Jordi Mañes

Capillary electrophoresis for the determination of pesticide residues

Capillary electrophoresis (CE) is becoming an advantageous tool for determining pesticide residues in environmental matrices because of its simplicity and high separation efficiency. However, inadequate limits of detection (LODs) and a lack of selective detectors limit the technique. The present review gives an overview of current developments in off-column and on-column approaches to trace enrichment in analysing real samples, and summarises the determination of pesticides residues by conventional CE as well as by the emerging techniques, such as CE-mass spectrometry (MS). The usefulness of these approaches in environmental applications is documented.

Further data on the presence of Fusarium emerging mycotoxins enniatins, fusaproliferin and beauvericin in cereals available on the Spanish markets

In this work, 64 samples of cereals purchased from local markets in the Valencian community (Spain) were investigated for the presence of six emerging mycotoxins: enniatins ENs (ENA, ENA1, ENB and ENB1), beauvericin (BEA) and fusaproliferin (FUS). Samples were extracted with a mixture of water/acetonitrile (85/15, v/v) by using an Ultra-turrax homogenizer. Mycotoxins were then identified and quantified with a liquid chromatography (LC) with diode array detector (DAD). Positive samples were confirmed with an LC-MS/MS. Analytical Results showed that the frequencies of contamination of samples with ENs, BEA and FUS were 73.4%, 32.8% and 7.8%, respectively. ENA1 was the most mycotoxin found and levels ranged from 33.38 to 814.42 mg/kg. ENB levels ranged between 2.23 and 21.37 mg/kg. ENB1 levels varied from 4.34 to 45.94 mg/kg. All samples were free of ENA. BEA levels ranged from 0.51 to 11.78 mg/kg and FUS levels varied between 1.01 and 6.63 mg/kg. It could be concluded from this study that the high contamination levels found especially for ENs could be of a negative impact on the population. This is the first paper on the presence of emerging mycotoxins in cereals available in Spain.

Incidence of ochratoxin A in rice and dried fruits from Rabat and Salé area, Morocco

One hundred samples of dried fruits (20 dried raisins, 20 walnuts, 20 peanuts, 20 dried figs and 20 pistachios) and 20 samples of rice purchased from retail shops in the Rabat and Salé area in Morocco were analysed for ochratoxin A (OTA) by immunoaffinity clean-up (IAC) and liquid chromatography (LC) with fluorescence detection. The limit of quantification (LOQ) (S/N = 10:1) of OTA was 0.02 ng g−1 in rice, 0.03 ng g−1 in pistachio, peanut and walnut, and 0.03 ng g−1 in dried raisins and dried figs. The incidences of occurrence of OTA in dried raisins, walnuts, peanuts, dried figs and rice were 30, 35, 25, 65 and 90%, respectively. Analytical results showed that pistachio samples contained no detectable OTA, but concentrations ranged from 0.02 ± 0.01 to 32.4 ± 2.10 ng g−1 in rice, from 0.10 ± 0.05 to 2.36 ± 0.75 in peanut, from 0.03 ± 0.01 to 1.42 ± 0.45 in dried figs, from 0.05 ± 0.02 to 4.95 ± 0.02 in dried raisins, and from 0.04 ± 0.01 to 0.23 ± 0.05 in walnuts. The results also showed that 15% of the total number of rice samples analysed exceeded the 2002 regulatory limit set by European Union regulations for cereals. This is the first report on the occurrence of OTA in dried fruits and rice available in Morocco.

Multi-mycotoxin analysis in wheat semolina using an acetonitrile-based extraction procedure and gas chromatography-tandem mass spectrometry.

A new analytical method for the rapid and simultaneous determination of ten mycotoxins including patulin, zearalenone and eight trichothecenes (nivalenol, fusarenon-X, diacetoxyscirpenol, 3-acetyl-deoxynivalenol, neosolaniol, deoxynivalenol, T-2 and HT-2) in wheat semolina has been developed and optimized. Sample extraction and purification were performed with a modified QuEChERS-based (acronym of Quick, Easy, Cheap, Effective, Rugged and Safe) procedure and determined by gas chromatography (GC) coupled to triple quadrupole instrument (QqQ). This is the first paper on the application of GC-QqQ-MS/MS to analysis of mycotoxins. Careful optimization of the gas chromatography-tandem mass spectrometry parameters was achieved in order to attain a fast separation with the best sensitivity allowing a total run time of 16 min. The validation was performed by analyzing recovery samples at three different spiked concentrations, 20, 40 and 80 μg kg(-1), with four replicates (n=4) at each concentration. Recoveries ranged from 74% to 124% and the intra-day precision and inter-day precision, expressed as relative standard deviation, were lower than 13% and 17%, respectively for all studied compounds, except for zearalenone. Limits of quantification (LOQ) were lower than 10 μg kg(-1) for all studied mycotoxins. Eight concentration levels were used for constructing the calibration curves which showed good linearity between LOQ and 100 times LOQ concentration levels (linear range). Matrix-matched calibration for applying the method in routine analysis is recommended for reliable quantitative results. The method validated was successfully applied to fifteen wheat semolina samples detecting occurrence of mycotoxins at concentrations below the maximum permissible level.

Factors affecting the presence of ochratoxin A in wines.

Ochratoxin A (OTA) are synthesized mainly by different species of Aspergillus and Penicillium being its human toxicological effects reflected in different countries due to the consumption of different foods and beverages such as red, white, rose, and special wines. This review presents an overview of the direct (meteorological conditions, grape cultivation, and wine-making techniques) and indirect (latitude, year of production, use of pesticides, presence of spoilage microorganisms, conditions of storage of the harvested grapes, type of maceration, and conditions of fermentation), factors affecting the presence of OTA in wines.

Evaluation of matrix solid-phase dispersion (MSPD) extraction for multi-mycotoxin determination in different flours using LC–MS/MS

An existing matrix solid-phase dispersion (MSPD) method for aflatoxins (AFs) and ochratoxin A (OTA) extraction was extended by further 14 mycotoxins. After it careful optimization, this method was applied to determine the occurrence of these mycotoxins on commercial flour samples (with different cereals composition) collected from local markets. In a total of 49 samples investigated, 9 mycotoxins were identified. Nivalenol (NIV) and Beauvericin (BEA) were the mycotoxins found most frequently. The samples that presented major contamination were wheat flours and bakery preparations. Despite of the great number of positives finding, only one wheat flour sample exceeded the maximum limits (ML) for OTA established by the European Union (EU). However, it would be interesting to calculate the total ingest of these mycotoxins along the years.

Evaluation of beauvericin and enniatins in Italian cereal products and multicereal food by liquid chromatography coupled to triple quadrupole mass spectrometry

In this study, 48 multicereal baby foods samples including 25 of pasta and 23 of multicereal baby foods from supermarkets of Campania region (Italy) were analysed for evaluating the presence of beauvericin (BEA) and enniatins (ENs) A, A1, B, B1 and B4. Subsequently to evaluate the risk exposure of Italian population and infant population over the consumption of pasta or multicereal baby food, was, respectively, evaluated. For the above mentioned evaluation, a method developed in our laboratory by liquid chromatography tandem mass spectrometry was used. A liquid phase dispersion procedure was optimised for the simultaneous extraction of BEA and the five ENs from multicereal baby food samples and pasta. The main parameters affecting extraction yield and selectivity, extraction solvent were evaluated. The method was validated by analysis for pasta and multicereal baby food samples fortified at different concentration levels (from 0.5 to 20μg/kg). Average recoveries (n=5) ranged from 85% to 99% with relative standard deviation lower than 13%. Limits of quantification (LQs) for both matrices ranged from 1 to 10μg/kg. Analytical results showed that the occurrence of BEA, ENA, ENA1, ENB, ENB1 and ENB4 in analysed pasta and multicereal baby food samples were below 68% and 74%, respectively. ENB was the mycotoxin most found and levels in pasta and baby food ranged from <LQ to 106 and from <LQ to 1100μg/kg, respectively. It was observed a high incidence (70.3%) and high contamination levels (<1100μg/kg) of these mycotoxins in multicereal baby food and its intakes could represent a risk for the infant population (estimated daily intake <7.23μg/kgbw/day).

Enterotoxigenic staphylococci and their toxins in restaurant foods

Abstract This review presents an overview of the enterotoxigenic staphylococci and their toxins in restaurant foods, with special reference to the characteristics of these micro-organisms and their enterotoxins. Furthermore, this paper reviews the staphylococcal food poisoning outbreaks, principal sources of contamination and food safety measures that can be applied to eliminate the presence of enterotoxigenic staphylococci in restaurant foods.

Occurrence of Fusarium mycotoxins in Italian cereal and cereal products from organic farming

In the present study, the occurrence of eighteen mycotoxins, nine trichothecenes (deoxynivalenol, 3-acetyl-deoxynivalenol, 15-acetyl-deoxynivalenol, nivalenol, neosolaniol, diacetoxyscirpenol, fusarenon-X, T-2 toxin and HT-2 toxin), three zearalenones (zearalenone, α-zearalenol and β-zearalenol), and six emergent mycotoxins, beauvericin and five enniatins (A, A1, B, B1 and B4), was monitored in different Italian organic cereals and cereal products by using a liquid chromatography coupled to triple quadrupole mass spectrometry method. A total of 93 organic cereal samples (wheat, barley, rye and oat) were collected from Italy. Limits of quantification ranged from 5 to 15 μg/kg. 80% of analyzed samples contained mycotoxins. The occurrence was 33%, 6.5%, 2%, 27%, 7%, 10% and 43% for deoxynivalenol, HT-2, T-2, nivalenol, zearalenone, beauvericin and enniatins, respectively. The major mycotoxin found was enniatin B4; it was detected in 40% of all analyzed samples and its levels ranged from 5.7 to 284.2 μg/kg. Risk assessment was evaluated by EDI calculations which were lower than TDI for all legislated Fusarium mycotoxins.

Determination of trichothecenes and zearalenones in grain cereal, flour and bread by liquid chromatography tandem mass spectrometry

Although analytical methods have been already reported for legislated mycotoxins as trichothecenes and zearalenone (ZON) separately, we describe the optimization of a simple and rapid multimycotoxin method for the determination of a total of 12 mycotoxins simultaneously, nine trichothecenes (NIV, DON, FUS-X, DAS, 15-AcDON, 3-AcDON, NEO, HT-2, T-2 T2), and zearalenone and its metabolites (ZON, α-ZOL, β-ZOL), of different origin (wheat, oat, barley and spelt) and in three different products where these substance can be present (grain, flour and bread) reach the food chain and cause toxic effect either in humans or animals. The extraction procedure was based on a mixture of acetonitrile/water (84/16, v/v), which provided the highest recoveries and the lowest matrix effect. DON-d1 was used as internal standard (I.S.) which helped to compensate the significant matrix effect observed for some matrices, and to obtain high success in the method validation and to reach the parameters compiled in Commission Decision, 2002/657/EC. Analytes were determinate by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Relative recoveries obtained were higher than 70% for the studied mycotoxins the four cereal. Good linearity (r(2)>0.992) was obtained and quantification limits (2.5-25 ng/g) were below European regulatory levels. Repeatability, expressed as relative standard deviation, was always lower than 11%, whereas interday precision was lower than 11% for the developed method.