Table 4: Robustness and ruggedness.

Method AMethod BMethod C
STS studied mgRobustness (RSD, %)
Volume of HCla ( )
Ruggedness (RSD, %)
Interburettes ( )
STS studied µg mL−1 Robustness (RSD, %)
Conditions altered
Ruggedness (RSD, %) STS studied
µg mL−1
Robustness (RSD, %)
Conditions altered
Ruggedness (RSD, %)
Volume of HCla
( )
Reaction timeb ( )Intercuvettes
( )
Volume of HCla  
( )
Reaction timeb
( )
Intercuvettes
( )

4.000.771.156.001.701.952.271.001.391.511.93
6.001.010.899.002.121.722.152.001.861.832.08
8.000.931.0012.01.371.441.973.001.401.281.89

In method A, volumes of 2 M HCl varied were 5 ± 1 mL; in both methods B and C, 2 M HCl (1 mL ± 0.1 mL).
bIn both methods B and C, the reaction time employed was 15 ± 1 min.