Selective HPLC analysis of n-alkyl hydroperoxides up to C18H38O2

A series of n-alkyl hydroperoxides are separated by HPLC and detected by their postcolumn reaction with horseradish peroxidase and p-hydroxyphenylacetic acid (HPAA) to yield a fluorescent product; several secondary and tertiary hydroperoxides, some 1-hydroxyalkyl hydroperoxides, and a few branched hydroperoxides are also examined, n-Alkyl hydroperoxides up to at least C-18 react with the enzyme with only minimally reduced efficiency at greater alkyl chain length, The effects of the column, the eluent, and the pH of the sample reaching the detector are described, The detection limit with gradient elution ranges from 0.4 mu mol L-1 for n-hexyl hydroperoxide to 1 mu mol L-1 for n-octadecyl hydroperoxide.