Application of matrix solid phase dispersion to the determination of imidacloprid, carbaryl, aldicarb, and their main metabolites in honeybees by liquid chromatography–mass spectrometry detection

Abstract A method based on matrix solid phase dispersion (MSPD) using C18 as dispersant and dichloromethane–methanol as eluent and liquid chromatography–atmospheric pressure chemical ionization–mass spectrometry (LC–APCI–MS) has been developed for the simultaneous determination of imidacloprid, 6-chloronicotinic acid, carbaryl, aldicarb, aldicarb sulfoxide, and aldicarb sulfone in honeybees. The proposed method was compared with liquid–liquid extraction (LLE) combined with LC–APCI–MS analysis. Spiked blank samples were used as standards to counteract the matrix effect observed in the chromatographic determination. Recovery studies were performed at different fortification levels. Average re…

Occurrence of fumonisins B1 and B2 in broa, typical Portuguese maize bread

Fumonisin B1 (FB1) and fumonisin B2 (FB2) are mycotoxins mainly produced by Fusarium verticillioides, and Fusarium proliferatum, fungi species most commonly isolated from maize. The natural occurrence of FB1 and FB2 in broa, typical Portuguese maize bread, was evaluated in 30 samples. Twenty five were found positive with levels ranging from 142 to 550 [mu]g kg- 1. The limit established by the European regulations was exceeded by 27% of the samples. The tolerable daily intake for fumonisin B1, and B2, alone or in combination, for all of the analysed samples, was lower than 2 [mu]g kg- 1 body weight per day established by the European Commission. http://www.sciencedirect.com/science/article/B…

Surveillance of pesticide residues in fruits from Valencia during twenty months (2004/05)

Abstract The aim of this study was to investigate the pesticide residues in market fruits (oranges, tangerines, nectarines, peaches and khakis) from one Valencian Cooperative (Spain) and to conduct a monitoring of 32 organophosphorous, organonitrogen and organohalogenated pesticides and nine dithiocarbamate fungicides (DTCFs) usually applied on cultures of this area. Extracts were obtained by an official procedure for routine analysis based on ethyl acetate extraction. Residues of pesticides were determined by gas chromatography with nitrogen phosphorous detector (NPD), electron-capture detector (ECD) and mass spectrometry (MS) detectors. Mean recoveries obtained at fortification levels bet…

Occurrence of fumonisins B1, B2 and B3 in maize-products commercialized in Italy and Spain

Comparison of solid-phase microextraction and stir bar sorptive extraction for determining six organophosphorus insecticides in honey by liquid chromatography-mass spectrometry.

Abstract Two approaches based on sorptive extraction, solid-phase microextraction (SPME) and stir bar sorptive extraction (SBSE), in combination with liquid chromatography (LC)–atmospheric pressure chemical ionization mass spectrometry (MS) have been assayed for analyzing chlorpyriphos methyl, diazinon, fonofos, phenthoate, phosalone, and pirimiphos ethyl in honey. In both, SPME and SBSE, enrichment was performed using a poly(dimethylsiloxane) coating. Significant parameters affecting sorption process such as sample volume, sorption and desorption times, ionic strength, elution solvent, and dilution (water/honey) proportion were optimized and discussed. Performance of both methods has been …

Comparison of basal cytotoxicity of seven carbamates in CHO-K1 cells

The cytotoxic effects of seven carbamate pesticides, aldicarb, aldicarb sulfone, aldicarb sulfoxide, benfuracarb, pirimicarb, propoxur and thiobencarb, were compared in Chinese hamster ovary (CHO-K1) cell line of Circetulus griseus. The endpoints evaluated were lysosomal function by neutral red assay and mitochondrial integrity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT assay). The carbamates tested were evaluated in both serum-free medium and in serum-containing medium. Results demonstrate that CHO-K1 lysosomes appeared more susceptible to propoxur, aldicarb and its metabolites than mitochondria. Aldicarb was the most toxic carbamate pesticide tested on CHO-K1 cel…

Application of capillary electrophoresis-mass spectrometry for determining organic food contaminants and residues.

Food contamination continues to be a serious problem around the world. Surveillance of chemical contaminants in foods is important not only for public health but also because of the negative economic impact of contamination. From the analytical perspective, analysis of contaminants in food is an extremely challenging area. There is a wide variety of questions, ranging from the quantification of extremely low levels of individual components to the detailed assessment and evaluation of the analytical technique possibilities. This review considers the applications of CE coupled to MS detection (CE-MS) for the analysis of organic contaminants in food. Analytical information on sample concentrat…

G.P.16.04. Branching enzyme deficiency should be considered in the differential diagnosis of severe congenital hypotonia

Current trends in solid-phase-based extraction techniques for the determination of pesticides in food and environment

Solid-phase extraction (SPE) procedures for pesticide residues in food and environment are reviewed and discussed. The use of these procedures, which include several approaches such as: matrix solid-phase dispersion (MSPD), solid-phase micro-extraction (SPME) and stir-bar sorptive extraction (SBSE), represents an opportunity to reduce analysis time, solvent consumption, and overall cost. SPE techniques differ from solvent extraction depending on the interactions between a sorbent and the pesticide. This interaction may be specific for a particular pesticide, as in the interaction with an immunosorbent, or non-specific, as in the way a number of different pesticides are adsorbed on apolar or…

Effects of four carbamate compounds on antioxidant parameters

Abstract The effect of four carbamates, aldicarb and its metabolites (aldicarb sulfone and aldicarb sulfoxide) and propoxur on glutathione content and the activity of the enzymes involved in the sulfur-redox cycle in the mammalian cellular model CHO-K1 cells after 24-h exposure were determined. Carbamate exposure resulted in a depletion of intracellular reduced glutathione (GSH) content, no change was observed in oxidized glutathione (GSSG) and a decrease in GSH/GSSG ratio was detected. After carbamates exposition a GSH/GSSG decreases in ranged from 12.44% to 21.35% of control was observed. Depletion of GSH levels was accompanied by the induction of glutathione reductase (GR) after 24 h exp…

Radon and material radiopurity assessment for the NEXT double beta decay experiment

Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAM

Exposure assessment of fruits contaminated with pesticide residues from Valencia, 2001– 03

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 deviation20%. Limits of quantificat…

Toxicological Assessment of Recombinant Xylanase X22 in Wine

Toxicological evaluation of xylanase X(22) from Aspergillus nidulans expressed in a wine yeast strain was carried out. The safety of the X(22) intake was assessed by digestibility, bioinformatic, and mouse short-term repeated dosing studies, although X(22) shows resistance to proteolytic degradation in the gastrointestinal system, is a minority protein component (<0.5 10(-)(6) %) of the produced wine, and shows no significant amino acid sequence homology to any known food allergens. The 4-week oral toxicity study was performed in Swiss mice at a dose level of 0.01, 0.1, or 1 mg/kg/day (these dosages correlate to 8, 80, and 800 times, respectively, the enzyme amount contained in 250 mL of wi…

Simultaneous determination of imidacloprid, carbendazim, methiocarb and hexythiazox in peaches and nectarines by liquid chromatography–mass spectrometry

Abstract A liquid chromatographic (LC) atmospheric pressure chemical ionization mass spectrometric (MS) method is described for determining imidacloprid, carbendazim, methiocarb and hexythiazox in peaches and nectarines. The samples were extracted with ethyl acetate and anhydrous sodium sulfate. Recoveries yield for spiking samples were ranged from 64±9% (R.S.D) for carbendazim to 108±14% (R.S.D.) for hexythiazox at the concentration of 0.1 mg kg−1 (n=5). The correlation coefficients were greater than 0.998 over the range between 0.02 and 2 mg kg−1. The limits of quantitation (LOQ) were 0.02 mg kg−1 for all the pesticides. The applicability of the method to detect and quantify imidacloprid,…

Incidence, Diagnosis, and Outcome of Acquired Thrombotic Thrombocytopenic Purpura (aTTP): A Nationwide Survey By the Spanish Apheresis Group

Introduction: Acquired thrombotic thrombocytopenic purpura (aTTP) is a rare disease characterized by a severe deficiency of the enzymatic activity of ADAMTS13 caused by autoantibodies, with an incidence of 3-4 x106inhabitants per year according to the few published data available. Accurate estimates of the incidence of aTTP are important to assess the resources required for current treatments and to anticipate the need to develop new treatments. The aim of this study was to determine the actualincidence of aTTP in Spain, as well as its diagnosis, management, and associated complications. Material and methods:A cross-sectional surveywascarried out among hematologists working in Spanish hospi…

In vitro cytotoxicity of patulin, deoxynivalenol, nivalenol and zearalenone on CHO-K1 cells

Analytical Methods for Pesticide Residue Determination in Bee Products

Monitoring pesticide residues in honey, wax, and bees helps to assess the potential risk of these products to consumer health and gives information on the pesticide treatments that have been used on the field crops surrounding the hives. The present review seeks to discuss the basic principles and recent developments in pesticide analysis in bee products and their application in monitoring programs. Consideration is given to extraction, cleanup, chromatographic separation, and detection techniques.

Multi-mycotoxin analysis in North African semolina samples using a modified QuEChERS-based extraction procedure and HPLC–MS/MS

Cognitive impairment is related to oxidative stress and chemokine levels in first psychotic episodes.

Abstract Introduction This study measures the levels of various markers of oxidative stress and inflammation in blood samples from first-episode psychosis (FEP) patients, and examines the association between these peripheral biomarkers and cognitive performance at 6 months after treatment. Methods Twenty-eight FEP patients and 28 healthy controls (matched by age, sex and educational level) had blood samples taken at admission for assessment of total antioxidant status, superoxide dismutase (SOD), total glutathione (GSH), catalase (CAT), glutathione peroxidase, lipid peroxidation, nitrites and the chemokine monocyte chemoattractant protein-1 (MCP-1). A battery of cognitive tests was also app…

Comparison of gas and liquid chromatography coupled to mass spectrometry for the residue analysis of pesticides in organges

Liquid chromatography-mass spectrometry (LC-MS) with atmospheric pressure chemical ionization (APCI), and gas chromatography-mass spectrometry (GC-MS) with electron impact ionization (EI), are compared for the determination of eight pesticides in oranges. Seven of the selected pesticides, chlorpyriphos, chlorpyriphos-methyl, imazalil, α and β-endosulfan, endosulfan sulphate and dicofol, are commonly determined by GC whereas one, thiabendazole, can only be directly determined by LC. Primary ions [M-H]− or [M-Cl+O]− are obtained using LC-APCI-MS in negative ionization (NI) mode. In contrast, a high degree of fragmentation is reported with GC-MS. Both techniques were applied to oranges, which …

Dietary administration of high doses of pterostilbene and quercetin to mice is not toxic.

The aim of this study is to evaluate possible harmful effects of high doses of t-pterostilbene (t-PTER) and quercetin (QUER) in Swiss mice. Mice were fed during 28 days at doses of 0, 30, 300, and 3000 mg/kg body weight/day of t-PTER, QUER, or a mixture of both, t-PTER + QUER, which are equivalent to 5, 50, and 500 times, respectively, the estimated mean human intake of these polyphenols (25 mg/day). Daily oral administration of QUER, t-PTER, or a mixture of both of them did not cause mortality during the experimental period. There were no differences in food and water consumption on sex. No significant body weight gain in the male or female groups was observed. Red blood cell number and th…

Rapid screening of organophosphorus pesticides in honey and bees by liquid chromatography—Mass spectrometry

Twenty-two organophosphorus pesticide residues were simultaneously determined in honey and honeybee samples by extraction procedures based on solid-phase and liquid chromatography-atmospheric pressure chemical ionization-mass in positive and negative ionization modes. Pesticides in honeybee samples were extracted by matrix solid phase dispersion with C18 silica and subsequently eluted with a mixture of dichloromethane-methanol (85∶15, v/v). The average recoveries from spiked honeybees (0.5–10 μg g−1) ranged from 76% for coumaphos to 100% for omethoate, with relative standard deviations between 3 and 17%. Limits of detection were ≤0.13 μg g−1 and limits of quantification were ≤0.43 μg g−1. H…

In vitro effect of organophosphate pesticides, Malathion and chlorpyriphos, on lipid peroxidation and antioxidant enzymes

Effects of carbamates as oxidative stressors on glutathione levels and lipid peroxidation in CHO-K1 cells

Control of pesticide residues by liquid chromatography-mass spectrometry to ensure food safety.

Liquid chromatography-mass spectrometry (LC-MS) has become an invaluable technique for the control of pesticide residues to ensure food safety. After an introduction about the regulations that highlights its importance to meet the official requirements on analytical performance, the different mass spectrometers used in this field of research, as well as the LC-MS interfaces and the difficulties associated with quantitative LC-MS determination, are discussed. The ability to use practical data for quantifying pesticides together with the option of obtaining structural information to identify target and non-target parent compounds and metabolites are discussed. Special attention is paid to the…

Determination of carbamate residues in fruits and vegetables by matrix solid-phase dispersion and liquid chromatography-mass spectrometry.

Abstract Thirteen carbamates were analysed in orange, grape, onion and tomatoes by matrix solid-phase dispersion (MSPD) followed by liquid chromatography–mass spectrometry (LC–MS). Electrospray (ES) and atmospheric pressure chemical ionisation (APCI) were compared and both gave similar results in terms of sensitivity and structural information because at 20 V fragmentor voltages the fragmentation is minimal. The efficiency of different solid-phases (C18, C8, cyano, amine and phenyl) for the MSPD was compared. Mean recoveries using C8 varied from 64 to 106% with relative standard deviations of 5–15% in the concentration range of 0.01–10 mg kg−1. Matrix constituents did not interfere signific…

Simple liquid chromatography assay for analyzing ochratoxin a in bovine milk

Determination of organophosphorus pesticides in honeybees after solid-phase microextraction.

A method based on solid-phase microextraction (SPME) followed by gas chromatography with nitrogen-phosphorus detection was developed for the purpose of determining 18 organophosphorus pesticide residues in honeybee samples (Apis mellifera). The extraction capacities of polyacrylate and poly(dimethylsiloxane) fibers were compared. The main factors affecting the SPME process, such as the absorption time profile, salt, and temperature, were optimized. The method involved honeybee sample homogenization, elution with an acetone:water solution (1:1) and dilution in water prior to fiber extraction. Moreover, the matrix effect on the extraction was evaluated. In samples spiked at the 0.2 mg kg(-1) …

Comparative cytotoxicity effect of zearalenone and its metabolites on the CHO-K1 cells

1480P M2 macrophages could promote an immunosuppressive phenotype in a prospective cohort of advanced gastric cancer patients

Assessment of Pesticide Residues in Honey Samples from Portugal and Spain

Fifty samples of honey collected from local markets of Portugal and Spain during year 2002 were analyzed for 42 organochlorine, carbamate, and organophosphorus pesticide residues. An analytical procedure based on solid-phase extraction with octadecyl sorbent followed by gas chromatography-mass spectrometry (GC-MS), for organochlorines, and by liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS), for organophosphorus and carbamates, has been developed. Recoveries of spiked samples ranged from 73 to 98%, except for dimethoate (40%), with relative standard deviations from 3 to16% in terms of repeatability, and from 6 to 19% in terms of reproducibility. …

Analysis of organophosphorus pesticides in honeybee by liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry.

Pesticides applied in extended agricultural fields may be controlled by means of bioindicators, such as honeybees, in which are the pesticides bioaccumulate. Liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS) experiments with positive (PI) and negative (NI) ion modes were optimized for the analysis of 22 organophosphorus pesticides in honeybee samples. The extraction required 3 g of sample, which was extracted with acetone. The extract was purified with coagulating solution and reextracted with Cl(2)CH(2). Pesticides studied could be detected by both ionization modes except for parathion, parathion-methyl, and bromophos, which did not give signals …

Pesticide residues in oranges from Valencia (Spain)

One hundred and fifty citrus samples from an agricultural co-operative of the Valencian Community (Spain) were analysed for pre- and post-harvest pesticide residues using high performance liquid chromatography and gas chromatography. Among the residues from post-harvest treatments, imazalil was detected in 112 (74.7%) samples at a mean level of 1.2 mg/kg, thiabendazole in 21 (14.0%) samples at a mean level of 0.47 mg/kg and carbendazim in 5 (3.3%) samples at a mean level of 1.05 mg/kg. Among the residues from pre-harvest treatment, dicofol was detected in 28 (18.7%) samples at a mean level of .28 mg/kg chlorpyriphos in 19 (12.7% samples at a mean level of 0.16 mg/kg and endosulfan in 11 (7.…

Impacto de la enfermedad de Huntington en la familia

Se describen las alteraciones estructurales y emocionales de las familias con uno o más miembros enfermos de Huntington, en función de los diferentes síntomas, del afectado (descendientes, progenitores) y de las diferentes etapas. Consideramos que los servicios de ayuda a la familia deben estar compuestos por profesionales expertos en las necesidades específicas de esta enfermedad y que deben ayudar a planificar y diseñar las ayudas de manera individual, adecuada y flexible. Esta ayuda debe centrarse en superar el impacto de la enfermedad, en proporcionar información relevante, en buscar soluciones prácticas, en dar apoyo emocional, en diseñar los cuidados necesarios en cada caso y etapa, y…

Liquid chromatographic–mass spectrometric determination of post-harvest fungicides in citrus fruits

Liquid chromatography (LC)-atmospheric pressure ionisation (API)-mass spectrometry (MS) has been used to determine residues of five fungicides in oranges with a minimum sample cleanup. Atmospheric pressure chemical ionisation (APCI) and electrospray (ES) were compared and both gave similar results in terms of sensitivity and structural information. The main ions were [M+H]+ for carbendazim, imazalil, thiophanate methyl and thiabendazole, and [M+H-C4H9NHCO]+ for benomyl. Samples were extracted with sodium sulphate and ethyl acetate. Although benomyl and thiophanate methyl were transformed through the extraction procedure to carbendazim, the method showed good precision (13%) and recovery (70…