Gas chromatography: mass spectrometry determination of trichothecene mycotoxins in commercial corn harvested in the state of São Paulo, Brazil

Abstract

Investigou-se a incidência de desoxinivalenol (DON), nivalenol (NIN), diacetoxiscirpenol (DAS) e toxinas T-2 (T2) e HT-2 (HT2) em 80 amostras de milho do estado de São Paulo/ Brasil, coletadas nos silos de duas cooperativas deste estado. As amostras foram extraídas com água/ acetonitrila e purificadas com colunas Mycosep. Após derivatização com anidrido trifluoroacético as amostras foram analisadas por cromatografia gasosa-espectrometria de massas. Os limites de detecção ficaram entre 10 ng g -1 e 40 ng g -1. NIV foi encontrada em 5 amostras e DON e NIV ocorreram simultaneamente numa das amostras. DAS, T2 e HT2 não foram detectadas. Este é o primeiro relato que mostra a prevalência de NIV sobre DON em milho do Brasil.The incidence of deoxynivalenol (DON), nivalenol (NIV), diacetoxyscirpenol (DAS), and toxins T-2 (T2) and HT-2 (HT2) in 80 samples of commercial corn harvested in the state of São Paulo, Brazil. They were collected in the silos of the two largest corn farmer's cooperatives of this state. The samples were extracted with water/acetonitrile and cleaned-up with MycoSep columns. After trifluoroacetic anhydride derivatization the samples were submitted to gas chromatography-mass spectrometry. Detection limits ranged from 10 ng g -1 to 40 ng g -1 . NIV was present in 5 samples and DON and NIV occurred simultaneously in one sample. DAS, T2 and HT2 were not detected. This is the first report that shows the prevalence of NIV over DON in corn harvested in Brazil. Keywords: corn, GC-MS, trichothecenes, deoxynivalenol, nivalenol IntroductionTrichothecenes constitute a group of toxic substances produced mainly by Fusarium among several different fungal genera.1 These compounds have in common the presence of the system 12, 13 -epoxy-trichotec-9-en in their structures.2,3 Diacetoxyscirpenol (DAS) and the toxins T2 (T2) and HT2 (HT2), deoxynivalenol (DON) and nivalenol (NIV) are among the trichothecenes with greater natural occurrence in food and feed. [4][5][6] The ingestion of feed contaminated with trichothecenes has been shown to be toxic and to cause feed refusal, emesis, diarrhea, anorexia, hematological and immunological alterations and even death. Similar symptoms have been observed in humans exposed to trichothecenes. 1,2,4,7 Trichothecenes occur in cereals worldwide 6 and contamination in corn is frequently reported. [8][9][10][11][12][13][14][15] There is little information about corn cultivated in Brazil. Prado et al. 16 found DON in about 6% of post-harvested corn samples with levels ranging from 102 to 542 ng g -1 in contaminated samples and 104 ng g -1 T2 in one sample. Oliveira et al. 17reported the presence of DON in 6% of samples of popcorn in levels ranging from 30 to 770 ng g -1 . Several methods are used to determine trichothecenes, such as thin layer chromatography, liquid chromatography, gas chromatography, and immunoassays. 7,18,19 More recently some methods have been developed using the liquid chromatography/tandem mass spectrometry for identification and determination of trichothecenes type...

Fusarium species and fumonisins associated with maize kernels produced in Rio Grande do Sul State for the 2008/09 and 2009/10 growing seasons

“…The presence of F. graminearum sensu lato at relatively lower prevalence and incidence levels in maize kernels is in agreement with a previous study in the Rio Grande do Sul State, where it was found to be the second species in prevalence in a monoculture vs. crop rotation study (Trento et al , 2011). Collectively, these results suggest that maize kernels from the southernmost region of Brazil may also be contaminated with trichothecene mycotoxins because of the presence of F. graminearum sensu lato , as has been previously shown in a few maize samples from other Brazilian regions (Milanez and Valente-Soares, 2006). …”

“…In a large spatial-scale survey and analysis of 214 maize grain samples from several locations in Brazil, 99% of the samples were contaminated with fumonisin B 1 (FB 1 ) in levels ranging between 0.2 and 6.1 μg/g (Vargas et al , 2001). More recently, trichothecene mycotoxins, especially deoxinivalenol (DON) and nivalenol (NIV), a class of mycotoxins mainly produced by members of the F. graminearum species complex, have been found in 16 and two samples, respectively, out of 80 samples of Brazilian maize grains (Milanez and Valente-Soares, 2006). …”

Natural sesquiterpenoids

“…108 GC-MS techniques have been used in the analysis of trichothecene mycotoxins in commercial corn harvested in Brazil. 109 The synthesis of four mycotoxins of this type labelled with carbon-13 and their application as internal standards in stable isotope dilution assays for their determination in foods has been described. 110 The loss of toxicity of deoxynivalenol in extruded cereal-based products has been confirmed using different types of analysis.…”

Development of a recombinant Fab-fragment based electrochemical immunosensor for deoxynivalenol detection in food samples

“…Five different sample treatment procedures (Scheme SI1) were investigated. Extracting with a solution of acetonitrile/water was studied and the possible utilization of a clean-up step, using Solid Phase Extraction (Mycosep or Bondelut cartridges) was considered (Bretz et al, 2006;Milanez and Valente-Soares, 2006). Methanol was also used as an extraction solvent followed by a Bond Elut clean-up procedure.…”