Application of Cerium (IV) as an Oxidimetric Agent for the Determination of Ethionamide in Pharmaceutical Formulations

Table 1

Sensitivity and regression parameters.

Parameter	Spectrophotometric method
, nm	470
Colour stability	30 min
Linear range, μg/mL	0.5–5.0
Molar absorptivity (ε), L/(mol⋅cm)	2.66 × 10^4
Sandell sensitivity, μg/cm^2	0.0063
Limit of detection (LOD), μg/mL	0.013
Limit of quantification (LOQ), μg/mL	0.043
Regression equation,
Intercept ()	0.0038
Slope ()	0.1591
Standard deviation of ()	9.89 × 10^−2
Standard deviation of ()	2.18 × 10^−2
Regression coefficient ()	0.9989

Limit of determination as the weight in μg/mL of solution, which corresponds to an absorbance of = 0.001 measured in a cuvette of cross-sectional area 1 cm² and = 1 cm. , where is the absorbance, is the concentration in μg/mL, is intercept, and is slope.