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Multiresidue analysis of pesticides in pollen by pressurized liquid extraction and gas chromatography mass spectrometry
Abstracts / Toxicology Letters 196S (2010) S37–S351
The 69% of the samples were positive, and the maximum level was recovered in corn (6.8 ppm). The percentages of positive samples were 95%, 63%, and 44% in corn, wheat and soya respectively. DON was not detected in sunflower flour. DON concentrations in corn vary between 0.4 and 6.8 ppm, in wheat between 0.85 and 4.6 ppm, in soya between 0.9 and 3.5 ppm. In order to identify the causal agent of DON accumulation in soya, contamination of seed by Fusarium species was investigated. A total of 200 seeds were surface sterilized. One hundred were directly plated on selective Fusarium media. The other 100 seeds were first grinded and then distributed in Fusarium selective agar plates. A total of 20 Fusarium isolates were obtained. Morphological species determination was confirmed by EF-1á sequencing by sequence comparison using the Fusarium database. No known DON producing species was detected. Fusarium verticilliodes was the most recurrent species therefore presence of other Fusarium toxin can be expected. Further isolation attempts are in progress. doi:10.1016/j.toxlet.2010.03.1082
P309-049 Multiresidue analysis of pesticides in pollen by pressurized liquid extraction and gas chromatography mass spectrometry H. Berrada 1 , C. Juan 2 , G. Font 1 Universidad de Valencia, Spain, 2 Centro Superior de Investigaciones en Salud Pública, Spain
1
Pesticides are extensively used to protect food against pests and diseases. However, they can remain in food causing some adverse effects. Thus, it is important to analyze and monitor pesticides to investigate the relationship between exposure and health risks. The pollen is an important product consumed as a dietary supplement by humans due to its high contents of nutrients. Pollen can be also important source of pollutants and pesticides residues used widely in agriculture. A simple method for the simultaneous determination of 17 pesticides in pollen has been developed using pressurized liquid extraction (PLE) and gas chromatography–mass spectrometry (GC–MS). Pollen (5 g) was dispersed in extracting phase C (18), and this mixture was introduced into a stainless steel extraction cell which was positioned in the pressurized liquid extraction (PLE) system ASE 200. The pressurized liquid extraction operational parameters were optimized and no precipitating protein and removing fat steps were required. Pesticides were subsequently eluted and determined by gas chromatography with electron impact mass spectrometric detection in the selected ion monitoring mode (GC–MS-SIM) of three fragment ions to provide a high degree of sensitivity and specificity. Spiked blank pollen samples were used for matrix-matched calibration standard to eliminate the matrix effect observed in the chromatographic determination. Recovery studies were performed at 50, 100, and 250 g/kg fortification levels for each pesticide, and the recoveries obtained were >65% with relative standard deviations of <20%. Good resolution of the pesticide mixture was achieved in approximately 45 min. The detection limits of the method ranged from 5 to 15 g/kg for the different pesticides studied. The developed method is linear over the range assayed, 25–200 g/kg, with determination coefficients >0.996. The proposed method was applied to the analysis of pesticides in pollen samples collected at Valencia markets. doi:10.1016/j.toxlet.2010.03.1083
S343
P309-050 Development and validation of a liquid chromatography tandem mass spectrometry method for the analysis of macrolides in honey H. Berrada 1 , C. Juan 2 , C. Igualada 2 , G. Font 1 1
Universidad Valencia, Spain, 2 Centro Superior de Investigaciones en Salud Pública, Generalitat Valenciana, Valencia, Spain The macrolide residues in honey are a potential health risk for consumers because of allergic reactions. However, due to the lack of macrolide’s MRL in Europe for antibiotic residues in honey the limit of decision of the best available analytical method determine whether residue levels are considered tolerable or not, which somehow it implies the development of very sensitive analytical methods. Nonetheless, the Community Reference Laboratories (CRLs) have suggested a minimum required performance limit (MRPL) to improve the performance of analytical methods in residue control. For honey the CRLs has suggested MRPL for only two macrolides, tylosin and erythromycin are 20 g/kg. A reproducible, sensitive and selective analytical method was developed and validated by liquid chromatography tandem mass spectrometry (LC–MS/MS) for the analysis of six macrolides in honey: erythromycin, spiramycin (the sum of I, II, III), tylosin A, B, C, D (tylosin A, desmycosin, macrocin, relomycin, respectively), josamycin, tilmicosin, lincomycin and roxithromycin was used as internal standard. The method consisted on a basic extraction (pH:10) with trisodium phosphate 12-hidrate 0.1 M, followed by centrifugation and clean up step on SPE cartridge. The eluted residue was analyzed by LC–MS/MS using ESI source in positive ion mode. Method validation was achieved in honey according to the criteria laid down in the Commission Decision 2002/657/EC and decision limit (CCá) detection capabilities (CCâ), accuracy and precision (repeatability and within lab reproducibility) were calculated. CCá were below the MRPL suggested by CRLs, for all the studied macrolides in honey and a successful application for the analysis residue control of these macrolides in different honey samples was reached. doi:10.1016/j.toxlet.2010.03.1084
P309-051 Occurrence of ochratoxin A in foods commonly consumed in Turkey S. Ozden, A.S. Akdeniz, B. Alpertunga Istanbul University, Faculty of Pharmacy, Department of Pharmaceutical Toxicology, Istanbul, Turkey Ochratoxin A (OTA) is a mycotoxin produced by several species of Aspergillus and Penicillium species. OTA contaminates in a variety of food products, resulting in chronic human exposure. Tarhana, a traditional fermented and dried yoghurt cereal food, is an important component of the daily diet in Turkey. This study was undertaken to determine the presence of OTA in tarhana from Turkey. For this purpose, 83 samples of different types of tarhana were collected during 2008–2009 years. The samples were extracted using methanol in NaHCO3 (3%, w/v) (70:30, v/v) solution followed by immunoaffinity clean up. The determination was carried out by high-performance liquid chromatography equipped with fluorescence detector. The detection limit of OTA was 0.05 ng/g and OTA identity was confirmed by methyl ester formation. The whole procedure was simple and fast if compared with
The 69% of the samples were positive, and the maximum level was recovered in corn (6.8 ppm). The percentages of positive samples were 95%, 63%, and 44% in corn, wheat and soya respectively. DON was not detected in sunflower flour. DON concentrations in corn vary between 0.4 and 6.8 ppm, in wheat between 0.85 and 4.6 ppm, in soya between 0.9 and 3.5 ppm. In order to identify the causal agent of DON accumulation in soya, contamination of seed by Fusarium species was investigated. A total of 200 seeds were surface sterilized. One hundred were directly plated on selective Fusarium media. The other 100 seeds were first grinded and then distributed in Fusarium selective agar plates. A total of 20 Fusarium isolates were obtained. Morphological species determination was confirmed by EF-1á sequencing by sequence comparison using the Fusarium database. No known DON producing species was detected. Fusarium verticilliodes was the most recurrent species therefore presence of other Fusarium toxin can be expected. Further isolation attempts are in progress. doi:10.1016/j.toxlet.2010.03.1082
P309-049 Multiresidue analysis of pesticides in pollen by pressurized liquid extraction and gas chromatography mass spectrometry H. Berrada 1 , C. Juan 2 , G. Font 1 Universidad de Valencia, Spain, 2 Centro Superior de Investigaciones en Salud Pública, Spain
1
Pesticides are extensively used to protect food against pests and diseases. However, they can remain in food causing some adverse effects. Thus, it is important to analyze and monitor pesticides to investigate the relationship between exposure and health risks. The pollen is an important product consumed as a dietary supplement by humans due to its high contents of nutrients. Pollen can be also important source of pollutants and pesticides residues used widely in agriculture. A simple method for the simultaneous determination of 17 pesticides in pollen has been developed using pressurized liquid extraction (PLE) and gas chromatography–mass spectrometry (GC–MS). Pollen (5 g) was dispersed in extracting phase C (18), and this mixture was introduced into a stainless steel extraction cell which was positioned in the pressurized liquid extraction (PLE) system ASE 200. The pressurized liquid extraction operational parameters were optimized and no precipitating protein and removing fat steps were required. Pesticides were subsequently eluted and determined by gas chromatography with electron impact mass spectrometric detection in the selected ion monitoring mode (GC–MS-SIM) of three fragment ions to provide a high degree of sensitivity and specificity. Spiked blank pollen samples were used for matrix-matched calibration standard to eliminate the matrix effect observed in the chromatographic determination. Recovery studies were performed at 50, 100, and 250 g/kg fortification levels for each pesticide, and the recoveries obtained were >65% with relative standard deviations of <20%. Good resolution of the pesticide mixture was achieved in approximately 45 min. The detection limits of the method ranged from 5 to 15 g/kg for the different pesticides studied. The developed method is linear over the range assayed, 25–200 g/kg, with determination coefficients >0.996. The proposed method was applied to the analysis of pesticides in pollen samples collected at Valencia markets. doi:10.1016/j.toxlet.2010.03.1083
S343
P309-050 Development and validation of a liquid chromatography tandem mass spectrometry method for the analysis of macrolides in honey H. Berrada 1 , C. Juan 2 , C. Igualada 2 , G. Font 1 1
Universidad Valencia, Spain, 2 Centro Superior de Investigaciones en Salud Pública, Generalitat Valenciana, Valencia, Spain The macrolide residues in honey are a potential health risk for consumers because of allergic reactions. However, due to the lack of macrolide’s MRL in Europe for antibiotic residues in honey the limit of decision of the best available analytical method determine whether residue levels are considered tolerable or not, which somehow it implies the development of very sensitive analytical methods. Nonetheless, the Community Reference Laboratories (CRLs) have suggested a minimum required performance limit (MRPL) to improve the performance of analytical methods in residue control. For honey the CRLs has suggested MRPL for only two macrolides, tylosin and erythromycin are 20 g/kg. A reproducible, sensitive and selective analytical method was developed and validated by liquid chromatography tandem mass spectrometry (LC–MS/MS) for the analysis of six macrolides in honey: erythromycin, spiramycin (the sum of I, II, III), tylosin A, B, C, D (tylosin A, desmycosin, macrocin, relomycin, respectively), josamycin, tilmicosin, lincomycin and roxithromycin was used as internal standard. The method consisted on a basic extraction (pH:10) with trisodium phosphate 12-hidrate 0.1 M, followed by centrifugation and clean up step on SPE cartridge. The eluted residue was analyzed by LC–MS/MS using ESI source in positive ion mode. Method validation was achieved in honey according to the criteria laid down in the Commission Decision 2002/657/EC and decision limit (CCá) detection capabilities (CCâ), accuracy and precision (repeatability and within lab reproducibility) were calculated. CCá were below the MRPL suggested by CRLs, for all the studied macrolides in honey and a successful application for the analysis residue control of these macrolides in different honey samples was reached. doi:10.1016/j.toxlet.2010.03.1084
P309-051 Occurrence of ochratoxin A in foods commonly consumed in Turkey S. Ozden, A.S. Akdeniz, B. Alpertunga Istanbul University, Faculty of Pharmacy, Department of Pharmaceutical Toxicology, Istanbul, Turkey Ochratoxin A (OTA) is a mycotoxin produced by several species of Aspergillus and Penicillium species. OTA contaminates in a variety of food products, resulting in chronic human exposure. Tarhana, a traditional fermented and dried yoghurt cereal food, is an important component of the daily diet in Turkey. This study was undertaken to determine the presence of OTA in tarhana from Turkey. For this purpose, 83 samples of different types of tarhana were collected during 2008–2009 years. The samples were extracted using methanol in NaHCO3 (3%, w/v) (70:30, v/v) solution followed by immunoaffinity clean up. The determination was carried out by high-performance liquid chromatography equipped with fluorescence detector. The detection limit of OTA was 0.05 ng/g and OTA identity was confirmed by methyl ester formation. The whole procedure was simple and fast if compared with