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Damia Barcelo - One of the best experts on this subject based on the ideXlab platform.

  • selective trace enrichment of chlorotriazine pesticides from natural waters and sediment samples using terbuthylazine molecularly imprinted polymers
    Analytical Chemistry, 2000
    Co-Authors: Francesca Lanza, Antal Tolokan, Viola Horvath, George Horvai, Börje Sellergren, Imma Ferrer, Damia Barcelo
    Abstract:

    Two molecularly imprinted polymers were synthesized using either dichloromethane or toluene as the porogen and terbuthylazine as the template and were used as solid-phase extraction cartridges for the enrichment of six chlorotriazines (Deisopropylatrazine, deethylatrazine, simazine, atrazine, propazine, and terbuthylazine) in natural water and sediment samples. The extracted samples were analyzed by liquid chromatography/diode array detection (LC/DAD). Several washing solvents, as well as different volumes, were tested for their ability to remove the matrix components nonspecifically adsorbed on the sorbents. This cleanup step was shown to be of prime importance to the successful extraction of the pesticides from the aqueous samples. The optimal analytical conditions were obtained when the MIP imprinted using dichloromethane was the sorbent, 2 mL of dichloromethane was used in the washing step, and the preconcentrated analytes were eluted with 8 mL of methanol. The recoveries were higher than 80% for all ...

  • monitoring of priority pesticides and other organic pollutants in river water from portugal by gas chromatography mass spectrometry and liquid chromatography atmospheric pressure chemical ionization mass spectrometry
    Journal of Chromatography A, 2000
    Co-Authors: Silvia Lacorte, Debora A Azevedo, Tereza Vinhas, Paula Viana, Damia Barcelo
    Abstract:

    Gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC-APCI-MS) were optimized and applied for the trace-level determination of 42 priority pesticides and 33 priority organic pollutants from European Union Directive EC 76/464. First, off-line solid-phase extraction of 200 ml of river water using an OASIS solid-phase extraction cartridge, followed by GC-MS was used. Next, selected samples that were positive to GC-MS were analyzed by LC-APCI-MS in order to detect further polar byproducts or to improve the determination of previously detected polar analytes. The transformation products of triazine pesticides like deethylatrazine (DEA) and Deisopropylatrazine (DIA) and compounds such as diuron and several chlorophenols were positively identified by LC-APCI-MS. The present methodology has also been used for searching for new analytes not included in the EC 76/464 list, like Irgarol, DEA and DIA. In addition it was applied to target pollutants in 43 river water samples from Portugal during a pilot survey from April to July 1999. Atrazine followed by simazine and 2,4,6-trichlorophenol were the most ubiquitous compounds detected in this area. The levels detected of the different compounds were in the range of: 0.01-2.73 microg/l, 0.05-0.74 microg/l, 0.02-1.65 microg/l, 0.02-5.43 microg/l, 0.01-0.40 microg/l, 0.01-0.26 microg/l, 0.02-0.61 microg/l, 0.01-3.90 microg/l, 0.01-1.24 microg/l, 0.02-2.3 microg/l, 0.01-0.13 microg/l and 0.01-0.5 microg/l for atrazine, simazine, terbuthylazine, alachlor, metolachlor, Irgarol, propanil; tributhylphosphate, diuron, 2,4,6-trichlorophenol, Deisopropylatrazine and deethylatrazine, respectively.

  • determination of atrazine and alachlor in natural waters by a rapid magnetic particle based elisa influence of common cross reactants deethylatrazine Deisopropylatrazine simazine and metolachlor
    Analytica Chimica Acta, 1995
    Co-Authors: J Gascon, E Martinez, Damia Barcelo
    Abstract:

    Abstract The determination of atrazine and alachlor in various water types (distilled, ground and estuarine waters) in the presence of the common interfering compounds deethylatrazine, Deisopropylatrazine and simazine (atrazine) and metolachlor (alachlor) has been investigated using direct rapid-magnetic particle-based ELISA. The interferences were studied at a fixed concentration of 0.5 μg l−1 atrazine or alachlor and at varying concentrations of the cross-reactants from 0.05 to 5 μg 1−1. Cross-reactivity values varied from 65–81% to 1.1% for deethylatrazine and metolachlor, respectively. Recommendations about the applications of the ELISA test to different types of water samples are given.

  • analysis of chlorotriazines and their degradation products in environmental samples by selecting various operating modes in thermospray hplc ms ms
    Journal of Agricultural and Food Chemistry, 1993
    Co-Authors: Joaquin Abian, G Durand, Damia Barcelo
    Abstract:

    Positive ion (PI) and negative ion (NI) modes in thermospray HPLC/MS as well as the daughter ion and neutral loss modes in thermospray HPLC/MS/MS were applied for the characterization of atrazine, simazine, cyanazine, deethylatrazine, Deisopropylatrazine, hydroxyatrazine, and chlorodiamino-s-triazine. PI mode gave always the [M+H] + ion as base peak. Filament-on NI mode, which was 2-3 orders of magnitude less sensitive, gave [M+2H] .− ions except for cyanazine and hydroxyatrazine, which showed the [M-H] − ion. In the filament-off NI mode only cyanazine and hydroxyatrazine could be detected, both giving the [M-H] − signal (.)

  • use of extraction disks for trace enrichment of various pesticides from river water and simulated seawater samples followed by liquid chromatography rapid scanning uv visible and thermospray mass spectrometry detection
    Environmental Science & Technology, 1993
    Co-Authors: Damia Barcelo, G Durand, Veronique Bouvot, Michel Nielen
    Abstract:

    C18 Empore extraction disks were used for the isolation and trace enrichment of several pesticides [chlorotriazines (atrazine, simazine, and cyanazine), the atrazine metabolites (deethyl- and Deisopropylatrazine), organophosphorus (parathion-ethyl, fenitrothion, fenamiphos, and tetrachlorvinphos), phenylurea (linuron), propioanilide (propanil), and carbamate (carbaryl)] from river water and simulated seawater, at concentration levels of 0.25, 25, and 1000 μg/L.

Jorge C. Masini - One of the best experts on this subject based on the ideXlab platform.

  • Online Sequential-Injection Chromatography with Stepwise Gradient Elution: A Tool for Studying the Simultaneous Adsorption of Herbicides on Soil and Soil Components
    2013
    Co-Authors: Ricardo De Prá Urio, Carlos M.c. Infante, Jorge C. Masini
    Abstract:

    The adsorption of triazine herbicides simazine (SIM), atrazine (ATR), and propazine (PRO) as well as the metabolites Deisopropylatrazine (DIA), deethylatrazine (DEA), and 2-hydroxyatrazine (HAT) on soil, humic acid, and soil modified with humic acidic was studied by sequential-injection chromatography with UV detection at 223 nm. An online monitoring system was assembled, which was composed of a tangential filter and a peristaltic pump for the circulation of the soil (25 g L–1) or humic acid (2.5 g L–1) suspensions. A stepwise gradient elution separated the compounds using three mobile phases whose compositions were 28, 40, and 50% (v v–1) methanol in 1.25 mmol L–1 ammonium acetate buffer, pH 4.7. The sampling throughput was about six analyses per hour; the linear dynamic range was between 100 and 1000 μg L–1 for all of the studied compounds. The detection limits varied from 9 μg L–1 for ATR to 36 μg L–1 for DEA. At contact times

  • montmorillonite as an adsorbent for extraction and concentration of atrazine propazine deethylatrazine Deisopropylatrazine and hydroxyatrazine
    Analytica Chimica Acta, 2006
    Co-Authors: Lilian Zarpon, Gilberto Abate, Luciana Dos B O Santos, Jorge C. Masini
    Abstract:

    Abstract Adsorption properties of the clay mineral montmorillonite in the potassium homoionic form (KMT) was investigated to achieve the extraction and concentration of the herbicides atrazine (AT) and propazine (PROP), as well as the main degradation products of atrazine, namely deethylatrazine (DEA), Deisopropylatrazine (DIA) and hydroxyatrazine (ATOH). A batch approach was proposed, with recovery percentages for AT, PROP and DIA higher than 90% at concentrations of 0.50 and 2.50 μg L −1 . For DEA and ATOH, however, low recoveries were obtained. For DEA, this fact can be explained by its low K d with KMT, contrary to ATOH, which interacts strongly with the mineral surface, hindering the complete desorption and hence, generating low recovery percentages. The influence of pH, ionic strength and humic acid was studied, and a comparison with the C 18 phase as SPE cartridges was carried out. Montmorillonite showed a similar performance to commercial cartridge for concentrations of AT, DEA and PROP, but better recoveries for DIA was obtained using the clay mineral. For ATOH the recovery was also higher on the clay mineral, although for this compound the most suitable SPE cartridge is constituted by cation exchange resin. After the concentration and elution steps, the 0.50 and 2.50 μg L −1 gave chromatographic peak areas that could be easily quantified with an analytical curve obtained in the concentration range between 7.5 and 100 μg L −1 . The obtained concentration factors are suitable to allow the application of the method to the monitoring of triazine residues in drinking water.

  • sorption of atrazine propazine deethylatrazine Deisopropylatrazine and hydroxyatrazine onto organovermiculite
    Journal of the Brazilian Chemical Society, 2005
    Co-Authors: Gilberto Abate, Jorge C. Masini
    Abstract:

    The interaction of atrazine (AT), propazine (PROP), deethylatrazine (DEA), Deisopropylatrazine (DIA) and hydroxyatrazine (HAT) was studied with the clay mineral vermiculite saturated with K+ (VTK), and with the mineral modified by insertion of hexadecyltrimethyl-ammonium (HDTMA-VT) in the interlayer of VTK. The crude VTK exhibited negligible interaction with AT, PROP and DEA, moderate interaction with DIA and strong interaction with HAT. For the HDTMA-VT materials, removal percentages from aqueous medium for initial concentrations between 0.05 and 1.00 mg L-1 were 56 to 63% for AT, 43 to 45% for DEA, 12 to 19% for HAT and 77 to 78% for PROP. Sorption of AT, DEA and PROP onto HDTMA-VT was significantly enhanced in comparison to VTK. Ionic strength and pH had no significant influence on the sorption process. Desorption of all compounds from HDTMA-VT after 24 h of contact time was between 20 and 30% of the amount initially adsorbed.

  • adsorption of atrazine hydroxyatrazine deethylatrazine and Deisopropylatrazine onto fe iii polyhydroxy cations intercalated vermiculite and montmorillonite
    Journal of Agricultural and Food Chemistry, 2005
    Co-Authors: Gilberto Abate, Jorge C. Masini
    Abstract:

    This paper describes the modification of the clay minerals vermiculite (VT) and montmorillonite (MT) by intercalating Fe(III) polymers of different [OH(-)]:[Fe(III)] ratios with the aim of removing atrazine (AT) and its metabolites deethylatrazine (DEA), Deisopropylatrazine (DIA), and hydroxyatrazine (ATOH) from aqueous solution. An enhancement of adsorption capacity was observed for both intercalated clay minerals in comparison to the potassium-saturated materials (KVT or KMT). The results showed that different [OH(-)]:[Fe(III)] molar ratios had a small influence on the adsorption capacity, as well as in the basal spacing, BET surface area, and porosity. For the lowest initial concentrations of AT, DIA, and ATOH (0.050 mg L(-)(1)) studied, the modified VT adsorbed almost 80% of AT and DIA, while ATOH was removed at concentration levels below the detection limit of the technique, implying in at least 99.5% of sorption. Weak interaction between intercalated VT and DEA was observed, although a significant adsorption enhancement occurred in comparison to KVT. Within a 24 h interval, desorption of AT and DIA in aqueous medium reached levels close to 20% of the amount initially adsorbed, while for ATOH only 3% of the adsorbed compound was desorbed. The adsorption capacity of the Fe(III)-intercalated VT decreased after the first adsorption/desorption cycle, implying that the material is not suitable for reutilization. The intercalated MT was a powerful sorbent for AT, DEA, DIA, and ATOH, removing all of these chemicals from solution almost quantitatively (sorption greater than 99.5%), even at initial concentrations as high as 1.0 mg L(-)(1). Additionally, desorption of AT, ATOH, and DIA in water was not measurable up to the tube corresponding to the initial concentration of 1.0 mg L(-)(1), suggesting strong irreversible binding of these compounds to the intercalated MT materials. Desorption of DEA from the intercalated MT was between 5 and 30%. Unlike what was observed for VT, the intercalated MT materials were recyclable, keeping an excellent performance when reutilized.

  • influence of humic acid on adsorption and desorption of atrazine hydroxyatrazine deethylatrazine and Deisopropylatrazine onto a clay rich soil sample
    Journal of Agricultural and Food Chemistry, 2004
    Co-Authors: Gilberto Abate, Jose Carlos P Penteado, Jonas D Cuzzi, Godofredo Cesar Vitti, Jaim Lichtig, Jorge C. Masini
    Abstract:

    Adsorption and desorption properties of atrazine and some of its metabolites, hydroxyatrazine (AT-OH), deethylatrazine (DEA), and Deisopropylatrazine (DIA), were studied with a clay-rich soil sample (clay content of 53%). A part of this soil was treated with humic acid (Soil-HA) to assess the influence of this important component of natural organic matter on adsorption and desorption processes. This study was performed using the batch approach with 1.0 g of soil, or Soil-HA, in 5.0 mL of 0.010 mol L-1 CaCl2 solution containing the herbicide and the metabolites in a concentration range between 0.010 and 5.0 mg L-1. After 24 h of contact time, the suspensions were centrifuged and the four compounds were quantified in the supernatant phases by high-performance liquid chromatography. The adsorption and desorption data of both Soil and Soil-HA were properly fitted by the linearized Freundlich equation. For the untreated soil, the adsorption affinity order evaluated as a function of the Kf values was AT-OH > AT...

M Fernandezperez - One of the best experts on this subject based on the ideXlab platform.

  • removal of atrazine and Deisopropylatrazine from water by montmorillonite phosphate crosslinked compounds
    Journal of Environmental Quality, 2000
    Co-Authors: E Gonzalezpradas, M Villafrancasanchez, F Del Reybueno, M D Urenaamate, M Fernandezperez
    Abstract:

    To assess the potential use of two montmorillonite-(cerium [Ce] or zirconium [Zr]) phosphate crosslinked compounds in removing organic pollutants from water, the adsorption of atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine) and one of the major metabolites of atrazine in water, Deisopropylatrazine (6-chloro-N4-ethyl-1,3,5-triazine-2,4-diamine), has been studied at 25 degrees C using batch experiments. The influence of the presence of 0.01 M KCl in the medium was also investigated for a better understanding of variables affecting the adsorption of these organic compounds. Experimental data points have been fitted to the Langmuir equation, with the results indicating a higher adsorption for Deisopropylatrazine than for atrazine on both adsorbents in saline and nonsaline medium. Variation of the uptake of atrazine and the metabolite in the solution of 0.01 M KCl shows an enhanced adsorption of Deisopropylatrazine on both samples compared with that of atrazine. Fourier-transformed infrared (FTIR) spectroscopic studies reveal that at the pH generated by the adsorbents (3.7 and 3.9 for Ce and Zr-montmorillonite compounds, respectively), atrazine and its metabolite interact with the surface of the adsorbents. X-ray diffraction analysis showed that the compounds studied are intercalated into the adsorbents. For the compounds considered, the cerium-montmorillonite adsorbent shows a higher capacity of adsorption compared with zirconium-montmorillonite adsorbent, so it might be particularly useful in removing atrazine and, to a greater extent, Deisopropylatrazine from water.

  • removal of diquat and Deisopropylatrazine from water by montmorillonite ce or zr phosphate crosslinked compounds
    Chemosphere, 1999
    Co-Authors: E Gonzalezpradas, M Villafrancasanchez, F Del Reybueno, M D Urenaamate, M Sociasviciana, M Fernandezperez
    Abstract:

    Abstract The adsorption of diquat (1,1′-ethylene-2,2′-dipyridilium dibromide) and one intermediate compound of the degradation of atrazine in water, Deisopropylatrazine, on two montmorillonite-(Ce or Zr) phosphate crosslinked compounds from aqueous solution under conditions of varied temperature (288 K and 308 K) has been studied. The experimental adsorption isotherms obtained for diquat on both adsorbents may be classified as H-type of the Giles classification which suggests that diquat molecules are strongly adsorbed on the samples. For the Deisopropylatrazine, L-type isotherms were obtained for both montmorillonite-(Ce or Zr) phosphate compounds, which suggests a moderate affinity of this metabolite by the active sites of the adsorbents. The increase of temperature from 288 K to 308 K does not clearly affect the adsorption process of diquat on both adsorbents whereas the Deisopropylatrazine adsorption decreases slightly as temperature increases possibly due to a mainly physical process. Fourier transform infrared (FTIR) spectroscopic studies reveal that at the pH generated by the adsorbents, the cationic herbicide interacts to a greater extent with the negative charged surface of the adsorbents than Deisopropylatrazine. For both model compounds, the ceriummontmorillonite adsorbent shows the higher capacity of adsorption compared with zirconiummontmorillonite adsorbent.

Gilberto Abate - One of the best experts on this subject based on the ideXlab platform.

  • behavior of atrazine and its degradation products deethylatrazine and Deisopropylatrazine in oxisol samples
    Water Air and Soil Pollution, 2016
    Co-Authors: Maristela F Amadori, Caio C Reboucas, Patricio Peraltazamora, M Grassi, Marcio B Rodrigues, Gilberto Abate
    Abstract:

    This work investigates the behavior of atrazine (AT) and its degradation products deethylatrazine (DEA) and Deisopropylatrazine (DIA) in oxisol samples. The study was carried out at different depths of maize culture soil under no-till management for up to 180 days. Additionally, controlled laboratory experiments were performed in open flasks in the absence of sunlight or in closed flasks at 4 °C. Higher AT dissipation occurred in the in the field as compared with the samples evaluated under controlled conditions, which indicated that environmental conditions might degrade AT. Interestingly, DEA and DIA levels were low, which suggested that leaching and runoff processes, formation of other degradation products, or even AT mineralization took place. Residual AT, DEA, and DIA were detected in the oxisol samples after 180 days depending on the initial amount of AT in the soil. This study has shown that straw plays a relevant role in AT retention and significantly contributes to DEA and DIA formation. At 180 days, straw samples contained AT concentrations near 100 μg kg−1 and concentrations of the more leachable DEA and DIA close to 50 μg kg−1 even under the influence of sunlight and rainfall. A preliminary analysis of natural water samples near the investigated region showed that DEA and DIA were absent and that AT concentrations were high, which pointed to the need for more detailed evaluation.

  • extraction method for the determination of atrazine deethylatrazine and Deisopropylatrazine in agricultural soil using factorial design
    Journal of the Brazilian Chemical Society, 2013
    Co-Authors: Maristela F Amadori, Gilcelia A Cordeiro, Caio C Reboucas, Patricio Peraltazamora, M Grassi, Gilberto Abate
    Abstract:

    An optimization procedure for the extraction of the herbicide atrazine (AT), and the main degradation products deethylatrazine (DEA) and Deisopropylatrazine (DIA) from an oxisol soil sample was carried out, for a soil from the Southwest of Parana State in Brazil, where AT is among the most largely employed herbicide. A comparison between shaking and ultrasound extraction was performed, to define a simple and fast extraction procedure, followed by the quantification using high performance liquid chromatography. It is important to inform that a factorial planning was employed, that was very important to define the best conditions of extraction by shaking. Appropriate recovery values were observed using soil samples from three different depths, as well as the relative standard deviation, suggesting the possibility to employ the proposed extraction method for quantification of AT, DEA and DIA in oxisol samples.

  • montmorillonite as an adsorbent for extraction and concentration of atrazine propazine deethylatrazine Deisopropylatrazine and hydroxyatrazine
    Analytica Chimica Acta, 2006
    Co-Authors: Lilian Zarpon, Gilberto Abate, Luciana Dos B O Santos, Jorge C. Masini
    Abstract:

    Abstract Adsorption properties of the clay mineral montmorillonite in the potassium homoionic form (KMT) was investigated to achieve the extraction and concentration of the herbicides atrazine (AT) and propazine (PROP), as well as the main degradation products of atrazine, namely deethylatrazine (DEA), Deisopropylatrazine (DIA) and hydroxyatrazine (ATOH). A batch approach was proposed, with recovery percentages for AT, PROP and DIA higher than 90% at concentrations of 0.50 and 2.50 μg L −1 . For DEA and ATOH, however, low recoveries were obtained. For DEA, this fact can be explained by its low K d with KMT, contrary to ATOH, which interacts strongly with the mineral surface, hindering the complete desorption and hence, generating low recovery percentages. The influence of pH, ionic strength and humic acid was studied, and a comparison with the C 18 phase as SPE cartridges was carried out. Montmorillonite showed a similar performance to commercial cartridge for concentrations of AT, DEA and PROP, but better recoveries for DIA was obtained using the clay mineral. For ATOH the recovery was also higher on the clay mineral, although for this compound the most suitable SPE cartridge is constituted by cation exchange resin. After the concentration and elution steps, the 0.50 and 2.50 μg L −1 gave chromatographic peak areas that could be easily quantified with an analytical curve obtained in the concentration range between 7.5 and 100 μg L −1 . The obtained concentration factors are suitable to allow the application of the method to the monitoring of triazine residues in drinking water.

  • sorption of atrazine propazine deethylatrazine Deisopropylatrazine and hydroxyatrazine onto organovermiculite
    Journal of the Brazilian Chemical Society, 2005
    Co-Authors: Gilberto Abate, Jorge C. Masini
    Abstract:

    The interaction of atrazine (AT), propazine (PROP), deethylatrazine (DEA), Deisopropylatrazine (DIA) and hydroxyatrazine (HAT) was studied with the clay mineral vermiculite saturated with K+ (VTK), and with the mineral modified by insertion of hexadecyltrimethyl-ammonium (HDTMA-VT) in the interlayer of VTK. The crude VTK exhibited negligible interaction with AT, PROP and DEA, moderate interaction with DIA and strong interaction with HAT. For the HDTMA-VT materials, removal percentages from aqueous medium for initial concentrations between 0.05 and 1.00 mg L-1 were 56 to 63% for AT, 43 to 45% for DEA, 12 to 19% for HAT and 77 to 78% for PROP. Sorption of AT, DEA and PROP onto HDTMA-VT was significantly enhanced in comparison to VTK. Ionic strength and pH had no significant influence on the sorption process. Desorption of all compounds from HDTMA-VT after 24 h of contact time was between 20 and 30% of the amount initially adsorbed.

  • adsorption of atrazine hydroxyatrazine deethylatrazine and Deisopropylatrazine onto fe iii polyhydroxy cations intercalated vermiculite and montmorillonite
    Journal of Agricultural and Food Chemistry, 2005
    Co-Authors: Gilberto Abate, Jorge C. Masini
    Abstract:

    This paper describes the modification of the clay minerals vermiculite (VT) and montmorillonite (MT) by intercalating Fe(III) polymers of different [OH(-)]:[Fe(III)] ratios with the aim of removing atrazine (AT) and its metabolites deethylatrazine (DEA), Deisopropylatrazine (DIA), and hydroxyatrazine (ATOH) from aqueous solution. An enhancement of adsorption capacity was observed for both intercalated clay minerals in comparison to the potassium-saturated materials (KVT or KMT). The results showed that different [OH(-)]:[Fe(III)] molar ratios had a small influence on the adsorption capacity, as well as in the basal spacing, BET surface area, and porosity. For the lowest initial concentrations of AT, DIA, and ATOH (0.050 mg L(-)(1)) studied, the modified VT adsorbed almost 80% of AT and DIA, while ATOH was removed at concentration levels below the detection limit of the technique, implying in at least 99.5% of sorption. Weak interaction between intercalated VT and DEA was observed, although a significant adsorption enhancement occurred in comparison to KVT. Within a 24 h interval, desorption of AT and DIA in aqueous medium reached levels close to 20% of the amount initially adsorbed, while for ATOH only 3% of the adsorbed compound was desorbed. The adsorption capacity of the Fe(III)-intercalated VT decreased after the first adsorption/desorption cycle, implying that the material is not suitable for reutilization. The intercalated MT was a powerful sorbent for AT, DEA, DIA, and ATOH, removing all of these chemicals from solution almost quantitatively (sorption greater than 99.5%), even at initial concentrations as high as 1.0 mg L(-)(1). Additionally, desorption of AT, ATOH, and DIA in water was not measurable up to the tube corresponding to the initial concentration of 1.0 mg L(-)(1), suggesting strong irreversible binding of these compounds to the intercalated MT materials. Desorption of DEA from the intercalated MT was between 5 and 30%. Unlike what was observed for VT, the intercalated MT materials were recyclable, keeping an excellent performance when reutilized.

Udo Th A Brinkman - One of the best experts on this subject based on the ideXlab platform.

  • ultra trace level determination of polar pesticides and their transformation products in surface and estuarine water samples using column liquid chromatography electrospray tandem mass spectrometry
    Journal of Chromatography A, 1999
    Co-Authors: R J C A Steen, A C Hogenboom, P E G Leonards, Renee A L Peerboom, Wim P Cofino, Udo Th A Brinkman
    Abstract:

    Abstract A method is developed for the determination of polar pesticides and their transformation products [atrazine, deethylatrazine, Deisopropylatrazine, hydroxyatrazine, diuron, 3,4-dichlorophenylmethylurea, 3,4-dichlorophenylurea (DPU), monuron, bentazone, anthranil-isopropylamide, chloridazon, metolachlor] in surface, estuarine and sea water samples at the low ng/l level. Solid-phase extraction is combined off-line with column liquid chromatography–electrospray ionization tandem mass spectrometric detection (LC–ESI-MS–MS). The applicability of two solid-phase materials, i.e., LiChrolut EN cartridges and graphitized carbon black extraction disks, is evaluated. The influence of the organic solvent used in gradient LC, as well as the amount of co-extracted humic material on the ESI process is studied. The eluotropic strength of the organic solvent was found to have a distinct effect on the sensitivity of ESI-MS if coupled with LC gradient separations. Methanol gave much better results than acetonitrile and phenylurea compounds are more susceptible to solvent changes than triazines. Co-extracted humic material causes signal suppression in ESI-MS–MS detection. The degree of suppression depends upon the sample pH and the nature of the samples, i.e., surface or estuarine water. Detection limits in LC–ESI-MS–MS ranged from 0.2 to 2 ng/l, with the exception of DPU (8 ng/l). The applicability of the procedure was demonstrated by analyzing surface and estuarine water.