| Popis: |
Penicillins can be detected in milk samples using pulsed amperometric detection following reversed-phase high performance liquid chromatography. A detection limit of 210−6 M was achieved for penicillin G, with similar values obtained for the other penicillins tested. To improve these detection limit values, an on-column dual-solvent concentration scheme was adapted. A concentrating solvent forced the deposition of penicillins onto the C-18 column. Afterward, the normal chromatographic eluent carried the nenicillins off the stationary phase and allowed a separation. Work with standard solutions proved the viability of the scheme and also demonstrated the linearity of detector response at low concentrations. Using the concentration procedure, a detection limit of 2 10−7 M was found for penicillin G in milk solution, and in general the concentration scheme allowed detection limits for all of the penicillins to be improved by approximately a factor of 10. |
