[Show abstract][Hide abstract] ABSTRACT: A comprehensive strategy for the analysis of current airborne pesticides has been developed using liquid chromatography coupled to high resolution mass spectrometry. The methodology includes both quantitative target analysis and post-run target screening analysis. The quantitative method was validated after a previous statistical optimisation of the main factors governing the ion source ionization and a study of the single-stage Orbitrap fragmentation through the HCD cell. The quantitative method presented recoveries ranging from 73 to 116%, with precision (RSD) lower than 20%, for the 35 substances in the scope of the target method. The full-scan accurate mass data were acquired with a resolving power of 50000 FWHM (scan speed, 2Hz), and alternating two acquisition events, ESI+ without fragmentation and ESI+ with fragmentation. The method-LOQ was 6.5pgm(-3) for most of the target pesticides. For post-target screening a customized theoretical database, that included pesticides, metabolites and other substances such as emerging flame retardants was built up. For identification, accurate exact mass with less than 5ppm, and some diagnostic ions including isotopes and/or fragments were used. The strategy was applied to ten samples collected in a rural area of Valencia (Spain). Four pesticides, namely carbendazim, metalaxyl, myclobutanil and terbuthylazine, were detected in concentrations from 16pgm(-3) to 174pgm(-3). Some pesticides and metabolites (endothal, fenfuram, terbuthylazine-2-OH), in addition to two flame retardants were tentatively identified in the post-run target screening analysis.
Journal of Chromatography A 10/2014; · 4.61 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Volatile compounds released during the production of wine at different steps of the winemaking process were evaluated using semipermeable membranes based passive samplers. Preliminary data on the differences between five wine varieties were provided together with the indoor quality of air to which winery workers are exposed during their professional activity. A simple, green and fast analytical methodology was employed for the direct analysis of deployed samplers by using head space (HS) gas chromatography–mass spectrometry (GC–MS) without any sample pre-treatment and avoiding the use of solvents. Terpenes as styrene, pinene, p-cymene and limonene were found at concentration levels ranging from 3 to 577 ng m− 3 and benzene, toluene, ethylbenzene, and xylenes (BTEX) were also detected at concentration levels between 13 to 525 ng m− 3 for samplers deployed inside containers. Only BTEX below 52 ng m− 3 was detected in the working ambient air.
[Show abstract][Hide abstract] ABSTRACT: Toxic substances such as veterinary drugs, mycotoxins, plant toxins and ergot alkaloids are frequently present in animal feed due to their misuse or also because of the environment. The monitoring and analysis of the presence of these potentially hazardous chemicals remains one of the main tasks to ensure feed safety. Thus, the trend to guarantee quality and safety of feedstuff is going towards targeted screening approaches using high resolution mass spectrometry (HRMS). In this work, an ultra high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) methodology is proposed for the multi-class multi-residue quantitative screening of veterinary drugs and other contaminants such as undesirable substances regulated by the European Union in feed, using an Orbitrap Exactive™. A database including the elemental composition, the polarity of acquisition, retention time and expected adducts was built for the targeted analysis of around 70 substances. High mass accuracy minor than 5 ppm was set as one of the identification criteria. A "one step" sample clean-up procedure was developed based in the QuEChERS methodology allowing the extraction of a wide range of molecules. An efficient chromatography was achieved using ultra high performance liquid chromatography with Thermo Hypersil Gold 100x2.1 mm 1.9µm column with a run time of 15min. The suitability of full scan HRMS method for screening and confirmatory purposes was evaluated.
6th International Symposium on Recent Advances in Food Analysis; 11/2013
[Show abstract][Hide abstract] ABSTRACT: Pesticides in the inhalable fraction of particulate matter (PM10) should be well tracked in order to contribute information to future exposure assessment in individuals of the general public. A total of 40 current-used pesticides and metabolites were searched for in ambient air samples collected from January through December 2010. The samples were taken from one remote, one urban and three rural sites in Valencia Region (Spain) and analyzed using liquid chromatography coupled to mass spectrometry in tandem (LC-MS/MS). In the PM10 fraction 17 pesticides and metabolites were detected overall, two of them currently banned (carbofuran and omethoate, although the latter is a metabolite of the permitted pesticide dimethoate). The detected pesticides appeared at frequencies ranging from 1 to 75%, with omethoate, terbuthylazine and its metabolites, and carbendazim presenting the highest frequencies. The concentrations detected ranged from few pg m−3 to thousands of pg m−3, with omethoate having the highest average concentration (141.15 pg m−3) in the 5 sites overall. Each station showed its own specific pesticide profile, which is linked to the different types of crops around each site. In the rural stations pesticide levels were greater in spring and early summer, which correlates with their application in agricultural practices. These findings suggest that more efforts are required to implement an extensive air monitoring network in Europe for pesticide control and to develop regulations or recommendations regarding safer pesticide levels in ambient air.
[Show abstract][Hide abstract] ABSTRACT: A simple, fast and green direct analytical methodology has been developed to evaluate the concentration level of volatile organic compounds (VOCs) in indoor areas of vehicle repair shops using membrane devices as passive samplers. VOCs retained in the samplers were directly determined without any sample pre-treatment and avoiding the use of solvents by head space (HS) coupled to gas chromatography-mass spectrometry (GC-MS) in only 20 min. Benzene, toluene, tetrachloroethene, m,p-xylene and o-xylene were found at concentration levels from 0.1 to 11.2 mg m(-3).
[Show abstract][Hide abstract] ABSTRACT: In this work, an ultra high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) methodology is proposed for the multi-class multi-residue screening of banned and unauthorized veterinary drugs in bovine urine, using an Orbitrap Exactive™ analyzer working at a resolving power of 50,000 FWHM in full scan, both in positive and negative mode. The method currently covers 87 analytes belonging to different families such as steroid hormones, β-agonists, resorcylic acid lactones (RAL), stilbens, tranquillizers, nitroimidazoles, corticosteroids, NSAIDs, amphenicoles, thyreostatics and other substances such as dapsone. A database including the elemental composition, the polarity of acquisition, retention time and expected adducts was built for the targeted analysis, and a high mass accuracy (<5ppm) was set as one of the identification criteria. After comparing different sample preparation procedures, QuEChERS was selected as the most appropriate methodology. An efficient separation of analytes was achieved using ultra high performance liquid chromatography with a column packed with sub-2μm particles. The performance of the method has been evaluated in accordance with the EU guidelines for the validation of screening methods for the analysis of veterinary drugs residues. The screening target concentrations were established between 0.2μg/l and 20μg/l, demonstrating the usefulness of UHPLC-HRMS as an ideal tool for compliance monitoring in regulatory laboratories.
Journal of Chromatography A 08/2012; 1258:55-65. · 4.61 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Previous studies have demonstrated that the commercial feed of aquacultured fish contains trace amounts of toxic and essential metals which can accumulate in tissues and finally be ingested by consumers. Recently rising temperatures, associated to the global warming phenomenon, have been reported as a factor to be taken into consideration in ecotoxicology, since temperature-dependent alterations in bioavailability, toxicokinetics and biotransformation rates can be expected. Sparus aurata were kept at 22°C, 27°C and 30°C for 3 months in order to determine the temperature effect on metallothionein induction and metal bioaccumulation from a non-experimentally contaminated commercial feed. A significant temperature-dependent accumulation of cadmium (Cd), copper (Cu), mercury (Hg), zinc (Zn), lead (Pb) and iron (Fe) was found in liver, together with that of manganese (Mn), Fe and Zn in muscle. Hg presented the highest bioaccumulation factor, and essential metal homeostasis was disturbed in both tissues at warm temperatures. An enhancement of hepatic metallothionein induction was found in fish exposed to the highest temperature.
[Show abstract][Hide abstract] ABSTRACT: Passive samplers have been widely used for volatile organic compounds determination. Following the green chemistry tendency of the direct determination of adsorbed compounds in membrane-based devices through using head space direct chromatography analysis, this work has evaluated the use of Amberlite XAD-2, XAD-4, and XAD-16 adsorbents as a filling material for passive samplers. Direct analysis of the membranes by HS-GC-MS involves a solvent-free method avoiding any sample treatment. For exposed membranes, recoveries ranged from 10% to 203%, depending on the compound and adsorbent used. The limit of the detection values ranged from 1 to 140 ng per sampler. Acceptable precision and sensitivity levels were obtained for the XAD resins assayed.
Journal of analytical methods in chemistry. 01/2012; 2012:728143.
[Show abstract][Hide abstract] ABSTRACT: Better knowledge of the occurrence of pesticides in the inhalable fraction of particulate matter (PM10) could be very useful for future exposure assessment in individuals of the general public. The present work studies the spatial and temporal distribution of the occurrence of currently used pesticides (CUPs) in PM10. Ambient air samples were collected from January through December 2010 at one remote, one urban and three rural sites in Valencia Region (Spain) and analyzed for 42 CUPs using a gas chromatography coupled to mass spectrometry in tandem (GC–MS/MS) approach. Overall, 24 pesticides were detected in the PM10 fraction, four of them currently banned pesticides. Among those detected, concentrations of two particle-bound pesticides (permethrin and pyrimethanil) were, to our knowledge, reported for the first time in air in the literature. The detected pesticides appeared at frequencies ranging from <1 to 47%, with chlorpyrifos, bifenthrin and diazinon presenting the highest frequencies. The concentrations detected ranged from a few to several hundred pg m−3, with ethoprophos showing the highest average concentration (149.2 pg m−3). Each station shows its own specific pesticide profile, which is linked to the different types of crops around each site. Seasonal patterns were observed in the rural stations of Alzira and Sant Jordi, correlating pesticide detection with their application in agricultural practices, mostly in spring and early summer. These findings suggest that more efforts are required to implement an extensive air monitoring network in Europe for pesticide control and to develop regulations or recommendations regarding pesticide levels in ambient air.
[Show abstract][Hide abstract] ABSTRACT: A new passive sampler based on low-density polyethylene (LDPE) layflat tube filled with chrome shavings from tannery waste residues was evaluated to determine volatile organic compounds (VOCs) in indoor and outdoor areas. VOCs were directly determined by head space-gas chromatography-mass spectrometry (HS-GC-MS) without any pretreatment of the sampler and avoiding the use of solvents. Limit of detection values ranging from 20 to 75 ng sampler(-1) and good repeatability values were obtained for VOCs under study with relative standard deviation values from 2.8 to 9.6% except for carbon disulfide for which it was 22.5%. The effect of the amount of chrome shavings per sampler was studied and results were compared with those obtained using empty LDPE tubes, to demonstrate the capacity of chrome shavings to adsorb VOCs.
Journal of analytical methods in chemistry. 01/2012; 2012:897872.
[Show abstract][Hide abstract] ABSTRACT: A new methodology has been developed to determine volatile organic compounds (VOCs) and pesticides in ambient air using membrane based devices as passive samplers. Pesticides were determined by gas chromatography with mass spectrometry detection (GC-MS) after their microwave-assisted extraction (MAE) from the passive sampler and the required clean-up. On the other hand, VOCs were also caught with the same samplers and directly determined by head space (HS) coupled to GC-MS. The use of samplers filled with florisil and activated carbon allows us to catch with a simple device both, VOCs and pesticides, with a high vapor pressure. Results obtained in the deployment of samplers in different sites of a phytosanitary plant evidenced the presence of high quantities of chlorpyriphos at thousand ng m(3) and also metalaxyl, oxyfluorphen and lindane at ng m(3) together with carbon disulfide, 2,2,4-trimethylpentane, ethylbenzene and xylene.
[Show abstract][Hide abstract] ABSTRACT: A confirmatory and sensitive procedure has been developed for the determination of 40 currently used pesticides (CUPs) in airborne particulate matter (PM 10) at trace level. The proposed method includes extraction of PM 10-bound pesticides by microwave-assisted extraction (MAE) followed by a gel permeation chromatography (GPC) clean-up and determination by GC-MS/MS. The injection mode and the main parameters in MS/MS were optimized. The matrix effect was also evaluated. Recoveries ranged from 70 to 120% except for pyrimethanil and pirimicarb. The limit of quantification (LOQ) ranged from 1.32 to 39.47 pg m(-3), when air volumes of 760 m(3) were collected. The method was applied to 38 samples collected from a rural station belonging to the atmospheric monitoring network of the Regional Valencia Government (Spain) during April-June 2010. Eighteen out of 40 pesticides investigated were found in at least one sample (bifenthrin, chlorothalonil, chlorpyriphos-e, chlorpyriphos-m, clorpropham, diazinon, dicofol, diphenylamine, fipronil, fludioxonil, folpet, malathion, metalaxyl, penconazole, quinoxyfen, triadimefon, trifluralin, and vinclozoline), with concentrations ranging from 1.32 to 625.80 pg m(-3).
[Show abstract][Hide abstract] ABSTRACT: An analytical methodology based on the use of a polyethylene layflat tube filled with activated carbon and Florisil (ACFL-VERAM) was employed for the passive sampling of volatile organic compounds (VOCs) in the air of working areas of packing industries. VOCs amount in the ACFL-VERAM sampler was directly determined through head-space-gas chromatography-mass spectrometry (HS-GC-MS) allowing a direct determination in only 20 min without the need of any previous treatment. Uptake parameters, like sampling rate (R(S)) and sampler-air partition coefficient (K(SA)), were determined for every studied VOC from adsorption isotherm data. Additionally, experimental equations have been proposed to predict R(S) and K(SA) from the octanol-air partition coefficients reported in the literature. The proposed methodology reaches method detection levels from 0.007 to 0.2 mg m(-3) for the studied VOCs.
[Show abstract][Hide abstract] ABSTRACT: Semipermeable membrane devices (SPMDs) were evaluated as passive samplers for the determination of 26 volatile organic compounds (VOCs) in contaminated air of occupational environments. A direct methodology based on the use of head-space-gas chromatography-mass spectrometry (HS-GC-MS) was developed for VOCs determinations in SPMDs, without any sample pre-treatment and avoiding the use of solvents. A desorption temperature of 150 degrees C for 10 min was sufficient for a sensitive VOCs determination providing limits of detection in the range of 15 ng SPMD(-1) for 21 of 26 studied compounds. Linear and equilibrium uptake models were established for each VOC from compound isotherms. Highly volatile compounds were slightly absorbed and moderately volatile compounds were strongly absorbed by SPMDs. This study is the first precedent of the use of SPMDs for the simultaneous sampling of a wide number of VOCs. The use of SPMDs is a simple and low cost alternative to ordinary sampling devices such as Radiello diffusive samplers or badge-type solid-phase supports.
[Show abstract][Hide abstract] ABSTRACT: Ambient air samples were collected, from 2006 to 2008 at three rural and two urban sites in Centre Region (France) and analyzed for 56 currently used pesticides (CUPs), of which 41 were detected. The four CUPs most frequently detected were the herbicides trifluralin, acetochlor and pendimethalin and the fungicide chlorothalonil, which were found with frequencies ranging between 52 and 78%, and with average concentrations of 1.93, 1.32, 1.84 and 12.15 ng m−3, respectively. Among the detected pesticides, concentrations of eight fungicides (spiroxamine, fenpropimorph, cyprodinil, tolyfluanid, epoxiconazole, vinchlozolin, fluazinam, fludioxinil), two insecticides (propargite, ethoprophos), and one herbicide (oxyfluorfen) are, to our knowledge, reported for the first time in the literature.The majority of the CUPs showed a seasonal trend, with most of the detections and the highest concentrations occurring during the spring and early summer. The most important pesticides detected were related to arable crops and fruit orchards, the main cultures in this region, highlighting the fact that the main sources come from local applications. Minor differences were found in the profiles of pesticides within rural areas and between rural and urban areas.
[Show abstract][Hide abstract] ABSTRACT: A new procedure for the passive sampling in air of benzene, toluene, ethylbenzene and xylene isomers (BTEX) is proposed. A low-density polyethylene layflat tube filled with a mixture of solid phases provided a high versatility tool for the sampling of volatile compounds from air. Several solid phases were assayed in order to increase the BTEX absorption in the sampler and a mixture of florisil and activated carbon provided the best results. Direct head-space-gas chromatography-mass spectrometry (HS-GC-MS) measurement of the whole deployed sampler was employed for a fast determination of BTEX. Absorption isotherms were used to develop simple mathematical models for the estimation of BTEX time-weighted average concentrations in air. The proposed samplers were used to determine BTEX in indoor air environments and results were compared with those found using two reference methodologies: triolein-containing semipermeable membrane devices (SPMDs) and diffusive Radiello samplers. In short, the developed sampling system and analytical strategy provides a versatile, easy and rapid atmospheric monitor (VERAM).
Journal of Chromatography A 11/2009; 1216(48):8549-56. · 4.61 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A confirmatory and rapid procedure has been developed for the determination of 30 currently used pesticides (CUP) in fine airborne particulate matter (PM 2.5) at trace level. The proposed method includes extraction of PM 2.5-bound pesticides by microwave-assisted extraction (MAE) followed by a direct injection into LC-MS/MS. The main parameters affecting the MAE extraction (time, temperature and volume of solvent) were optimised using statistical design of experiments (DoE). The matrix effect was also evaluated. Recoveries ranged from 72 to 109% and the limit of quantification (LoQ) was 32.5 pg m(-3) for chlorpyrifos, 13.5 pg m(-3) for fenhexamid, imazalil and prochloraz, and 6.5 pg m(-3) for the rest of pesticides, when air volumes of 760 m(3) were collected. The method was applied to 54 samples collected from three stations of the atmospheric monitoring network of the Regional Valencia Government (Spain) during April-July 2009. Nineteen out of 30 pesticides investigated were found in at least one sample: omethoate, carbendazim, acetamiprid, thiabendazole, malathion, flusilazole, metalaxyl, azoxystrobin, iprovalicarb, myclobutanil, tebuconazole, triflumizole, cyprodinil, tebufenpyrad, buprofezin, pyriproxyfen, hexythiazox, flufenoxuron and fenazaquin. The measured concentrations ranged from 6.5 to 1208 pg m(-3). To our knowledge, 11 of the pesticides detected have been reported for the first time in ambient air.
Journal of Chromatography A 10/2009; 1216(51):8817-27. · 4.61 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Semipermeable membrane devices (SPMDs) have been used for the evaluation of the contamination of air in both the urban and the industrial area in Tangier (Morocco). Benzene, toluene, ethylbenzene and xylenes (BTEX), 12 polycyclic aromatic hydrocarbons (PAHs) and seven polychlorinated biphenyls (PCBs) were monitored with SPMDs, deployed in six different sites, and determined by using a microwave-assisted extraction with gel permeation chromatography (GPC) clean up for PAHs and PCBs determination; and a head-space direct measurement for BTEX. Gas chromatography with mass spectrometry detection was employed for the identification and quantification of the aforementioned pollutants. From the obtained results, it can be seen that the urban waste deposit and the industrial area of Moghogha present the highest concentrations of BTEX and PAHs, but significantly do not contribute to the contamination of air in the Tangier urban area. PCBs were not found in any of the sampled sites.
International Journal of Environmental Analytical Chemistry 07/2009; 89(Nos. 8–12):917-928. · 1.24 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: An automated, confirmatory and sensitive procedure has been developed and validated for the determination of Sudan (I-IV), Sudan Orange G, Sudan Red 7B and Para Red in hot chilli food samples. The proposed method includes pressurised liquid extraction (PLE) with acetone, gel permeation chromatography (GPC) clean-up and detection by liquid chromatography (LC) coupled to electrospray ionization in positive mode tandem mass spectrometry (ESI-MS-MS). The main parameters affecting the performance of the different ionization sources and PLE parameters were previously optimised using statistical design of experiments (DOE). The method was in-house validated on chilli powder and chilli meat. Linear calibrations were obtained with correlation coefficients R(2)>0.999. The limits of detection (LOD) and quantification (LOQ) of the method were in the ranges of 0.002-0.012 ng g(-1) and 0.006-0.036 ng g(-1), respectively for chilli powder. The decision limit and detection capability were between 0.005-0.022 ng g(-1) and 0.007-0.026 ng g(-1), respectively for chilli meat. Recoveries ranged from 94% to 105%. The applicability of the method to the determination of azo-dyes in hot chilli products was demonstrated.