The poison pen: bedside diagnosis of urinary diquat.
Diquat is a bipyridyl herbicide with nephrotoxic effects. This in vitro study demonstrates a colorimetric test for detection of diquat in human urine. Urine specimens using ten concentrations of diquat herbicide solution and controls for urine and glyphosate were prepared. A two-step assay (addition of bicarbonate followed by sodium dithionite) was performed, with a resulting color change of the original solution for each specimen. Color change intensity was noted immediately and after 30 min, by gross visual inspection. A green color with concentration-dependent intensity was detected in all specimens, in which concentrations of diquat solution ranged from 0.73 to 730 mg/L. This colorimetric effect disappeared after 30 min. The sodium bicarbonate/dithionite test may be useful as a qualitative bedside technique for the detection of urinary diquat in the appropriate clinical setting.
Department of Emergency Medicine, UCSF-Fresno Medical Center, 155 N. Fresno Drive, Fresno, CA 93701, USA. raisvohra@hotmail.com
Rais
R
Vohra
Anthony
A
Salazar
F L
FL
Cantrell
Ravindra
R
Fernando
Richard F
RF
Clark
D015415:Biomarkers / Q000652:urine; D003124:Colorimetry; D004178:Diquat / Q000506:poisoning* / Q000652:urine*; D004227:Dithionite / Q000737:chemistry; D006540:Herbicides / Q000506:poisoning* / Q000652:urine*; D006801:Humans; D019095:Point-of-Care Systems; D011041:Poisoning / Q000175:diagnosis / Q000652:urine; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D017693:Sodium Bicarbonate / Q000737:chemistry
D015415:Biomarkers; D006540:Herbicides; D004227:Dithionite; D017693:Sodium Bicarbonate; D004178:Diquat