Microvolume-DLLME for the Spectrophotometric Determination of Clidinium Bromide in Drug, Urine, and Serum

The present study combines UV-Vis spectrophotometry and dispersive liquid-liquid microextraction
(DLLME) for the preconcentration and determination of trace level clidinium bromide (Clid) in
pharmaceutical preparation and real samples. The method is based on ion-pair formation between Clid
and bromocresol green in aqueous solution using citrate buffer (pH = 3). The colored product was first
extracted using a mixture of 800 μL acetonitrile and 300 μL chloroform solvents. Then, a spectrophotometric
measurement of sediment phase was performed at λ = 420 nm. The important parameters affecting the
efficiency of DLLME were optimized. Under the optimum conditions, the calibration graphs of standard
(Std.), drug, urine and serum were ranged 0.005 - 0.16 μg mL-1. The limits of detection, quantification, and
Sandell's sensitivity were calculated. Good recoveries of Clid Std., drug, urine and serum at 0.005, 0.01,
0.1 and 0.16 μg mL-1 ranged 93.77 - 101.0%. Enrichment factor was calculated for Std., drug, urine and
serum. The method was applied successfully to determine Clid in pharmaceutical preparation and real
samples.