Sorption mechanisms of cephapirin, a veterinary antibiotic, onto quartz and feldspar minerals as detected by Raman spectroscopy.
Raman spectroscopy was used to investigate sorption mechanisms of cephapirin (CHP), a veterinary antibiotic, onto quartz (SiO(2)) and feldspar (KAlSi(3)O(8)) at different pH. Sorption occurs by electrostatic attraction, monodentate and bidentate complexation. The zwitterion (CHP(o)) adsorbs to a quartz((+)) surface by electrostatic attraction of the carboxylate anion group (-COO(-)) at low pH, but adsorbs to a quartz((-)) surface through electrostatic attraction of the pyridinium cation, and possibly COO(-) bridge complexes, at higher pH. CHP(-) bonds to quartz((-)) surfaces by bidentate complexation between one oxygen of -COO(-) and oxygen from carbonyl of an acetoxymethyl group. On a feldspar((+/-)) surface, CHP(o) forms monodentate complexes between CO, and possible -COO(-) bridges and/or electrostatic attachments to localized edge (hydr)oxy-Al surfaces. CHP(-) adsorbs to feldspar((-)) through monodentate CO complexation. Similar mechanisms may operate for other cephalosporins. Results demonstrate, for the first time, that Raman techniques can be effective for evaluating sorption mechanisms of antibiotics.
Peterson
Jonathan W
JW
Department of Geological & Environmental Sciences, Hope College, P.O. Box 9000, Holland, MI 49422-9000, USA. peterson@hope.edu
O'Meara
Theresa A
TA
Seymour
Michael D
MD
Wang
Wei
W
Gu
Baohua
B
D000327:Adsorption; D000538:Aluminum Silicates; D000900:Anti-Bacterial Agents / Q000032:analysis*; D002514:Cephapirin / Q000032:analysis*; D054750:Ecotoxicology / Q000379:methods; D004785:Environmental Pollutants / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D017680:Potassium Compounds; D011791:Quartz; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman / Q000379:methods; D019155:Veterinary Drugs / Q000032:analysis*
D000538:Aluminum Silicates; D000900:Anti-Bacterial Agents; D004785:Environmental Pollutants; D017680:Potassium Compounds; D019155:Veterinary Drugs; C016447:feldspar; D011791:Quartz; D002514:Cephapirin