Sensitive Spectrophotometric Determination of Atenolol in Pharmaceutical Formulations Using Bromate-Bromide Mixture as an Eco-Friendly Brominating Agent

Table 2

Regression and analytical parameters.

Parameter	Method A	Method B	Method C
𝜆max, nm	540	445	630
Beer’s law limits (μg/mL)	1–20	2–40	1–8
Molar absorptivity (L/mol · cm)	1.20×10^4	4.51×10^3	3.46×10^4
Sandell sensitivity* (μg/cm^2)	0.0223	0.0591	0.0077
Limit of detection (μg/mL)	0.12	0.56	0.05
Limit of quantification (μg/mL)	0.36	1.69	0.14
Regression equation, 𝑌^∗∗
Intercept	0.0038	0.7755	0.0217
Slope	0.0443	−0.0154	0.1229
Correlation coefficient (r)	0.9996	−0.9973	0.9992
Standard deviation of intercept (𝑆𝑎)	0.00664	0.08471	0.01436
Standard deviation of slope (𝑆𝑏)	0.00059	0.00378	0.00292

*Limit of determination as the weight in 𝜇g per ml of solution, which corresponds to an absorbance of 𝐴=0.001 measured in a cuvette of cross-sectional area 1 cm² and l = 1 cm. ^∗∗𝑌=𝑎+𝑏𝑋, where 𝑌 is the absorbance, a is the intercept, b is the slope, and X is the concentration in 𝜇g/mL.