Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9743754 | Analytica Chimica Acta | 2005 | 7 Pages |
Abstract
In aqueous medium of pH 5.33, penicillin, such as ampicillin (AmP), benzyl penicillin (BP), oxacillin (OA) and amoxycillin (AmO), interacts with berberine (BB), forming ion associates through electrostatic attraction of the polar head groups of penicillin and BB. The formed ion associates are then adsorbed into the amphiphilic H2O/CCl4 interfaces, displaying greatly enhanced total internal-reflected resonance light scattering (TIR-RLS) signals with the maximum peak at 370 nm. With the enhanced TIR-RLS data, thermodynamic parameters of adsorption of penicillin-BB ion associates into interfaces were measured. Mechanism studies show that the ion associates of penicillin with BB at H2O/CCl4 interfaces have 1:1 binding molar ratio, and the formation constants are in the range of 3.67 Ã 104 to 5.48 Ã 104 molâ1 dm4. It was found that the enhanced TIR-RLS intensity was directly proportional to the concentration of penicillin in the range of 0.98 Ã 10â7 to 10.0 Ã 10â7 mol lâ1 for BP, 0.87 Ã 10â7 to 10.0 Ã 10â7 mol lâ1 for OA, 1.1 Ã 10â7 to 12.0 Ã 10â7 mol lâ1 for AmP and 1.2 Ã 10â7 to 12.0 Ã 10â7 mol lâ1 for AmO with the corresponding limits of determination (3Ï) being 3.48 Ã 10â8, 3.85 Ã 10â8, 4.22 Ã 10â8 and 4.86 Ã 10â8 mol lâ1, respectively.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Cheng Zhi Huang, Ping Feng, Yuan Fang Li, Ke Jun Tan, Hui Ying Wang,