Iprodione content of wines: where do we draw the line?

Factors Affecting the Presence of Ochratoxin A in Wines

Ochratoxin A (OTA) are synthesized mainly by different species of Aspergillus and Penicillium being its human toxicological effects reflected in different countries due to the consumption of different foods and beverages such as red, white, rose, and special wines. This review presents an overview of the direct (meteorological conditions, grape cultivation, and wine-making techniques) and indirect (latitude, year of production, use of pesticides, presence of spoilage microorganisms, conditions of storage of the harvested grapes, type of maceration, and conditions of fermentation), factors affecting the presence of OTA in wines.

Assay of ochratoxin A in wine and beer by high-pressure liquid chromatography photodiode array and gas chromatography mass selective detection

To routinely assay the concentrations of ochratoxin A (OTA) in wines and beers, two new methods were developed and evaluated. The first utilized solid-phase extraction on a C(18) cartridge to achieve a 100-fold sample concentration followed by high-performance liquid chromatography on a C(18) column with gradient elution and quantitation at 333 nm by means of a photodiode array detector. Positive confirmation can be carried out by purity and match-factor analysis as well as peak shift following esterification with BF(3). Total run time is 28 min. The limits of detection (LOD) and quantitation (LOQ) are 0.05 and 0.10 microg/L, respectively. Recovery and imprecision ranged from 83 to 94% and from 4.0 to 8.9%, respectively. With a throughput of 35 assays per working day, this method is ideal for routine OTA analysis. It was used to survey the concentrations of OTA in 942 wines (2 of which gave values between 0.1 and 0.2 microg/L) and 107 beers (2 of which gave values between 0.05 and 0.1 microg/L). OTA was detected more frequently in red than white wines, with the highest incidence in red wines from Spain and Argentina. There was no association between OTA and country of origin or beverage type among the beers analyzed. The second method utilized gas chromatography with mass selective detection monitoring eight specific ions, preceded by extraction in dichloromethane and derivatization with bis[trimethylsilyl]trifluoroacetamide. LOD and LOQ were 0.1 and 2 microg/L, respectively; recovery and imprecision were 69-75 and 9.0-11.1%, respectively. The method is not suitable for routine quantitation but is potentially useful as a confirmatory tool for samples with OTA > or =0.1 microg/L.

Multiresidue analysis of seventeen pesticides in wine by gas chromatography with mass-selective detection

We have developed a multiresidue method permitting the simultaneous quantitation of 17 pesticides in wine: dicloran, dimethoate, diazinon, chlorpyrifos-methyl, vinclozolin, carbaryl, methiocarb, dichlofluanid, parathion-ethyl, triadimefon, procymidone, myclobutanil, iprodione, imidan, dicofol, phosalone and azinphos-methyl. Solid-phase extraction of 0.5 ml of wine sample is followed by direct injection of 1 microl of the eluent onto a DB-5 MS gas chromatographic column followed by mass-selective detection using one target and two qualifier ions for each pesticide. The extraction and injection steps are carried out with automatic instrumentation. Good resolution of all compounds was achieved with a run-time approximating 23 min. Detection and quantitation limits were around 2 microg/l and 10 microg/l, respectively, with linear calibration curves up to 3 mg/l for most constituents. Recovery in half the compounds was >90%, and >80% in most of the remainder. Imprecision (relative standard deviation) was <10% for most pesticides and <18% in all. Further analytes can be added to the repertoire without difficulty. The method merits consideration together with four other multiresidue methods now available that offer similar analytical characteristics, slower run-times, and a different selection of analytes.