ISOLATION, TRACE ENRICHMENT AND LIQUID-CHROMATOGRAPHIC ANALYSIS OF DIACETYLPHLOROGLUCINOL IN CULTURE AND SOIL SAMPLES USING UV AND AMPEROMETRIC DETECTION

A reversed-phase approach is described for the preparative-scale isolation of the biotechnologically important antibiotic compound 2,4-diacetylphloroglucinol (DAPG), using solid-phase extraction and medium-pressure liquid chromatography. Using the purified sample, a high-performance liquid chromatographic assay was developed for the determination of DAPG in complex matrices such as growth media and soil. A sample pretreatment procedure involving solid-phase extraction on octadecyl silica prior to analytical high-performance liquid chromatography, removed endogenous peaks from the chromatogram when UV (254 nm) and amperometric detection (1.1 V vs. Ag/AgCl) were used. The reversed-phase chromatographic method is used to monitor the production of DAPG by a strain of Pseudomonas in culture media. The proven higher sensitivity and selectivity of amperometric detection for phenols and catechols are continued here in the analysis of phloroglucinols. Demonstrated selectivity improvements using amperometric detection for the analysis of DAPG in soil samples are however dependent on soil type.