Gj. Soleas et al., Assay of ochratoxin A in wine and beer by high-pressure liquid chromatography photodiode array and gas chromatography mass selective detection, J AGR FOOD, 49(6), 2001, pp. 2733-2740
To routinely assay the concentrations of ochratoxin A (OTA) in wines and be
ers, two new methods were developed and evaluated. The first utilized solid
-phase extraction on a C-18 cartridge to achieve a 100-fold sample concentr
ation followed by high-performance liquid chromatography on a Cls column wi
th gradient elution and quantitation at 333 nm by means of a photodiode arr
ay detector. Positive confirmation can be carried out by purity and match-f
actor analysis as well as peak shift following esterification with BF3. Tot
al run time is 28 min. The limits of detection (LOD) and quantitation (LOQ)
are 0.05 and 0.10 mug/L, respectively. Recovery and imprecision-ranged fro
m 83 to 94% and from 4.0 to 8.9%, respectively. With a throughput of 35 ass
ays 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 valu
es between 0.1 and 0.2 mug/L) and 107 beers (2 of which gave values between
0.05 and 0.1 mug/L): OTA was detected more frequently in red than white wi
nes, with the highest incidence in red wines from Spain and Argentina. Ther
e was no association between OTA and country of origin or beverage type amo
ng the beers analyzed. The second method utilized gas chromatography with m
ass selective detection monitoring eight specific ions, preceded by extract
ion in dichloromethane and derivatization with bis[trimethylsilyl]trifluoro
acetamide. LOD and LOQ were 0.1 and 2 mug/L, respectively; recovery and imp
recision 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 greater than or equal to0.1 mug/L.