Determination of tetracycline in plasma by flow injection method with chemiluminescence detection.

Abstract

Determination of tetracycline (TC) in rabbit plasma was investigated by a flow injection method with chemiluminescence detection. The method consisted of preceding oxidation of the sample material with potassium peroxodisulfide(PPS) and mixing with 1, 3-dibromo-5, 5-dimethylhydantoin (DDH). The chemiluminescence occurred immediately after the mixing of DDH. These processes were assembled in the flow injection system as reported in the previous paper. The optimum concentrations of PPS and DDH were 40 mM and 18 mM (in 0.1 M NaOH solution), respectively, at 25 °C at the flow rate of 2.0 ml/min. The linear range for determination of the standard sample in aqueous solution was 0.042.5 nmol (0.3622 μg/ml with 50 μl sample) with relative standard deviation of 2.0 % (within-run at 0.31 nmol, n=10). The solvent extraction of the Ca(II) chelate was applied to the plasma sample with 80 % recovery. The linear range of determination in this case was 0.132.1 nmol (1.219 μg/ml with 40 μl plasma sample). The sensitivity was satisfactory for the drug-level monitoring of TC, when 100 μl sample was used for one injection.