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

Table 9

Analysis of environmental water samples.

Sample	Uranium added	Uranium found (μg mL^−1) ± SD*
	(μg mL^−1)	Found	Recovery (%)
Tap water	0.5	0.51 ± 0.010	102.0
	2.5	2.48 ± 0.016	99.2
	5.0	4.96 ± 0.018	99.2
Well water	0.5	0.49 ± 0.013	98.0
	2.5	2.47 ± 0.018	98.8
	5.0	4.97 ± 0.011	99.4
Waste water	0.5	0.48 ± 0.018	96.0
	2.5	2.52 ± 0.022	100.8
	5.0	4.98 ± 0.013	99.6

*Average of four determinations.