APPLICATION OF TOTALLY AUTOMATED ONLINE SAMPLE CLEAN UP SYSTEM FOR EXTRACTION AND HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY SEPARATION OF PEPTIDE LEUKOTRIENES

We have developed a fully automated on-line extraction-purification me thod for peptide leukotrienes in biological fluids using a column-swit ching technique. Individual leukotrienes in HPLC-collected fractions a re determined by immunoassay techniques. Leukotrienes were extracted f rom nasal lavage samples and eluted from the solid-phase extraction ca rtridge into the HPLC column with methanol-ammonium acetate buffer (60 :40, v/v) pH 5.4, as a mobile phase. This method provides good recover ies, excellent resolution of leukotrienes and is suitable to be combin ed with off-line radioimmunoassay (RIA) or enzymoimmunoassay (EIA). Th e most important losses are observed after evaporation-concentration a nd lyophilization. We also have compared RIA with EIA determination. S ignificant differences are found between RIA values and EIA values.