-cGC-MS). The method was optimized using spiked water samples in a concentration range between 0.5 and 100 microg/l. Iprodione was measured as its degradation product 3,5-dichlorophenyl hydantoin. Limits of quantification in the full scan MS mode are 0.5 microg/l for vinclozolin and procymidone and 5 microg/l for iprodione. In the ion monitoring mode, concentrations 100 times lower can be dosed. Because of wine matrix effects on the recoveries, quantification of the target fungicides in wine had to be carried out by standard addition. For the thermolabile iprodione, the accuracy of SBSE-TD-cGC-MS was verified using SBSE followed by liquid desorption and analysis by liquid chromatography-atmospheric pressure chemical ionization mass spectroscopy. Procymidone and iprodione were detected in wines in concentrations up to 65 microg/l while the highest concentration of vinclozolin detected was smaller than 3 microg/l.

Analysis of pesticide residues in wine by solid-phase extraction and gas chromatography with electron capture and nitrogen-phosphorus detection

A feasible and reproducible method for multiresidue analysis of several common pesticides, of different polarities, in wine samples is proposed. The method combines a solid-phase extraction on polymeric cartridges eluted with ethyl acetate and a gas chromatographic determination using electron capture and nitrogen-phosphorus detection. To avoid the matrix effect, previous washing of the cartridges with a mixture of water-2-propanol (90:10) and further clean-up of the extract on Florisil cartridges, together with a calibration using spiked extracts, are recommended.

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.