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Recently the authors' laboratory reported on the use of a newly developed ferrous detection reagent [1]. This reagent, 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine-p,p'-disulfonic acid, disodium salt trihydrate (PDT), reacts with ferrous ion to give a magenta complex, and the reaction is sufficiently sensitive to be used to determine if an individual has recently handled a steel object such as a firearm.
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Thornton et al. (1977) studied this question.
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