Simultaneous determination of type-A and type-B trichothecenes in barley samples by GC-MS

A validated method for the simultaneous determination of eight type-A and type-B trichothecenes in barley has been applied to the analysis of 44 samples from the 2007 harvest in Navarra (Spain). The procedure included simultaneous extraction of trichothecenes with acetonitrile and water (84:16), clean up with Multisep columns, derivatization of the extract and GC-MS analysis. During method validation, selectivity, linearity, precision and accuracy, limits of detection and quantification and recovery were evaluated. Recovery ranged from 92.0 to 101.9% (RSD < 15%), except for nivalenol (NIV) (63.1%), and the limits of detection and quantification ranged from 0.31 to 3.87 mu g kg(-1) and from 10 to 20 mu g kg(-1), respectively. The higher occurrence was found for deoxynivalenol (DON) (89% of the samples), although at concentrations below the maximum permitted level. The calculated dietary intakes of DON, NIV and the sum of T-2 and HT-2 were below the TDI values proposed. Two or more trichothecenes were present in 41% of the samples and so, the mycotoxin co-occurrence, and therefore synergic or additive effects, should be taking into account when determining permitted levels or risk assessment

Validation of a liquid chromatography method for the simultaneous quantification of ochratoxin A and its analogues in red wines

A validated high-performance liquid chromatography (HPLC) method with fluorescence detection for the simultaneous quantification of ochratoxin A (OTA) and its analogues (ochratoxin B (OTB), ochratoxin C (OTC) and methyl ochratoxin A (MeOTA)) in red wine at trace levels is described. Before their analysis by HPLC-FLD, ochratoxins were extracted and purified with immunoaffinity columns from 50 mL of red wine at pH = 7.2. Validation of the analytical method was based on the following parameters: selectivity, linearity, robustness, limits of detection and quantification, precision (within-day and between-day variability), recovery and stability. The limits of detection (LOD) in red wine were established at 0.16, 0.32, 0.27 and 0.17 ng L-1 for OTA, OTB, MeOTA and OTC, respectively. The limit of quantification (LOQ) was established as 0.50 ng L-1 for all of the ochratoxins. The LOD and LOQ obtained are the lowest found for OTA in the reference literature up to now. Recovery values were 93.5, 81.7, 76.0 and 73.4% for OTA, OTB, MeOTA and OTC, respectively. For the first time, this validated method permits the investigation of the co-occurrence of ochratoxins A, B, C and methyl ochratoxin A in 20 red wine samples from Spain

Co-occurrence of aflatoxins, ochratoxin A and zearalenone in barley from a northern region of Spain

One-hundred and twenty-three barley samples from a region of Spain (Navarra) were analysed in order to evaluate the possible co-occurrence of aflatoxins (AFB1, AFG1, AFB2 and AFG2), ochratoxin A (OTA) and zearalenone (ZEA). The results indicated that 80% of the samples presented detectable, although very low levels, of two or more mycotoxins. The most frequent combinations were AFB1 and OTA; AFB1, ZEA and OTA; and AFB1 and ZEA. In general, the statistical study did not show significant differences between levels or incidence for the mycotoxins in different years of harvest, variety of barley, farming or origin. The calculated values for daily intake were low and the risk to consumers could be assumed to be very low. However, the co-occurrence of several mycotoxins, and therefore synergic or additive effects, should be taken into account when determining permitted levels or risk assessment

Co-occurrence of type-A and type-B trichothecenes in barley from a northern region of Spain

In this survey, 123 barley samples from a northern region of Spain (Navarra) have been analyzed for co-occurrence of eight type-A and type-B trichothecenes (DON, NIV, 3-ADON, 15-ADON, FUS-X, T-2, HT-2 and DAS). Samples were classified according to place and year of harvest (2007 and 2008), type of farming (organic or traditional) and variety of barley. The rains during anthesis had a great influence on the trichothecene levels, observing higher contaminations in samples collected during 2008. In addition, type-A trichothecenes tend to be more present in cooler areas, while type-B appears more often in warmer regions. The type of farming has not led to significant differences in mycotoxins levels, although a trend toward higher incidence and contamination in traditional samples has been observed. On the other hand, it was observed that Pewter, the favorite barley variety for the malting industry in Spain, has been the most susceptible to contamination with trichothecene

Validation of a UHPLC-FLD method for the simultaneous quantification of aflatoxins, ochratoxin A and zearalenone in barley

A fast and simple UHPLC-FLD method has been developed for the simultaneous determination in barley of aflatoxins (B1, G1, B2 and G2), ochratoxin A (OTA) and zearalenone (ZEA), some of the most important mycotoxins due to their toxicity and occurrence. The procedure is based on the extraction of the six mycotoxins with a mixture of acetonitrile and water, and the purification of the extract with immunoaffinity columns before analysis. Detection of AFB1 and AFG1 is improved using a photochemical reaction. The method has been validated with satisfactory results. Limits of detection were 340 ng kg-1 for ZEA, 13 ng kg-1 for OTA and varied from 0.5 to 15 ng kg-1 for aflatoxins. Recovery percentages were between 78.2 and 109.2%. After being validated, the method has been successfully applied to 20 barley samples cultivated in a region of northern Spain (Navarra)

Co-occurrence of aflatoxins, ochratoxin A and zearalenone in breakfast cereals from spanish market

Forty-six breakfast cereal samples from the Spanish market have been analyzed for the occurrence of aflatoxins (AFB1, AFG1, AFB2 and AFG2), ochratoxin A (OTA) and zearalenone (ZEA). According to the results, 9% of the samples were contaminated with AFB1 although no sample exceeded the LOQ (0.2 μg kg-1), and no sample presented detectable levels of the other aflatoxins (AFB2, AFG1 and AFG2). Zearalenone and OTA contaminated 48 and 39% of the samples, respectively, with mean values of the samples having quantification levels of 25.40 and 0.37 μg kg-1, respectively. The co23 occurrence of OTA and ZEA was observed in 28% of the samples. Aflatoxin B1 appeared only in the corn-based breakfast cereals, whereas ZEA and OTA showed the highest contamination rates in the samples containing wheat and wheat and rice, respectively. No sample of high-fiber content was contaminated with AFB1, whereas OTA and ZEA occurred with higher incidence in high-fiber content samples. Moreover, the daily exposure to AFB1, OTA and ZEA is discussed

Validation of a UHPLC-FLD analytical method for the simultaneous quantification of aflatoxin B1 and ochratoxin a in rat plasma, liver and kidney

A rapid and simple method for the simultaneous quantification of AFB1 and OTA in rat plasma, liver and kidney by UHPLC-FLD has been successfully validated according to the following criteria: selectivity, stability, linearity, precision, accuracy, recovery, robustness and limits of quantification and detection. The extraction method, calibration curves and chromatographic conditions are common for the three matrices. Plasma and homogenized tissue samples (100 μL) were extracted with acetonitrile-formic acid mixture (99:1) (300 μL). Chromatographic separation was performed with a mixture of water and acetonitrile:methanol (50:50), both acidified with 0.5% of formic acid using a gradient profile. The method avoids the use of immunoaffinity columns and allows reduction of sample and solvent volumes as well as toxic wastes. The detection is based on a photochemical reaction which enhances the AFB1 response without affecting the OTA signal before reaching the fluorescent detector. The mycotoxin recovery for each matrix was very efficient, between 93% and 96% for AFB1 and between 94% and 96% for OTA. For both mycotoxins the LOQs were 2 μg/L in plasma and 8 μg/kg in liver and kidney. The method has successfully been applied to rat samples after a single oral administration of a mixture of AFB1 and OTA and it could be a useful tool in toxicokinetic and toxicological studies

Simultaneous determination of type-A and type-B trichothecenes in barley samples by GC-MS

A validated method for the simultaneous determination of eight type-A and type-B trichothecenes in barley has been applied to the analysis of 44 samples from the 2007 harvest in Navarra (Spain). The procedure included simultaneous extraction of trichothecenes with acetonitrile and water (84:16), clean up with Multisep columns, derivatization of the extract and GC-MS analysis. During method validation, selectivity, linearity, precision and accuracy, limits of detection and quantification and recovery were evaluated. Recovery ranged from 92.0 to 101.9% (RSD < 15%), except for nivalenol (NIV) (63.1%), and the limits of detection and quantification ranged from 0.31 to 3.87 mu g kg(-1) and from 10 to 20 mu g kg(-1), respectively. The higher occurrence was found for deoxynivalenol (DON) (89% of the samples), although at concentrations below the maximum permitted level. The calculated dietary intakes of DON, NIV and the sum of T-2 and HT-2 were below the TDI values proposed. Two or more trichothecenes were present in 41% of the samples and so, the mycotoxin co-occurrence, and therefore synergic or additive effects, should be taking into account when determining permitted levels or risk assessment

Co-occurrence of mycotoxins in Spanish barley: A statistical overview

In this paper, a statistical overview of the simultaneous presence of 14 mycotoxins in Spanish barley is presented. The co-occurrence of more than two mycotoxins has been observed in 95% of the samples. From a descriptive standpoint, the results show that the most common combinations were AFB1, OTA and DON (29%), and AFB1, OTA, DON and ZEA (26%), although other combinations could also occur. However, the statistical study determined that other associations had a higher impact or importance. Four factors or combinations of variables could explain the 63% of variability found for the samples. These factors were the associations of: type-B trichothecenes and DAS; type-A trichothecenes and NIV; AFB1, AFG1 and ZEA; and AFB2 and AFG2. The toxin-producing fungi and environmental conditions have been essential in explaining the associations between the toxins

Co-occurrence of aflatoxins, ochratoxin A and zearalenone in barley from a northern region of Spain

One-hundred and twenty-three barley samples from a region of Spain (Navarra) were analysed in order to evaluate the possible co-occurrence of aflatoxins (AFB1, AFG1, AFB2 and AFG2), ochratoxin A (OTA) and zearalenone (ZEA). The results indicated that 80% of the samples presented detectable, although very low levels, of two or more mycotoxins. The most frequent combinations were AFB1 and OTA; AFB1, ZEA and OTA; and AFB1 and ZEA. In general, the statistical study did not show significant differences between levels or incidence for the mycotoxins in different years of harvest, variety of barley, farming or origin. The calculated values for daily intake were low and the risk to consumers could be assumed to be very low. However, the co-occurrence of several mycotoxins, and therefore synergic or additive effects, should be taken into account when determining permitted levels or risk assessment