Click on image to view larger version.
Figure 2. Raman spectra of five-hour-gelled calcium polyphosphate matrices before elution. A blank five-hour-gelled disk (A) and a corresponding cefuroxime-loaded disk (B) showed characteristic peaks for a linear polyphosphate (704 and 1170 cm–1) (Jager and Heyns, 1998) and cefuroxime (1482 and 1600 cm–1), with no apparent interaction (no peak shifts) evident with antibiotic incorporation or compared with the starting compounds (not shown). Note that elevated "noise" or background levels seen between 2500 and 1400 cm–1 in the blank disk spectrum could not be adequately resolved with the available background subtraction software. Non-gelled and 24-hour-gelled disks did not have spectra significantly different from those of the five-hour-gelled disks and, thus, are not shown (n = 1).
