Table 2: Sensitivity and regression parameters.

ParameterMethod BMethod C

, nm460470
Colour stability, min6015
Linear range, g mL−10.4–8.00.4–10
Molar absorptivity ( ), L mol−1 cm−14.0 × 1043.7 × 104
Sandell sensitivity*, g cm−20.01050.0136
Limit of detection (LOD), g mL−10.390.43
Limit of quantification (LOQ), g mL−11.191.32
Regression equation,
 Intercept ( )0.87440.8082
 Slope ( )−0.0914−0.0815
 Standard deviation of ( )2.2 × 10−26.6 × 10−2
 Standard deviation of ( )4.9 × 10−37.3 × 10−3
 Regression coefficient ( )−0.9998−0.9990

Limit of determination as the weight in g per mL of solution, which corresponds to an absorbance of measured in a cuvette of cross-sectional area 1 cm2 and = 1 cm. , where is the absorbance, is concentration in g mL−1, is intercept, and is slope.