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

Table 1

Tolerance limits of foreign ions. Amount of Th(IV) taken = 0.928 μg mL⁻¹ pH = 6.0.

Foreign ion	Tolerance limit; (μg mL^−1)	Foreign ion	Tolerance limit; (μg mL^−1)	Foreign ion	Tolerance limit; (μg mL^−1)
Iodide	1904	Ba(II)	1650	Hg(II)	20
EDTA	1861	Na(I)	1500	Ru(III)	20
Thiosulphate	1680	K(I)	1400	Mn(II)	11
Sulphate	1440	Ca(II)	1140	Zr(IV)	10
Bromide	1215	Mg(II)	1000	Sn(II)	10
Citrate	945	W(VI)	55	Sr(II)	9
Nitrate	930	Hf(IV)	54	Cr(VI)	6
Tartrate	740	Pb(II)	42	Cu(II)	5
Thiocyanate	870	Ti(IV)	40	Ni(II)	<1, 55^a
Carbonate	600	Au(III)	40	Co(II)	<1, 100^a
Chloride	533	Te(IV)	40	Zn(II)	<1, 60^a
Phosphate	475	Cd(II)	34	Bi(III)	<1, 150^a
Thiourea	380	Se(IV)	31	Fe(II)	<1, 60^a
Oxalate	280	Mo(VI)	29	Al(III)	<1, 120^b
Fluoride	95	La(III)	28	U(VI)	<1, 70^b
		Pd(II)	22	In(III)	<1, 50^b
		Ag(I)	22	Ga(III)	<1, 60^b

Masking agents, ^ain the presence of 800 ppm of EDTA; ^b500 ppm of tartrate.