Table 4: Method robustness and ruggedness expressed as intermediate precision.

Method KTF taken
mg/µg mL−1
RobustnessRuggedness
H2SO4 volume, mL
(% RSD),
Reaction time, min
(% RSD),
Ineranalysis (% RSD), Intercuvettes/burettes (% RSD),

A5.00.881.630.810.85
10.01.331.831.931.23
15.01.030.590.890.96

B2.02.602.112.112.38
4.02.711.362.631.82
6.01.791.801.582.83

C4.02.662.702.012.71
6.02.451.832.791.99
8.01.721.271.692.96

In titrimetry, standing times were 8, 10, and 12 min.
In spectrometric methods B and C, reaction time, 10 ± 1 min; volume of H2SO4 2 ± 0.2 mL and 1 ± 0.2 mL varied, respectively.