A rapid, enzymatic method for the determination of chloramphenicol in serum

A simple, rapid assay of serum chloramphenicol has been developed which combines the specificity of the enzyme chloramphenicol acetyltransferase with the convenience of a colorimetric detection system. The assay is linear over the drug concentration range 5-200 microM (1.5-65 mg/l) and therefore is suitable for detection below and above the therapeutic range (31-62 microM, 10-20 mg/l with potential toxicity above 75 microM, 24 mg/l). This method does not detect the microbiologically inactive succinate or palmitate pro-drugs of chloramphenicol and evidence suggests that the major metabolite, chloramphenicol glucuronide also is not detected. Good correlation with an HPLC method has been achieved (r = 0.9860). The assay is based on a two reagent system with very simple methodology, the only instrumentation required being a spectrophotometer. However, the assay could be adapted to run on a range of discrete analysers.