Are other phenols better extractants?
Since hydrogen bonding is important, more acidic phenols (e.g. chlorophenol) are likely better extractants, though phenol itself is so efficient that improvements may not be of practical benefit. Hydrophobicity also influences extraction; it is not clear how these forces balance in practice. Improving nucleic acid and protein extraction pH and salt concentration are the two easily controllable variables. Salt at acid pH facilitates protein extraction , but higher pH suppresses extraction of organic acids. LiCl is a convenient salt because it’s soluble in acetone and alcohols. General comment on the scientific status of phenol extraction Phenol has been through two heydays, firstly the turn of the century as a disinfectant and secondly in the ’50s as a nucleic acid extractant. One most commonly uses recipes and works with complex systems. Phenol extraction of model compounds has been ignored. Phenol extraction is unfortunately more art than science.
