A Spectrophotometric Flow Injection Method for Determination of Ultratrace Amounts of Phenylhydrazine by Its Inhibition Effect on the Reaction of Thionin and Nitrite

Table 3

Effect of foreign ions on the determination of 8 nM phenylhydrazine.

Foreign species	Tolerated ratio 𝑊Species/𝑊Phenylhydrazine
NO3−, SO32−, Cl^−, BO33−, ClO3−, Br^−, IO4−, SCN^−, S2O82−, CO32−, PO43−, I^−, CH3COO^−, IO3−, Na^+, K^+, Ba^2+, Fe^2+, Cr^3+, Mn^2+, Hg^2+, Cu^2+, Al^3+, Ag^+, Zn^2+	1000
Mg^2+, Mo^6+, V^5+, Rh^3+, S2O32−, Pd^2+, Ru^3+	800
Ni^2+, Se^4+	500
Pb^2+, Co^2+	200
Cd^2+	100
N2H4	50