Prosedure

, %

RSD, %

СВТ-2 (0.012%Nb)

Standard method

Bromopyrogallol red

(1.29 ± 0.032) × 10⁻²

2.8

Rodanid

(1.27 ± 0.025) × 10⁻²

2.9

Proposed method

DTP + AP₁

(1.23 ± 0.023) × 10⁻²

2.2

DTP + AP₂

(1.23 ± 0.032) × 10⁻²

2.3

DTP + AP₃

(1.24 ± 0.027) × 10⁻²

2.2

СВТ-3 (0.029%Nb)

Standard method

Rodanid

(3.18 ± 0.30) × 10⁻²

2.8

Bromopyrogallol red

(3.14 ± 0.27) × 10⁻²

2.8

Proposed method

DTP + AP₁

(2.84 ± 0.24) × 10⁻²

1.9

DTP + AP₂

(2.91 ± 0.26) × 10⁻²

1.8