Determination of phenols and phenates in disinfectant formulations by liquid chromatography with UV detection: collaborative study.
Fourteen collaborating laboratories assayed o-phenylphenol (OPP), p-t-amylphenol (PTAP), and o-benzyl-p-chlorophenol (OBPCP) in formulated products, both ready-to-use and concentrates, by RP-HPLC. The actives in the samples ranged from 0.03 to 11% OPP, 0.06 to 4% PTAP, and 0.07 to 10% OBPCP either in free forms or as salts. Seven blind duplicates were analyzed. The samples were diluted/extracted with acidified methanol, filtered, and analyzed by LC on a C18 column using gradient elution and UV detection at 285 nm. The concentration of the active ingredients was calculated from a standard curve. Each laboratory weighed each test sample twice within a single analytical run. The data were analyzed using all 14 laboratory results, with appropriate statistical tests to detect outliers. The repeatability RSDs ranged from 0.98 to 3.40% for the free phenols, and 1.26 to 2.51% for the salts. The reproducibility RSDs ranged from 5.31 to 7.80% for the free phenols, and 5.50 to 8.67% for the salts. The HorRat ranged from 0.86 to 2.17 for the free phenols, and 1.54 to 2.72 for the salts.
Maryland Department of Agriculture, State Chemist Section, 50 Harry S. Truman Pkwy, Annapolis, MD 21401, USA. PhilliTD@mda.state.md.us
Tom
T
Phillips
Adrian
A
Burns
D002853:Chromatography, Liquid / Q000379:methods*; D004202:Disinfectants / Q000494:pharmacology*; D007753:Laboratories; D010636:Phenols / Q000737:chemistry*; D014466:Ultraviolet Rays
D004202:Disinfectants; D010636:Phenols