Kinetic Spectrophotometric Determination of Gemifloxacin Mesylate and Moxifloxacin Hydrochloride in Pharmaceutical Preparations Using 4-Chloro-7-nitrobenzo-2-oxa-1,3-diazole

Table 3

Experimental and analytical parameters for the kinetic spectrophotometric determination of GMF and MOX.

Parameter	GMF	MOX
pH and volume of borate buffer	pH 9.0/0.4 mL	pH 8.5/0.4 mL
Volume of 5.0×10^−3 M NBD-Cl (mL)	1.0	0.8
Temperature (°C)	70	70
Reaction time (min.)	20	15
Solvent	50% (v/v) aqueous acetone	50% (v/v) aqueous acetone
𝜆max (nm)	466	464
Concentration range (M)	1.029×10^−6--1.65×10^−5	4.57×10^−6--2.74×10^−5
Concentration range (𝜇g mL^−1)	0.5–8.0	2.0–12
Molar absorptivity (𝜀) (L mol^−1 cm^−1)	4.0892×10^4	3.48535×10^4
Sandell’s sensitivity (ng cm^−2)	11.87	12.56
Regression equation^a
Slope	0.0972	0.0802
Intercept	0.0068	−0.0039
Correlation coefficient (𝑟)	0.9999	0.9998
LOD (M), (𝜇g mL^−1)	2.47×10^−7, (0.12)	8.22×10^−7, (0.36)
LOQ (M), (𝜇g mL^−1)	8.24×10^−7, (0.4)	2.74×10^−6, (1.2)
Recovery % ± SD	100.03±0.87	99.99±1.24
RSD%	0.87	1.24
RE%	0.91	1.30
𝑡-value^b	0.21 (2.57)	0.38 (2.78)
𝐹-value^b	2.03 (5.05)	2.07 (5.19)

^a𝐴 = a + bC, where 𝐶 is the concentration in 𝜇g mL⁻¹.
^bTheoretical value for 𝑡 and 𝐹 at 95% confidence level at 𝑃=0.05.