Ion

Molar excess of the ion

Masking agent

Found Nb, µg

RSD, %

Ascorbic acid         

100

30.3

2

Tartaric acid         

100

30.4

5

Oxalate         

5

30.8

4

Fluoride         

1.5

29.6

4

Phosphoric acid         

30

30.4

3

Thiourea         

20

31.2

6

Co(II)

120

30.0

5

Ni(II)

120

30.2

3

Al(III)

190

29.8

4

Fe(II)

60

29.6

4

Fe(III)

60

30.2

4

Cd(II)

200

30.2

4

Zr(IV)

75

NaF

30.5

5

Cu(II)

25

SC(NH₂)₂

29.7

5

Ti(IV)

5

Ascorbic acid

29.6

3

Mn(II)

40

29.9

4

W(VI)

8

29.8

4

Mo(VI)

15

29.6

5

Cr(III)

30

30.2

2

V(IV)

10

30.2

6

Ta(V)

5

NaF

30.4

3

Pt(II)

50

29.2

5

Pd(II)

50

30.4

4

40

CH₃COO⁻

29.5

3