Supercritical Fluid Extraction from Soil and HPLC Analysis of Cyanazine Herbicide

Goli, Deepa M.; Locke, Martin A.; Zablotowicz, Robert M.

doi:10.1021/jf960397j

“…teria Zablotowicz et al, 1997;Gould et al, 1985 . Total aerobic heterotrophic bacteria, gram-negative and fluorescent pseudomonads, were enumerated by plat-Ž . Ž .…”

Section: Microbiological Techniquesmentioning

confidence: 99%

“…Analysis was conducted by RAD-HPLC, using parame-Ž . ters described elsewhere Goli et al, 1997 . An adsor-Ž bosphere C18 reverse-phase column 25 cm = 4.6 mm .…”

Section: Cyanazine Metabolismmentioning

confidence: 99%

See 1 more Smart Citation

Fluorescent pseudomonas isolates from Mississippi Delta oxbow lakes: In vitro herbicide biotransformations

Zablotowicz¹,

Locke²,

Hoagland³

et al. 2001

Environmental Toxicology

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Fluorescent pseudomonads were a major component [log (10) 4.2-6.1 colony-forming units mL-1] of the culturable heterotrophic gram-negative bacterioplankton observed in three Mississippi Delta oxbow lakes in this study. Pure cultures of fluorescent pseudomonads were isolated from three Mississippi Delta oxbow lakes (18 per lake), using selective media S-1. Classical physiological tests and Biolog GN plates were used in criteria for taxonomic identification. Most isolates were identified as biotypes of Pseudomonas fluorescens 55% (II), 7% (III), and 25% (V). About 7% of the isolates were identified as P. putida and 7% as non-fluorescent Pseudomonas-like. Cell suspensions of these isolates were tested for their ability to metabolize/co-metabolize six 14C-radiolabeled herbicides (2,4-dichlorophenoxyacetic acid (2,4-D), cyanazine, fluometuron, metolachlor, propanil, and trifluralin) that are commonly used for crop production in this geographical area. Almost all (53 of 54) isolates transformed trifluralin via aromatic nitroreduction. Most isolates (70%) dechlorinated metolachlor to polar metabolites via glutathione conjugation. About 60% of the isolates hydrolyzed the amide bond of propanil (a rice herbicide) to dichloroaniline, with the highest frequency of propanil-hydrolyzing isolates observed in the lake from the watershed with rice cultivation. All propanil-hydrolyzing isolates were identified as P. fluorescens biotype II. No metabolism of cyanazine or fluometuron was observed by any isolates tested, indicating little or no potential for N-dealkylation among this group of bacterioplankton. No mineralization of 2,4-D labeled in either the carboxyl or ring position was observed. These results indicate that reductive and hydrolytic pathways for herbicide co-metabolism (aromatic nitroreduction, aryl acylamidase, and glutathione conjugation) are common in Mississippi Delta aquatic fluorescent pseudomonads; however, the potential for certain oxidative transformations (N-dealkylation, cyano group oxidation) may be rare in this group of bacterioplankton.

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“…Styrene-divinylbenzene polymers characterised by a high degree of cross-linking, an open structure and high porosity increasing their specific area, can be satisfactorily used for the simultaneous preconcentration of parent triazine herbicides and their more polar degradation products [1,5]. Typically, methods developed for the determination of triazine compounds in soil involve an extraction procedure and a clean-up step in order to eliminate the co-extracted interfering soil components and to preconcentrate the analytes for gas chromatographic (GC) [4 -16], high-performance liquid chromatographic (HPLC) [17 -22], and in some cases for thinlayer chromatographic determination [21,23]. The extrac-tion techniques include classical solvent extraction [4, 6 -9], Soxhlet extraction [17,18], sonicated extraction [10, 12 -14, 19, 23], microwave-assisted solvent extraction [11,14,15], pressurised liquid extraction (accelerated solvent extraction) [16], and supercritical fluid extraction (SFE) [20,21].…”

Section: Introductionmentioning

confidence: 99%

“…For the selective preconcentration of analytes extracted from soil the C 18 solid-phase extraction can be used [1, 5 -8, 16, 18], followed, if necessary, by cleaning of the eluate on an anion exchanger [6,18] or silica column [16]. Graphitised carbon black (Carbograph 4) is used for the preconcentration of triazine herbicides extracted from the soil by hot water [21]. The use of immunosorbents is an efficient way to make selective solid-phase extraction of triazine compounds a powerful technique for the determination of more polar compounds [1,17,19].…”

Section: Introductionmentioning

confidence: 99%

Comparison of gas and high performance liquid chromatography with selective detection for determination of triazine herbicides and their degradation products extracted ultrasonically from soil

Stipičević

¹

,

Fingler

²

,

Zupančič‐Kralj

³

et al. 2003

J of Separation Science

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Comparison of gas and high performance liquid chromatography with selective detection for determination of triazine herbicides and their degradation products extracted ultrasonically from soil GC and HPLC with selective detectors were compared for simultaneous determination of triazine herbicides simazine, atrazine, propazine, terbuthylazine, cyanazine, ametryn, prometryn, and atraton, and of their dealkylated degradation products in soil. The compounds were ultrasonically extracted from spiked agricultural soil samples (organic matter content a 5%) with a 2:1 acetone:n-hexane mixture. High efficiency of GC capillary column and high selectivity of the thermionic sensitive detector (TSD) and ion trap detector (ITD) made it possible to directly analyse uncleaned soil extracts and determine all 12 compounds in one run. In reversed-phase HPLC with diode-array detector (DAD), the co-elution of soil matrix components interfered with the determination of methylthiotriazines and terbuthylazine. The recovery of triazine compounds, determined by GC-TSD, from a silty sand soil (organic matter content 1.82%, pH 6.22) spiked at levels of 15 -600 ng g -1 , were 70 -90% (RSD 9 -19%), except for deisopropylatraton (38%). GC-TSD analysis with detection limits of 5 -15 ng g -1 for chloro-and methylthiotriazines and 30 ng g -1 for methoxytriazines was more sensitive than GC-MS(ITD). GC analysis with electron capture detection was sensitive for some chlorotriazines, but a reliable compound quantification in complex chromatograms of uncleaned soil of extracts was not possible. For all compounds save didealkylatrazine, HPLC-DAD was at least two times less sensitive than GC-TSD. Soil/sediment organic matter, clay and silt content, and pH were identified as matrix characteristics which might affect ultrasonic extraction recovery of a particular compound.

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Fluorescent pseudomonas isolates from Mississippi Delta oxbow lakes: In vitro herbicide biotransformations

Zablotowicz¹,

Locke²,

Hoagland³

et al. 2001

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Fluorescent pseudomonads were a major component [log (10) 4.2-6.1 colony-forming units mL-1] of the culturable heterotrophic gram-negative bacterioplankton observed in three Mississippi Delta oxbow lakes in this study. Pure cultures of fluorescent pseudomonads were isolated from three Mississippi Delta oxbow lakes (18 per lake), using selective media S-1. Classical physiological tests and Biolog GN plates were used in criteria for taxonomic identification. Most isolates were identified as biotypes of Pseudomonas fluorescens 55% (II), 7% (III), and 25% (V). About 7% of the isolates were identified as P. putida and 7% as non-fluorescent Pseudomonas-like. Cell suspensions of these isolates were tested for their ability to metabolize/co-metabolize six 14C-radiolabeled herbicides (2,4-dichlorophenoxyacetic acid (2,4-D), cyanazine, fluometuron, metolachlor, propanil, and trifluralin) that are commonly used for crop production in this geographical area. Almost all (53 of 54) isolates transformed trifluralin via aromatic nitroreduction. Most isolates (70%) dechlorinated metolachlor to polar metabolites via glutathione conjugation. About 60% of the isolates hydrolyzed the amide bond of propanil (a rice herbicide) to dichloroaniline, with the highest frequency of propanil-hydrolyzing isolates observed in the lake from the watershed with rice cultivation. All propanil-hydrolyzing isolates were identified as P. fluorescens biotype II. No metabolism of cyanazine or fluometuron was observed by any isolates tested, indicating little or no potential for N-dealkylation among this group of bacterioplankton. No mineralization of 2,4-D labeled in either the carboxyl or ring position was observed. These results indicate that reductive and hydrolytic pathways for herbicide co-metabolism (aromatic nitroreduction, aryl acylamidase, and glutathione conjugation) are common in Mississippi Delta aquatic fluorescent pseudomonads; however, the potential for certain oxidative transformations (N-dealkylation, cyano group oxidation) may be rare in this group of bacterioplankton.

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Supercritical Fluid Extraction from Soil and HPLC Analysis of Cyanazine Herbicide

Cited by 18 publications

References 40 publications

Fluorescent pseudomonas isolates from Mississippi Delta oxbow lakes: In vitro herbicide biotransformations

Fluorescent pseudomonas isolates from Mississippi Delta oxbow lakes: In vitro herbicide biotransformations

Comparison of gas and high performance liquid chromatography with selective detection for determination of triazine herbicides and their degradation products extracted ultrasonically from soil

Fluorescent pseudomonas isolates from Mississippi Delta oxbow lakes: In vitro herbicide biotransformations

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