Application of Samarium- and Terbium-Sensitized Luminescence via a Multivariate-Based Approach for the Determination of Orbifloxacin

Table 9

Determination of ORLX in the formulation under the optimum conditions. Direct calibration and standard addition methods were performed.

	ORLX-Sm(III)		ORLX-Tb(III)
Direct calibration method
Taken (ng/mL)	Found (ng/mL)	% recovery	Found (ng/mL)	% recovery
25.00	24.83	99.31	25.54	102.16
50.00	48.75	97.50	49.15	98.30
100.0	96.40	96.40	100.09	100.09
200.0	208.57	104.29	198.20	99.10
300.0	298.66	99.55	304.27	101.42
400.0	397.78	99.45	397.75	99.44
Mean ± SD		99.42 ± 2.70		100.09 ± 1.46
RSD	2.72	1.46
Standard addition method
Taken (ng/mL)	Added (ng/mL)	% recovery	Added (ng/mL)	% recovery
100.0	—	95.64	—	96.67
100.0	50	96.26	50	102.76
100.0	100	100.37	100	103.99
100.0	150	99.24	150	98.87
100.0	200	102.16	200	97.22
100.0	250	100.15	250	101.69
100.0	300	98.97	300	100.88
Mean ± SD		99.64 ± 2.16		100.91 ± 2.79
RSD		2.17		2.77