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J Med Toxicol. 2010 March; 6(1): 35–36.
Published online 2010 March 13. doi:  10.1007/s13181-010-0033-6
PMCID: PMC2861174

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.

Keywords: Diquat, Herbicide toxicity, Bedside diagnosis

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.
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