Automation of a clean-up procedure for determination of trichothecenes in cereals using a charcoal-alumina column

A rapid method with ultra-high-performance liquid chromatography-tandem mass spectrometry for simultaneous determination of five type B trichothecenes in traditional Chinese medicines

A speedy and selective ultra-HPLC-MS/MS method for simultaneous determination of deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-ADON), 15-ADON, nivalenol and fusarenon X in traditional Chinese medicines (TCMs) was developed. The method was based on one-step sample cleanup using reliable homemade cleanup cartridges. A linear gradient mobile-phase system, consisting of water containing 0.2% aqueous ammonia and acetonitrile/methanol (90:10, v/v) at a flow rate of 0.4 mL/min, and an Acquity UPLC HSS T3 column (100 mm x 2.1 mm, 1.8 microm) were employed to obtain the best resolution of the target analytes. [(13)C(15)]-DON was used as the internal standard to accomplish as accurate as possible quantitation. The established method was further validated by determining the linearity (R(2) > or = 0.9990), sensitivity (LOQ, 0.29-0.99 microg/kg), recovery (88.5-119.5%) and precision (RSD < or = 15.8%). It was shown to be a suitable method for simultaneous determination of DON, 3-ADON, 15-ADON, nivalenol and fusarenon X in various TCM matrices. The utility and practical impact of the method was demonstrated using different TCM samples.

Novel sampling methods for the analysis of mycotoxins and the combination with spectroscopic methods for the rapid evaluation of deoxynivalenol contamination

A novel non-destructive sampling approach is described for the identification of food matrices contaminated with deoxynivalenol and other mycotoxins. This technique is different from currently applied sampling procedures for this purpose and is based on the principle that surface material from the tested goods is collected on a filter and brought to chemical or spectroscopic analysis. This approach has been applied to several matrices and mycotoxins, with a focus on those mycotoxin-matrix combinations that are of main relevance due to current or future legislation. Tests were carried out with a facility that has been shown to be suitable to process large quantities of materials at points of transaction, such as harbour. Further experiments with a small sampling lance prototype showed that analytical results from the chemical analysis of the tested goods can be correlated with the results obtained with this novel sampling procedure.

Occurrence of deoxynivalenol (vomitoxin) in processed cereals and pulses in Turkey

The aim was to investigate the occurrence of deoxynivalenol (DON) in cereal and pulse products in Turkey. DON was detected using high-performance liquid chromatography (HPLC) with ultraviolet detection at 220 nm and positive results greater or equal to 0.60 ppm were confirmed by thin layer chromatography (TLC). An acetonitrile-water (21:4 v/v) extract of the sample was cleaned up on a column packed with alumina-Celite-charcoal (0.35 + 0.25 + 0.40 g). The detection limits for DON were 3 ng/injection (0.10 ppm) and 50 ng/spot (0.60 ppm) for HPLC and TLC, respectively. Eighty-three commercially available cereal and pulse product samples collected from markets and street bazaars were analysed. The recovery rates for boiled, pounded wheat and rice spiked with added DON (1 ppm) were 80.9% (SD 8.37, n=5) and 72.3% (3.85, n=5), respectively. DON was detected in six (8.82%) of 68 cereal and in none of 15 pulse products. The maximum detected amount was 2.67 ppm in a corn flour sample.

Liquid chromatography/tandem mass spectrometry for the identification and determination of trichothecenes in maize

A reliable, sensitive and selective liquid chromatography/tandem mass spectrometry (LC/MS/MS) method has been developed to determine four trichothecene mycotoxins (nivalenol, deoxynivalenol, fusarenon X and 3-acetyldeoxynivalenol) in maize. Sample preparation was performed by extracting the analytes with a mixture of acetonitrile and water, followed by a solid-phase extraction with Carbograph-4 cartridges as the purification step. For the LC/MS/MS analysis two interfacing systems, Turbo IonSpray (TISP) and atmospheric pressure chemical ionization (APCI), were compared in both negative and positive ion modes. LC and MS parameters were optimized to achieve better results and sensitivity. The effect of mobile phase modifiers such as ammonium acetate and formic acid on the ionization yield was also evaluated. The best results were obtained using the electrospray ionization (ESI) interface in negative ion mode and the multiple reaction monitoring mode (MRM) for the quantitation. The detection limits ranged between 10 ng/g for fusarenon X and 1.5 ng/g for deoxynivalenol. A linear working range was achieved with a standard deviation between 3 and 10% and recovery rates from the maize samples above 81%. The procedure was applied to the analysis of a set of maize samples collected from farms located in different areas of northern and central Italy. The investigated samples turned out to be contaminated primarily with deoxynivalenol and, to a minor extent, with its derivatives.

Sources of variation in the analysis of trichothecenes in cereals by gas chromatography-mass spectrometry

The sources of variation In the analysis of trichothecenes in cereals by gas chromatography mass spectrometry (GC-MS) were studied and Identified. Ways to decrease some of the variations identified are presented and discussed. The method Is validated for deoxynivalenol, nivalenol, 3-acetyldeoxynivalenol, fusarenon-X, diacetoxyscirpenol, HT-2 toxin and T-2 toxin. The general variability in the performance of the GC-MS apparatus itself, as well as derivatisation, matrix effect, injection and quantification were identified to be the sources of variation. The use of internal standards was studied in order to decrease the variation due to problems with derivatisation and the overall sample preparation. Two derivatisation reagents were compared, one of which was found to be more effective for decreasing this variation. The calibrants prepared in the cereal extract reduced the variation due to the matrix effect and thus improved the quantification. "Constant Standards" were introduced in order to detect and decrease the variation caused by injection and the apparatus itself. The validation study proved that this analytical method for trichothecenes was adequately reliable and sensitive. The relative standard deviation varied between 3-9% and the recovery between 46-90% for the different trichothecenes determined. The limit of detection for a range of trichothecenes varied from 5 μg/kg to 15 μg/kg.

Critical study of and improvements in chromatographic methods for the analysis of type B trichothecenes

Various analytical methods used in the analysis of type B trichothecenes (deoxynivalenol, nivalenol, 3- and 15-acetyldeoxynivalenol) in cereals were compared and optimised in this work. These methods use either GC-electron-capture detection (ECD) of trimethylsilyl, trifluoroacetyl and heptafluorobutyryl derivatives or HPLC with UV or photodiode array detection of analytes. A new HPLC procedure using fluorescence detection prior derivatisation with coumarin-3-carbonyl chloride has been also tested. Five extraction solvents and two solid-phase extraction cartridges (silica, Florisil) plus a especial clean-up column (MycoSep 225) were compared in order to obtain the best recovery of the mycotoxins with minimal presence of coextractives in the chromatograms. The chosen extraction solvent was a mixture of acetonitrile-water (84:16, v/v). The MycoSep 225 column was chosen as the best alternative for clean-up of grain samples. For GC-ECD analysis, derivatisation of analytes with heptafluorobutyric anhydride prior the final determination was chosen as the most suitable procedure. HPLC-photodiode array (at 221 nm) analysis was more suitable for determination of type B trichothecenes than HPLC of the fluorescent coumarin-3-carbonyl derivatives. Recoveries obtained in spiked corn, rice and wheat are reported. The utility of the proposed methodology was assayed in cereal cultures of various Fusarium strains.

Effects of diets with graded levels of naturally deoxynivalenol-contaminated oats on immune response in growing pigs

A trial was conducted to evaluate the effect of including different levels of deoxynivalenol (DON)-contaminated oats in the complete diets of growing pigs on immune response and performance. The diets contained 0.6, 1.8 and 4.7 mg DON/kg, and both restricted and ad libitum feeding were used. Performance was recorded as weight gain, feed intake, efficiency of feed utilization and carcass quality. Immune response parameters recorded included primary and secondary antibody titres after injections of five different antigens: Human serum albumin (HSA), sheep red blood cells (SRBC), paratuberculosis vaccine (MPT), tetanus toxoid (TT) and diphteria toxoid (DT). A johnin test was also performed. Lymphocyte stimulation response was measured with three different mitogens (PWM, ConA and PHA). A significant, DON dose-dependent reduction in secondary antibody response to tetanus toxoid was observed. A slightly higher mitogen response after PHA stimulation in lymphocytes from the medium and high DON groups compared to the low DON group after 9 weeks was considered inconclusive. No other indication of dose-dependent immune response inhibition or stimulation was found. Significantly reduced feed intake with increased levels of DON was observed in groups fed restricted rations according to weight, but not in animals fed ad libitum.

The effects of naturally deoxynivalenol-contaminated oats on the clinical condition, blood parameters, performance and carcass composition of growing pigs

A feeding trial with naturally deoxynivalenol (DON)-contaminated oats included in feed mixtures at graded levels was conducted in growing pigs. The DON concentrations were 0, 0.7, 1.7, and 3.5 mg/kg of complete feed mixture given ad libitum to different groups. The data recorded were feed consumption, body weight gain, slaughter weight, biochemical and haematological data including serum immunoglobulin A, clinical condition and post-mortem pathology including histopathology. Significantly decreasing body weight gain throughout the experimental period, decreased slaughter weight and reduced feed utilization efficiency were observed for the group fed a diet containing 3.5 mg/kg of DON. At the same DON concentration, there were increased liver weights and decreased concentrations of serum protein and albumin, and a temporary fall in packed blood cell volume, serum calcium and serum phosphorus. For the groups fed diets containing 1.7 and 3.5 mg/kg of DON, a statistically significant, dose-related decrease in daily feed consumption was observed. No other effects on haematological, biochemical or immunological parameters were recorded. The carcass quality was not affected in any group. It was concluded that significant effects in growing pigs may be observed at a dietary DON concentration of 1.7 mg/kg, originating from naturally contaminated oats included in a diet that was otherwise adequate and contained only minor traces of other mycotoxins.