New Sensitive Kinetic Spectrophotometric Methods for Determination of Omeprazole in Dosage Forms

Table 3

Analytical parameters for the proposed kinetic initial rate methods for determination of OMZ.

Analytical parameters	Iodine method	DDQ method
Linear range (mol)	0.73-8.70×10^−6	1.45-72.4×10^−6
	(0.25-3.00)^a	(0.50-25.00)
Least square equation
(Log𝑉=log𝐾^′+𝑛log𝐶)^b
Intercept (log𝐾^′)±SD	2.68±0.10	3.36±0.03
Slope (n) ±SD	0.87±0.02	0.99±0.01
Correlation coefficient (𝑟)	0.9990	0.9996
LOD^c (mol)	0.24×10^−6 (0.08)	0.41×10^−6 (0.14)
LOQ^c (mol)	0.73×10^−6 (0.25)	1.22×10^−6 (0.42)

a Figures in parenthesis are the quantities in 𝜇g mL⁻¹.
b 𝑉 is the reaction rate, 𝐾^′ is the conditional rate constant, 𝑛 is the order of reaction, and 𝐶 is the molar concentration of OMZ.
c To simplify the calculation of both LOD and LOQ, the simple nonlogarithmic equations [V =0.001(±0.00015)+2093(±45)𝐶] and [V =0.002(±0.00027)+2391(±39)𝐶] were used for both iodine and DDQ methods, respectively, where 𝑉 is the reaction rate and 𝐶 is the molar concentration of OMZ.