Determination of dodecanol and ethoxylated fatty alcohols from environmental samples using diatomaceous earth as a green sorbent for solid-phase extraction.

This study describes the use of diatomaceous earth during solid-phase extraction as an efficient sorbent for separation and concentration of dodecanol and ethoxylated dodecanol containing 1-9 ethoxyl groups. The efficiency of different eluents was evaluated for model samples which allowed to select methanol and chloroform for tests with river water samples. During model experiments, it was observed that the recovery rates of specific compounds in the studied mixture were influenced by the character of the solvent used for desorption. Hydrophobic compounds, such as dodecanol and ethoxylated dodecanol with 1-3 ethoxyl groups, were eluted by chloroform with 100% efficiency. In case of the remaining compounds, which were more hydrophilic, a 97% recovery rate was achieved during elution with methanol. Such dependencies were not observed in case of river water samples, as the results obtained for both studied sorbent-eluent systems were comparable. In both variants the recovery of dodecanol and ethoxylated dodecanol containing 1-9 ethoxyl groups ranged from 33 to 99%.