The sodium dithionite test in urine confirms this toxin?
In a patient with paraquat or diquat poisoning, their urine will turn blue or green, respectively when sodium dithionite in sodium hydroxide is added to their urine.
Koo JR et al. Rapid analysis of plasma paraquat using sodium dithionite as a predictor of outcome in acute paraquat poisoning. Am J Med Sci 2009; 338:373-377. Salazar A et al. Colorimetic detection of urinary diquat: in vitro demonstration. Clin Tox 2007; 45:381-382.