2-Hydroxy-1-naphthaldehyde-P-hydroxybenzoichydrazone: A New Chromogenic Reagent for the Determination of Thorium(IV) and Uranium(VI)

Table 5

Analysis of phosphate rock and fertilizers for their uranium content.

	Uranium content (mg kg^−1)
Sample	Proposed method ± SD	AAS method ± SD
	(𝑛=4)	(𝑛=2)
Phosphate rock; (India)	33.96 ± 0.032	35.26 ± 0.018
NPK fertilizer	19.25 ± 0.010	17.95 ± 0.012
DAP fertilizer	49.95 ± 0.024	50.06 ± 0.022