Spectrophotometric determination of diquat and paraquat in aqueous herbicide formulations

Yuen, S. H.; Bagness, J. E.; Myles, D.

doi:10.1039/an9679200375

Cited by 89 publications

(32 citation statements)

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“…Various methods have been applied to the analysis of these herbicides. Sodium dithionite reaction allows qualitative detection of PQ and DQ in urine or gastric fluid (Berry and Grove, 1971;Yuen et al, 1967). For serum or urine spectrophotometric methods are used (Knepil, 1977;Tayama et al, 1991;Kesari et al, 1997) or derivated spectrophotometric methods (O'Haver, 1979;Fell et al, 1981;Jarvie et al, 1981;Fuke et al, 1992), chromatographic analysis-highperformance liquid chromatography (Miller et al, 1979;Gill et al, 1983;Nakagiri et al, 1989;Ito, 1993), gas chromatography (Martens and Heynfrickse, 1974;Kawase et al, 1984) or gas chromatography-mass spectrometric methods (Draflan et al, 1977), radioimmunologic assays (Levitt, 1979;Fatori and Hunter, 1980) and RMN 1 H (Imbenotte et al, 1999).…”

Section: Introductionmentioning

confidence: 99%

Separation and quantification of paraquat and diquat in serum and urine by capillary electrophoresis

Vinner

Stievenart

Humbert

et al. 2001

Biomedical Chromatography

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The use of capillary electrophoresis (CE) for simultaneous qualitative and quantitative detection of paraquat (PQ) and diquat (DQ) in both serum and urine was investigated. The two herbicides were extracted from biological fluids with liquefied phenol. Serum required a deproteinization with chloroform and ammonium sulfate as pretreatment. The extracts were hydrodynamically injected and the complete separation was carried out in 10 min, using a capillary tube (75 microm i.d., 500 mm) of fused silica containing 50 mM phosphate buffer (pH 2.50) as the carrier. UV absorbance detection at 200 nm was performed by an on-column detector. The analytes were characterized by their respective migration times. Analytical recoveries were 52.6% for PQ and 62.6% for DQ in serum, and 71.4% and 59.3%, respectively, in urine. The linearity was studied up to 4 mg/L and the limits of detection (LODs) were better than 5 pg/mL in serum or urine. The CE method described was applied to the characterization of two lethal poisonings and results were related.

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Section: Introductionmentioning

confidence: 99%

Separation and quantification of paraquat and diquat in serum and urine by capillary electrophoresis

Vinner

Stievenart

Humbert

et al. 2001

Biomedical Chromatography

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“…The extraction constant (K ex ) is expressed by (2) The distribution ratio of PQ is represented by If the concentrations of PQ 2+ ·BPE -and PQ 2+ ·2TBPE -are negligibly low compared with that of PQ 2+ in the aqueous phase, Eq. (3) can be written as…”

Section: (6) Composition Of Extracted Pq-tbpe and Dq-tbpementioning

confidence: 99%

“…Poisoning cases are occasionally encountered due to accidental and intentional ingestion. Many methods such as spectrophotometry [1][2][3][4][5][6] , liquid chromatography 7-10 , flow-injection 11 , gas chromatography 12 , and electrochemistry 13,14 for the determination of PQ in biological samples have been reported.Most of these methods require a complicated and time-consuming sample pretreatment. Furthermore, most spectrophotometric methods are based on its reduction to a blue radical with alkaline sodium dithionite.…”

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Highly Sensitive Determination of Paraquat and Diquat in Human Blood with Tetrabromophenolphthalein Ethyl Ester by Ion-Pair Extraction/Spectrophotometric Method

et al. 1999

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Paraquat (1,1′-dimethyl-4,4′-dipyridinium, PQ), which is toxic to humans, has been widely used as a herbicide. Poisoning cases are occasionally encountered due to accidental and intentional ingestion. Many methods such as spectrophotometry [1][2][3][4][5][6] , liquid chromatography 7-10 , flow-injection 11 , gas chromatography 12 , and electrochemistry 13,14 for the determination of PQ in biological samples have been reported.Most of these methods require a complicated and time-consuming sample pretreatment. Furthermore, most spectrophotometric methods are based on its reduction to a blue radical with alkaline sodium dithionite.2 The blue-color development, however, is unstable.Since the commercially available PQ herbicide is a mixture of PQ and DQ, it is worth developing a simple spectrophotometric method for a highly sensitive determination of PQ and DQ for forensic and clinical purposes as preliminary screening. PQ reacts with TBPE to provide an organic solvent extractable, blue-color PQ-TBPE. 15 We found that DQ can be extracted with TBPE into dichloromethane as well as PQ, and that PQ-TBPE gives a slightly different absorption spectrum from that of DQ-TBPE. In this work, an ion-pair extraction/spectrophotometric determination of the total amounts of PQ and DQ in human blood sample using TBPE was developed. Experimental ReagentsThe PQ and DQ used as standards were biochemical reagents from Wako Chemical Industry. TBPE was supplied by Kanto Chemical Co. Ltd. A standard solution of 3.00×10 -3 M (1 M=1 mol dm -3 ) TBPE was prepared by dissolving 52.5 mg of TBPE in a waterethanol (50:50(v/v)%) solution. Sodium tetraborate (0.2 M)-sodium hydroxide (0.1 M) buffer solutions were used to adjust the pH. The concentration of tetraborate was fixed at 0.02 M. A Sep-Pak C 18 cartridge (500 mg) was obtained from Waters Associates (Milford, MA, USA). Water was distilled and deionized with a Milli-Q system (Milli-Q SP. TOC., Millipore). All other chemicals were of reagent grade and were used without further purification. ApparatusThe absorption spectra and absorbances were measured by a JASCO V-560 UV/VIS spectrophotometer using a quartz cell with an optical path length of 1.0 cm. The pH measurements were carried out using a Radiometer PHM 93 pH meter. A mechanical shaker (Iwaki) was used to equilibrate the extraction vials. All of the experiments were carried out at 25˚C in a thermostated room. Extraction procedure of PQ and DQPrior to the extraction of PQ and DQ in human blood with TBPE into dichloromethane, each blood sample was deproteinized with 0.23 M perchloric acid, followed by an ultrasonic treatment. PQ and DQ in the sample solution were extracted with a Sep-Pak C 18 cartridge according to an almost similar procedure to that discussed in a reference. 16 The pH of the deproteinized sample solution (1 ml) was adjusted to about pH 11 with a sodium hydroxide solution. The sample was injected into a Sep-Pak C 18 cartridge pre-conditioned with 5 ml of water, 5 ml of methanol and 20 ml of water. Three milliliters of dist...

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“…Then the culture medium was centrifuged at 16,000 rpm for 10 min and glucose was assayed in a small portion (4 jl) of the resulting supernatant using a commercial assay system (Boehringer/Mannheim). Dgquat in the supernatant was determined by measuring UV absorption at 310 nm (13). Paraquat was determined by measuring absorption at 600 nm after reduction with alkaline sodium dithionite (13).…”

mentioning

confidence: 99%

“…Dgquat in the supernatant was determined by measuring UV absorption at 310 nm (13). Paraquat was determined by measuring absorption at 600 nm after reduction with alkaline sodium dithionite (13).…”

mentioning

confidence: 99%

Degradation of paraquat and diquat by the yeast Lipomyces starkeyi.

Shirata

Takagishi

1986

J. Gen. Appl. Microbiol.

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Spectrophotometric determination of diquat and paraquat in aqueous herbicide formulations

Cited by 89 publications

References 0 publications

Separation and quantification of paraquat and diquat in serum and urine by capillary electrophoresis

Separation and quantification of paraquat and diquat in serum and urine by capillary electrophoresis

Highly Sensitive Determination of Paraquat and Diquat in Human Blood with Tetrabromophenolphthalein Ethyl Ester by Ion-Pair Extraction/Spectrophotometric Method

Degradation of paraquat and diquat by the yeast Lipomyces starkeyi.

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