Analysis for paraquat by second- and fourth-derivative spectroscopy.

Abstract

We describe simple, precise methods, based on second and fourth-derivative spectroscopy, of analysis for paraquat in serum, plasma, or dialysis fluid. Plasma paraquat, after ion-pair extraction and dithionite reduction, yields a sharp, stable absorption peak at 396 nm. Derivative spectroscopy confers enhanced sensitivity (detection limit, 5 microgram/L) and improved rejection of spectroscopic interference by diquat, hemolysis, bilirubin, or lipemia. Derivative peak amplitudes are linearly related to paraquat dichloride concentration from 10 to 1000 microgram/L in plasma, and the methods are precise (CV 2.7-5.2% for 50 microgram/L concentration) and accurate. Results of derivative assays for 18 cases of paraquat poisoning correlate well with those by radioimmunoassay (r = 0.999). Derivative spectroscopy enables monitoring of paraquat concentrations in the plasma of poisoned patients during treatment by hemoperfusion or hemodialysis. A rapid assay developed for dialysis fluid (detection limit, 2 microgram/L) permits the efficacy of hemodialysis to be routinely assessed.

• Authors: A F Fell, D R Jarvie, M J Stewart
• Journal: Clinical chemistry (Clin Chem) Vol. 27 Issue 2 Pg. 286-92 (Feb 1981) ISSN: 0009-9147 [Print] England
• PMID: 7460281 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Indicators and Reagents
• Dithionite
• Diquat
• Paraquat

Topics

• Diquat (analysis)
• Dithionite
• Humans
• Indicators and Reagents
• Paraquat (analysis, blood)
• Radioimmunoassay (methods)
• Renal Dialysis
• Spectrophotometry (methods)