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1.
Food Chem Toxicol ; 121: 558-565, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30266314

ABSTRACT

A study on a set of ready-to-eat meals (n = 328) based on cereals, legumes, vegetables, fish and meat was carried out to determine the natural presence of twenty-seven mycotoxins by both liquid chromatography and gas chromatography coupled mass spectrometry in tandem (MS/MS) after QuEChERS extraction. The occurrence of mycotoxins was headed by cereal samples with 35% of samples contaminated by at least one mycotoxin followed by vegetables (32%), legumes (15%) and lastly, 9% of fish and meat samples were contaminated. DON was the most detected mycotoxin in vegetables, meat, fish and cereals with an incidence of 13% 18% 19% and 60%, respectively, and the highest mean levels were found in fish (1.19 µg/kg) and vegetable (1.53 µg/kg), respectively. The highest levels means were for HT-2 toxin ranging from 4.03 to 7.79 µg/kg, in cereal and legume samples respectively. In this last, HT-2 toxin was also the most prevalent (54%). In meat samples, OTA resulted with highest value with 8.09 µg/kg. Likewise, PCA analysis revealed a high correlation between the mycotoxins and the food groups analyzed. The findings indicate that there is no toxicological concern associated with exposure to mycotoxins for consumers as all levels were in accordance with the legislation.


Subject(s)
Food Contamination/analysis , Food Handling , Mycotoxins/chemistry , Animals , Cattle , Chickens , Edible Grain/chemistry , Fabaceae/chemistry , Fishes , Meat/analysis , Risk Assessment , Swine , Vegetables/chemistry
2.
Rev. toxicol ; 30(2): 198-202, jul.-dic. 2013. tab, ilus
Article in Spanish | IBECS | ID: ibc-126300

ABSTRACT

El deoxinivalenol (DON) es la micotoxina producida por hongos del género Fusarium que con más frecuencia se detecta en cereales y productos a base de cereales. Por ello, es recomendable realizar una continua monitorización de su incidencia en los alimentos. Este trabajo propone un procedimiento analítico basado en una extracción tipo QuEChERS seguido de una cromatografía de gases acoplada a un detector de triple cuadrupolo para la determinación de DON en rosquilletas. Se analizaron un total de 40 muestras las cuales se dividieron según su composición en dos grupos. El DON fue identificado en el 67,5% de las muestras analizadas con un contenido máximo de 61 μg/kg. A pesar de su incidencia elevada, los niveles de DON hallados fueron muy inferiores a los límites máximos legislados en la actual legislación europea (500 μg/kg). Los resultados obtenidos muestran una baja exposición a DON a través del consumo de esta matriz alimentaria (AU)


Deoxynivalenol (DON) is the most frequently detected mycotoxin in cereal and cereal-based products, and a continuous monitoring of this toxin in foodstuffs is highly desirable. In this sense, a QuEChERS based extraction and gas chromatography-tandem mass spectrometry detection is proposed to determine DON in an appetizer largely consumed, the wheat-based snacks. In this study, a total of 40 samples were analyzed. The samples were divided into two groups based on the composition. Extraction was carried out with acetonitrile followed by a dispersive solid phase extraction and analyzed for DON content by gas chromatography-tandem mass spectrometry (GC-QqQ-MS/MS) method. The overall occurrence of samples with DON was 67.5%, with maximum content of 61μg/kg. In spite of its high incidence, DON concentrations found in samples were much lower than the maximum limit established in the current European legislation (500 μg/kg) for the foodstuff evaluated. Data obtained indicated a low exposure to DON through the consumption of this food commodity (AU)


Subject(s)
Humans , Male , Female , Mycotoxins/analysis , Mycotoxins/toxicity , Food Supply , Edible Grain/chemistry , Edible Grain/toxicity , Food Analysis/methods , Fusarium/chemistry , Fusarium/pathogenicity , Food/toxicity , Data Analysis/methods , Data Analysis/statistics & numerical data
3.
Int J Food Microbiol ; 127(3): 284-9, 2008 Oct 31.
Article in English | MEDLINE | ID: mdl-18775579

ABSTRACT

Ochratoxigenic fungi are natural contaminants of cereal and the produced toxins are harmful to humans and animals. Ochratoxin A (OTA) is among the most important mycotoxins, and the International Agency for Research on Cancer (IARC) classifies it as possibly carcinogenic to humans (group 2B). A total of 61 samples of bread from the central zone of Portugal were analysed for OTA by liquid chromatography (LC) with fluorescence detection (FD). For confirmation two procedures were applied, methyl ester derivatization with boron trifluoride-methanol and liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI/MS/MS). As far as we know, this is the first report where on-line LC/electrospray ionization (ESI) tandem mass spectrometry (MS/MS) was used for OTA analysis in bread. Limits of detection (LOD) and quantification (LOQ) were 0.015 and 0.03 ng/g, using LC-FD, and 0.03 and 0.09 ng/g by LC-MS/MS. The incidence of OTA was 12.9% and 70.0% for wheat and maize bread, respectively. The highest OTA levels were obtained for maize bread, having one sample exceeded the European maximum limit established for OTA in cereal products. The estimate daily intake (EDI) was below the tolerable daily intake.


Subject(s)
Bread/analysis , Food Contamination/analysis , Ochratoxins/administration & dosage , Ochratoxins/analysis , Chromatography, Liquid , Consumer Product Safety , Food Microbiology , Humans , Incidence , Ochratoxins/isolation & purification , Portugal , Triticum/chemistry , Zea mays/chemistry
4.
Toxicon ; 51(7): 1281-7, 2008 Jun 01.
Article in English | MEDLINE | ID: mdl-18420246

ABSTRACT

The widespread contamination of foodstuffs and beverages by mycotoxins, such as ochratoxin A (OTA), has made the monitoring of human contamination levels essential. By using a sensitive, accurate and speedy method that combines extraction with 5% NaHCO(3), immunoaffinity column clean-up and HPLC with fluorescence detection, the human exposure to OTA through urine analysis can be monitored. This method is less invasive than blood monitoring and has the potential to be a good marker of human exposure. The limit of quantification of the method was 0.007 ng/mL of urine, with recoveries of OTA, from urine samples spiked at levels between 0.02 and 0.1 ng/mL, higher than 91% with RSD lower than 15.5%. This study evaluated OTA contamination levels in human urine sample fractions, collected in the morning and afternoon, in two populations, one from Coimbra city, in Portugal, and another from the Valencian community, in Spain. In the Coimbra population, 60 samples from 30 healthy individuals were analyzed, levels of OTA in 13 morning samples and 14 afternoon samples having been detected, with concentrations ranging from 0.011 to 0.208 and 0.008 to 0.11 ng/mL respectively. In the Valencia population, 62 samples from 31 healthy individuals were analyzed, with OTA being detected in 25 morning samples and 26 afternoon samples. The concentrations varied between 0.007 and 0.124 ng/mL in the morning samples, and 0.008 and 0.089 ng/mL in the afternoon samples. Significant differences were found between the morning levels of OTA from both populations (P=0.033). For afternoon samples, significant differences were not found, P value=0.163.


Subject(s)
Calcium Channel Blockers/urine , Environmental Monitoring/methods , Food Contamination/analysis , Ochratoxins/urine , Adolescent , Adult , Aged , Chromatography, High Pressure Liquid , Female , Humans , Male , Middle Aged , Portugal , Reproducibility of Results , Spain , Time Factors
5.
Food Addit Contam ; 24(11): 1268-74, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17852402

ABSTRACT

Patulin is a mycotoxin produced by species of Penicillium, Aspergillus and Byssochylamys. Several Scientific Committees classify patulin as mutagenic, embryotoxic and immunotoxic. It has been found as a natural contaminant of processed apple products and its presence may be indicative of the quality of fruit used in production. In this work, a method for the analysis of patulin is described, based on a simple liquid-liquid extraction with acetonitrile; patulin is analyzed using liquid chromatography with UV detection. Patulin identity was confirmed by GC-MS after its reaction with N-methyl-N-(trimethylsilyl)trifluoroacetamide. Fifty-three apple-containing products were analyzed and patulin was detected in 14 samples in a range 1.5-50.9 microg l(-1); six of which were above the maximum permitted level of the European Union. Based on these results and juice consumption by the Spanish adult population, patulin estimated intake was 0.42 ng kg(-1) body weight per day.


Subject(s)
Food Contamination/analysis , Fruit/chemistry , Malus/metabolism , Patulin/analysis , Beverages/analysis , Chromatography, Liquid/methods , Food Analysis/methods , Gas Chromatography-Mass Spectrometry/methods , Humans , Mutagens/administration & dosage , Mutagens/analysis , Patulin/administration & dosage , Spain , Spectrophotometry, Ultraviolet/methods
6.
Int J Food Microbiol ; 118(1): 87-91, 2007 Aug 15.
Article in English | MEDLINE | ID: mdl-17610975

ABSTRACT

Ochratoxin A (OTA) was extracted from 100 bread samples by using accelerated solvent extraction (ASE) and analyzed with liquid chromatography coupled with fluorescence detection. The presence of OTA was confirmed by methyl-ester derivatization. Bread samples were bought from different bakeries and supermarkets, 74 of non-organic and 26 of organic bread. The incidence of OTA varied between 20.3% and 23.0% for non-organic and organic bread, respectively. The highest values were obtained with non-organic versus organic products, five samples exceeded the European maximum permitted limit of OTA (3 ng/g) for this product. Estimated daily intake of OTA in this study was 1.6 ng/kg b.w./day. This value represents 32% and 10% of the tolerable daily intake (TDI) according to the Scientific Committee on Food of the European Commission and the FAO/WHO Committee of Experts on Food Additives, respectively. The daily intake estimated from this study reflects the necessity to take a vigilant attitude to guarantee food safety.


Subject(s)
Agriculture/methods , Bread/analysis , Food Contamination/analysis , Ochratoxins/administration & dosage , Ochratoxins/analysis , Chromatography, Liquid , Consumer Product Safety , Humans , Incidence , Ochratoxins/isolation & purification , Spain
7.
Rev Med Chir Soc Med Nat Iasi ; 111(1): 270-5, 2007.
Article in Romanian | MEDLINE | ID: mdl-17595880

ABSTRACT

UNLABELLED: This paper presents the results of a comparative study between the diets of the students from the University of Valencia and the diets of the students from the School of Pharmacy within Cluj-Napoca "I. Hatieganu" University of Medicine and Pharmacy. MATERIAL AND METHODS: The study focused on the analysis of Body Mass Index (BMI) of the students from the two universities, on the assessment of the calorie and nutrients intake per sexes, on the determination of the calorie and nutrient distribution per main courses and snacks, on the determination of the consumption per foodstuff groups at the main courses and snacks. All these parameters have been analysed and interpreted in a unitary form and according to the Spanish standards. RESULTS: No significant differences have been noticed between Spanish and Romanian students regarding the BMI. The food intake was adequate, but in case of Romanian students the timetable for meals is irregular and in the menu structure potatoes and bread are present in large amount. CONCLUSIONS: Additional nutritional education is required in order to eliminate the errors and miss-conception related with the food intake.


Subject(s)
Diet/statistics & numerical data , Feeding Behavior , Nutritional Status , Students/statistics & numerical data , Universities , Adult , Body Mass Index , Body Weight , Energy Intake , Female , Food/statistics & numerical data , Fruit , Health Education , Humans , Male , Nutrition Assessment , Romania , Spain , Vegetables
8.
Food Addit Contam ; 24(4): 381-90, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17454111

ABSTRACT

Fumonisin B(1) (FB(1)) and fumonisin B(2) (FB(2)) are mycotoxins mainly produced by Fusarium verticillioides and Fusarium proliferatum, which are field pathogens of maize. A survey was conducted on the incidences of FB(1) and FB(2) in both maize and derived products purchased in Portugal. The analytical method involved extraction with methanol-water, clean-up by immunoaffinity column and derivatization with naphthalene-2,3-dicarboxaldehyde. Determination was carried out by high-performance liquid chromatography (HPLC) with spectrofluorimetric detection, with liquid chromatography/mass spectrometry (LC/MS) confirmation. The presence of FB(1) and FB(2) was determined in 67 samples of maize and maize-based foods, such as flour, semolina, starch, sweet maize, cornflakes and other breakfast cereals, and snacks collected in 2005. FBs were found in 15 samples at concentrations ranging from 113 to 2026 microg kg(-1). Two of the samples showed higher contamination levels than the limits established by the European Commission Regulation. None of the samples contained levels of fumonisins that would lead to an exposure exceeding the tolerable daily intake (TDI).


Subject(s)
Carcinogens, Environmental/analysis , Fumonisins/analysis , Zea mays/chemistry , Chromatography, High Pressure Liquid/methods , Edible Grain/chemistry , Flour/analysis , Food Contamination/analysis , Fusarium/chemistry , Portugal , Starch/analysis
9.
Food Addit Contam ; 24(3): 285-91, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17364931

ABSTRACT

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.


Subject(s)
Food Contamination/analysis , Fruit/chemistry , Ochratoxins/analysis , Oryza/chemistry , Carcinogens/analysis , Chromatography, Liquid/methods , Food Analysis/methods , Humans , Morocco , Mycotoxins/analysis , Nuts/chemistry
10.
Int J Food Microbiol ; 115(1): 124-7, 2007 Apr 01.
Article in English | MEDLINE | ID: mdl-17218031

ABSTRACT

Fifty eight (58) samples of cereals for human consumption (20 corn flour, 17 wheat flour) and poultry feeds (n=21) purchased from popular markets of Rabat in Morocco were analyzed for aflatoxins (AF) by HPLC with immunoaffinity column (IAC) clean-up and fluorimetric detection. The incidence of AF in corn, wheat flour and poultry feeds was about 80, 17.6 and 66.6% respectively. High contamination levels were found in corn and poultry feeds samples. Levels of contamination of analyzed samples with AFB1 ranged from 0.23 to 11.2, 0.03 to 0.15 and 0.05 to 5.38 ng/g for corn, wheat and poultry feeds respectively. Results showed also that the contamination of 10% of samples of corn was higher than the limit set by EU regulations for AFB1 and total AF. This is the first report on the determination of AF in corn, wheat and poultry feeds from Morocco by HPLC and IAC.


Subject(s)
Aflatoxins/analysis , Animal Feed/analysis , Edible Grain/chemistry , Food Contamination/analysis , Animals , Chickens , Chromatography, High Pressure Liquid/methods , Incidence , Morocco/epidemiology , Poultry Diseases/chemically induced , Poultry Diseases/epidemiology , Poultry Diseases/pathology , Triticum/chemistry , Zea mays/chemistry
11.
Int J Food Microbiol ; 114(1): 25-9, 2007 Feb 28.
Article in English | MEDLINE | ID: mdl-17175055

ABSTRACT

Fifty four samples of pasteurized milk produced by five different dairies from Morocco were surveyed for the presence of aflatoxin M1 (AFM1) using immunoaffinity columns and liquid chromatography coupled to fluorescence detection. Confirmation of AFM1 identity in positive samples was based on the formation of AFM1 hemi-acetal derivative (AFM2a) after derivatization with trifluoracetic acid. Analytical results showed that 88.8% of the samples were contaminated with AFM1; 7.4% being above the maximum level of 0.05 microg/L set by the Moroccan and European regulations for AFM1 in liquid milk. The incidence of AFM1 in milk from these dairies was 100, 92.3, 90, 83.3 and 77.7% respectively, with AFM1 levels ranging from 0.001 to 0.117 microg/L and a mean value of 0.0186 microg/L. Based on the results presented in this study, the estimated daily intake of AFM1 was 3.26 ng/person/day. In this work, data on the natural occurrence of AFM1 in pasteurized milk produced in Morocco is presented for the first time.


Subject(s)
Aflatoxin M1/analysis , Chromatography, Liquid/methods , Food Contamination/analysis , Milk/chemistry , Poisons/analysis , Animals , Consumer Product Safety , Food Analysis , Food Handling/methods , Food Preservation/methods , Humans , Morocco
12.
Talanta ; 73(2): 246-50, 2007 Sep 15.
Article in English | MEDLINE | ID: mdl-19073023

ABSTRACT

Ochratoxin A (OTA) is a secondary fungal metabolite produced by several moulds, mainly by Aspergillus ochraceus, A. carbonarius, A. niger and by Penicillium verrucosum. The present work shows the results of comparative studies using different procedures for the analysis of OTA in maize bread samples. The studied analytical methods involved extraction with different volumes of PBS/methanol, different extraction apparatus, and clean-up through immunoaffinity columns. The separation and identification were carried out by high-performance liquid chromatography with fluorescence detection. The optimized method for analysis of OTA in maize bread involved extraction with PBS:methanol (50:50), and clean-up with IAC column. The limit of quantification was 0.033ngg(-1). Recoveries ranged from 87% to 102% for fortifications at 2.000 and 0.500ngg(-1), respectively, within-day R.S.D. of 1.4% and 4.7%. The proposed method was applied to 15 samples and the presence of OTA was found in nine samples at concentrations ranging from nd to 2.650ngg(-1).

13.
Crit Rev Food Sci Nutr ; 46(6): 473-8, 2006.
Article in English | MEDLINE | ID: mdl-16864140

ABSTRACT

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.


Subject(s)
Ochratoxins/analysis , Wine/analysis , Agriculture/methods , Aspergillus/growth & development , Aspergillus/metabolism , Climate , Fermentation , Food Contamination/analysis , Food Handling/methods , Fruit/growth & development , Ochratoxins/biosynthesis , Penicillium/growth & development , Penicillium/metabolism , Vitis/growth & development , Vitis/microbiology
14.
Food Addit Contam ; 23(7): 674-82, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16751144

ABSTRACT

A total of 634 samples of oranges, tangerines, peaches, nectarines, khakis and watermelons were collected from an Agricultural Valencia Community Cooperative during the May 2001 to April 2003 campaigns and they were analysed for 15 pesticides among those recommended for pest treatment. A conventional multiresidue analytical procedure based on ethyl acetate extraction was used followed by gas chromatography coupled to a nitrogen phosphorus detector for routine analysis; and mass spectrometry was performed for confirmation. Recovery studies with spiked samples at 0.5 mg kg-1 for each pesticide ranged from 52% for acephate to 87% for fenthion with a standard deviation <20%. Limits of quantification ranged from 0.1 to 100 microg kg-1. A total of 43% of samples contained pesticide residues; and 5% exceeded the maximum residue levels (MRLs). Nine of the pesticides studied were found. Malathion, which was the most frequently detected, was found in 121 samples (19%) at 0.002-4.25 mg kg-1; followed by fenthion in 104 samples (16%) at 0.005-2.3 mg kg-1; and methidation in 68 samples (10%) at 0.008-1.3 mg kg-1. Khaki showed the highest contamination rates with 60% of contaminated samples that exceeded more often the MRLs; and fenthion was the pesticide more frequently detected in all the commodities studied at levels above the European MRLs. The estimated daily intakes of each pesticide calculated from the results obtained were much lower than the acceptable daily intakes.


Subject(s)
Food Contamination/analysis , Fruit/chemistry , Pesticide Residues/analysis , Adult , Diet , Environmental Exposure/analysis , Food Analysis/methods , Humans , Maximum Allowable Concentration , Spain
15.
Int J Food Microbiol ; 107(2): 223-7, 2006 Mar 15.
Article in English | MEDLINE | ID: mdl-16316704

ABSTRACT

Ochratoxin A (OTA) was extracted from 84 rice samples and rice products by using accelerated solvent extraction (ASE) and analysed with liquid chromatography coupled with fluorescence detection. Samples were collected from rice cultivars, local markets and supermarkets; 64 were of non-organic and 20 of organic production. 7.8% of non-organic samples had OTA levels from 4.3 to 27.3 microg/kg and in 30% of organic samples was detected the presence of this mycotoxin varying from 1.0 to 7.1 microg/kg. OTA presence was confirmed by methyl-ester derivatization. Rice and rice products labelled with denomination of origin (DO) were not detected OTA due to the fact that its production has implemented food safety measures such as good agricultural practices (GAPs), good manufacturing practices (GMPs), and the hazard analysis and critical control point (HACCP) system. Estimated daily intake of OTA was 0.17 ng/kg b.w./day. This value reflects that the analysed samples have a minimal contribution to toxicological risk.


Subject(s)
Consumer Product Safety , Food Contamination/analysis , Ochratoxins/analysis , Oryza/chemistry , Chromatography, Liquid , Humans , Incidence , Ochratoxins/isolation & purification , Spain
17.
J Chromatogr A ; 1054(1-2): 397-401, 2004 Oct 29.
Article in English | MEDLINE | ID: mdl-15553168

ABSTRACT

Ochratoxin A (OTA) is a mycotoxin produced by fungi species belonging to the genera Aspergillus and Penicillium being isolated in alcoholic beverages. The aim of this work is developed and applied a procedure for the analysis of OTA in wines. An analytical method based on immunoaffinity column (IAC) for clean-up, liquid chromatography with fluorescence detection (LC-FD), and LC-FD after of OTA methylation was used to determine the occurrence of OTA in wines. Recoveries of this mycotoxin spiked to red wines at 0.5 ng/ml level were >90% with an average of relative standards deviations of 4%. Furthermore, 116 wine samples from designation of origin (DO) and three samples from food stores of Valencian Community (Spain) were examined for the occurrence of OTA being the levels of this mycotoxin ranged from <0.01 to 0.76 ng/ml. Finally, the estimated daily intake of OTA in this study was 0.15 ng/kg bw per day.


Subject(s)
Ochratoxins/analysis , Wine/analysis , Chromatography, Liquid , Sensitivity and Specificity , Spain , Spectrometry, Fluorescence
18.
Int J Food Microbiol ; 97(2): 221-5, 2004 Dec 15.
Article in English | MEDLINE | ID: mdl-15541809

ABSTRACT

A method is described for the determination of ochratoxin A (OTA) in soy sauce using phosphate-buffered saline (PBS) extraction, an immunoaffinity clean-up, a liquid chromatographic determination with fluorescence detection (LC-FD) and confirmation with LC-FD after methylation of OTA. Recoveries of OTA spiked to soy sauce samples at 0.25 ng/ml level were 90% with relative standard deviations of 4%. The limit of detection was 0.01 ng/ml for OTA using the proposed method. Furthermore, the proposed method was applied to 60 soy sauce samples from China and Japan and none of them were found to contain OTA.


Subject(s)
Food Contamination/analysis , Immunochemistry/methods , Ochratoxins/isolation & purification , Soy Foods/analysis , Chromatography, Liquid , Fluorescence , Quality Control , Sensitivity and Specificity
19.
J Chromatogr A ; 1050(2): 185-91, 2004 Oct 01.
Article in English | MEDLINE | ID: mdl-15508311

ABSTRACT

Washing with aqueous solutions of citric acid, ethanol, glycerol, hydrogen peroxide, potassium permanganate, sodium metabisulfite, sodium laurylsulfate (SLS), sodium hypochlorite, and urea is evaluated for pesticide residue reduction in nectarines and compared with simple tap water washing. Residues of pesticides commonly utilized in nectarines (chlorpyrifos, fenarimol, iprodione, malathion, methidathion, myclobutanil, parathion and pirimicarb) are extracted with ethyl acetate and anhydrous sodium sulfate, extract is concentred and analyzed by GC with nitrogen-phosphorus detection. The formation of possible toxic by-products (chlorpyrifos oxon, malaoxon, methidaoxon and paraoxon methyl) is studied by GC-MS. No toxic by-products are identified in the extracts of the washed samples for the washing-time and concentrations studied, but high levels of sodium hypochlorite, hydrogen peroxide and potassium permanganate form oxons from the organophosphorus pesticides. Ethanol, glycerol and SLS solutions removed near the 50% of the pesticide residues. The other solutions were not more effective than tap water washing. The amount of pesticide removed by washings is related to its water solubility and octanol-water partition coefficient.


Subject(s)
Fruit/chemistry , Pesticide Residues/analysis , Chromatography, Gas , Food Handling , Gas Chromatography-Mass Spectrometry , Indicators and Reagents , Reference Standards , Reproducibility of Results , Solubility , Solutions , Solvents
20.
J Chromatogr A ; 1046(1-2): 127-31, 2004 Aug 13.
Article in English | MEDLINE | ID: mdl-15387180

ABSTRACT

A new method based on extraction with octylsilica (C8) followed by liquid chromatography coupled with fluorescence detection (LC-FLD) was studied to determine ochratoxin A (OTA) from cereals and cereal products. Optimization of different parameters, such as type and amount of solid phase, type and volume of eluent and amount of sample were carried out. Recovery of OTA from rice samples spiked at 10 ng/g level was of 86% with relative standard deviation of 5%. The limits of detection and quantification of the proposed method were 0.25 and 0.75 ng/g, respectively. Furthermore, LC-FLD after of OTA methylation and liquid chromatography coupled to mass spectrometry with an electrospray interface were used for confirmation of OTA in all studied samples. The proposed method was applied to 62 samples of cereals and cereal products and the presence of OTA was found in seven samples.


Subject(s)
Chromatography, Liquid/methods , Edible Grain/chemistry , Ochratoxins/analysis , Sensitivity and Specificity , Spectrometry, Fluorescence
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