Determination of Type A and B Trichothecenes in Cereals by Gas Chromatography with Electron Capture Detection

Abstract

A quantitative method has been developed for determination of nonmacrocyclic trichothecenes in cereals. The mycotoxins are extracted with acetonitrile- ethyl acetate-water, and the extracts are quickly defatted with hexane and purified on a Sep- Pak Florisil cartridge. The trichothecenes are then silylated with Tri-Sil/TBT and quantitated by capillary gas chromatography with electron capture detection. High recoveries of 13 tested trichothecenes were achieved in experiments on wheat at the 250 μg/kg level. The method was also tested on barley, maize, oats, and rye with good results

Analysis of Trichothecene Mycotoxins by Gas Chromatography with Electron-Capture Detection

“…As expected, the more hydroxyl groups, the greater the sensitivity, although absence of the R15 hydroxy appeared to decrease the response (i.e., 3AD vs FAD, VER vs HT2). The fluoroacyl derivatives offer similar sensitivity for type A and B trichothecenes (based on OH groups) when using ECD (Romer et al, 1978;Cohen and Lapointe,1984;Scott et al, 1989), whereas, in comparison, the trimethylsilyl (TMS) derivatives of type B trichothecenes have greater ECD sensitivity than those of type A (Kuroda et al, 1979;Moller and Gustavsson, 1992). Furthermore, fluoroacyl derivatives are more stable to heat and less sensitive to moisture than TMS derivatives (Blau and King, 1977).…”

“…Derivatization is typically required to obtain suitable volatility and good chromatographic results. Trimethylsilylation with either flame ionization detection (FID) or electron capture detection (ECD) have been applied successfully to several trichothecenes (Kuroda et al, 1979;Chu, 1990;Moller and Gustavsson, 1992), as have fluoroacyl derivatives with ECD (Romer et al, 1978; Cohen and Lapointe, 1984;; Scott et al, 1989). The use of ECD provides considerable sensitivity to the analytical method.…”

Fusarium culmorum Infection of Barley Seedlings: Correlation between Aggressiveness and Deoxynivalenol Content

“…Defrosted replicate plant samples were pooled, dried at 40°C overnight and ground in a mortar by hand. Extraction and determination of DON was according to Möller and Gustavsson (1992) with the following modifications: the pooled plant samples weighed between 1.4 and 2.2 g (d.w.), and the volume of extraction solvent was adjusted accordingly. To promote extraction, the samples were treated ultrasonically for 30 min followed by 30 min on an overhead rotator.…”

“…Defrosted replicate plant samples were pooled, dried at 40°C overnight and ground in a mortar by hand. Extraction and determination of DON was according to Mo¨ller and Gustavsson (1992) with the following modifications: the pooled plant samples weighed between 1.4 and 2.2 g (d.w.), and Calibration curves in the range from 0.05 to 1.00 ng l1 -1 were prepared for each series of analyses (r 2 values for these lines were >0.99). DON concentrations in the plant samples were determined comparing GC/MS (gas chromatography/mass spectrometry) peak areas of samples with the calibration curves.…”

Indirect Electrochemical Detection of Type-B Trichothecene Mycotoxins

“…15 Several analytical methods have been developed to detect these toxins. The most commonly used methods include GC/ECD, 14, [16][17][18][19] TLC/MS, 20 TLC/fluorescence, [21][22][23] HPLC/UV, 14 HPLC/MS, 24,25 and GC/MS. [26][27][28] These methods require significant amounts of time associated with labor-intensive cleanup, sophisticated instrumentation, and skilled operators.…”