Rapid immunological assay methods for ceftazidime and alcalase in the workplace atmosphere

Rapid ELISAs are reported for the protease enzyme, alcalase, and the cephalosporin, ceftazidime. Both assays have the sensitivity, specificity, precision and speed necessary for rapid analysis (25–45 min for 40 samples) of samples eluted from filters following sampling of airborne aerosols in the workplace. Recovery of the analytes from spiked filters showed near quantitative recovery for alcalase with glass fibre filters and for ceftazidime with PTFE filters. Under controlled release conditions for aerosols at a concentration corresponding to the Occupational Exposure Standard for ceftazidime, use of glass fibre, PTFE and polycarbonate filters all gave poor recovery ranging from 34.6 to 59.2% when analysed by ELISA and HPLC. Evidence is provided that ceftazidime undergoes hydrolysis on exposure to glass-fibre filters.