Determination of phenolic disinfectant agents in commercial formulations by liquid chromatography

Using liquid chromatography (LC), a convenient and versatile method was developed for the assay of disinfectant products containing the commonly used phenolic agents, alone or in combination, including phenol, 2-phenylphenol, 4-t-amylphenol, 4-chloro-3,5-dimethylphenol (PCMX), 2-benzyl-4-chlorophenol, and triclosan. The procedure involves a simple dilution or dissolution of the product aliquot or portion followed by membrane filtration and LC. The method was applied to 19 different products representing 17 manufacturers and containing from one to 4 phenolic agents. Chromatography was performed using a Zorbax SB-C18 column, acetonitrile-0.05M KH2PO4 (55 + 45, v/v) pH 3.00, as mobile phase and UV detection at 280 nm. The intralaboratory precision of the product assays ranged form 0.34-5.35% (n = 5) and recoveries via fortification varied from 96.1-103.8%. The limits of quantitation (LOQ) and detection (LOD) ranged from 5.58 x 10(-5) to 2.50 x 10(-4) mg/mL and from 1.76 x 10(-5) to 0.67 x 10(-4) mg/mL, respectively, for the 6 analytes. The response for all analytes was observed to be linear for at least a 50-fold range in concentration (0.001-0.05 mg/mL). The proposed method provides an efficient means for the isolation and quantitation of these phenolic compounds.