HPLC analysis of nonionic surfactants. Part IV. Polyoxyethylene fatty alcohols

A high performance liquid chromatographic technique (HPLC) was applied to analyze nonionic surfactants of ethylene oxide (EO) adducts. Pattern analyses of EO adducts (ethers), with 2, 10 and 20 average EO units, were carried out using a Lichrosorb SI-60 (10 μm) column (4.6 mm inner dimension (id)×25 cm) under the following conditions: mobile phase-mixture of isopropanol, methanol and n-hexane (gradient): temperature of 50 C: UV detector at 220 nm. No derivatization of the compounds was needed. An improved baseline, in spite of gradient elution, was achieved by adding negligible amounts of anthracene to the eluents. Brominated ethoxylated alcohols, resulting from the addition of bromine to the hydrophobic chain of the ethoxylated fatty alcohol, did not require any changes in the elution conditions.