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

Abstract

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.

Gas chromatographic–mass spectrometric method for the determination of the herbicides paraquat and diquat in plasma and urine samples

“…For quantitative measurements, high-performance liquid chromatography (HPLC) or liquid chromatography coupled with mass spectrometry (LC-MS) are the main techniques used [4,8,[13][14][15][16]. Other analytical techniques such as capillary electrophoresis and immunoassay were also proposed in methods to detect these herbicides in biological matrices [17,18].…”

Paper-based diagnostic devices for clinical paraquat poisoning diagnosis

“…15 Various analytical methods to quantify PQ level in serum or plasma have been proposed, including high performance liquid chromatography (HPLC)/mass spectrometry (MS), gas chromatography (GC)/MS, capillary electrophoresis, enzyme-linked immunosorbent assay (ELISA), and spectrophotometry coupled with a sodium dithionite assay. 12,[15][16][17][18][19] Most of them, however, are time consuming and require complicated operational settings and experimental preparations.…”

Quantification of paraquat in postmortem samples by gas chromatography–ion trap mass spectrometry and review of the literature

“…Quaternary ammonium herbicides are polar, easily soluble in water and nonvolatile. Owing to these properties and to the cationic character, these herbicides are suitable for separation and analysis by CE (Vinner et al , ; Nunez et al , , , , , ). Paraquat, DQ and DF have been quantified by CE coupled to UV detection in biological matrices such as urine, serum, water, and soil (Vinner et al , ; Nunez et al , ).…”

“…Owing to these properties and to the cationic character, these herbicides are suitable for separation and analysis by CE (Vinner et al , ; Nunez et al , , , , , ). Paraquat, DQ and DF have been quantified by CE coupled to UV detection in biological matrices such as urine, serum, water, and soil (Vinner et al , ; Nunez et al , ). CE together with mass spectrometry (CE/MS) increases the selectivity and sensitivity and has been reported for water samples (Nunez et al , ).…”