A Simple and Rapid Method to Measure Residue of Cefexime – a Cephalosporin Antibiotic in the Wastewater of Pharmaceutical Production Plant

Abstract

A simple and rapid HPLC method was developed to analyse cefixime, and potentially other cephalosporin antibiotic in wastewater of pharmaceutical production industry. The collected wastewater samples were treated by liquid - liquid extraction using chloroform to eliminate contaminants before instrumental analysis. Separation of the analyte was achieved using a Phenomenex Luna C18 column (250x4.6 mm; 5 μm) and a mixture of methanol and phosphate buffer pH 3.2 as mobile phase in a gradient program. The drug was detected by UV detector at wavelength of 285 nm. The analytical method was first validated using cefixime- spiked samples. Absorbance response to cefixime concentrations is linear from 23 to 1100 ppb with a correlation coefficient > 0.999 and the limit of detection of 6.68 ppb. Repeatability and intermediate precision were tested with RSD of less than 3.0%. The recovery values were found in the range of 97.4-106.0%. The method was then applied to determine concentrations of cefixime in real wastewater samples. The concentrations of cefixime residue measured in the actual samples were in the range of 19.24 to 43.33 ppb which proved the applicability of this analytical method in monitoring the level of contaminated cefixime from the effluent of the pharmaceutical manufacturing plant into environment. The method also showed a potential to apply for other cephalosporin antibiotics.