Fingerprinting of Fatty Alcohols in Environment Samples

Introduction

Fatty alcohols (Figure 1) occur in the environment from a range of natural and anthropogenic sources. Fatty alcohols are used in cosmetic and detergent formulations usually as sulphates or polyethoxylates. They are disposed of ‘down the drain’ and undergo degradation during sewage treatment and these degradation products may eventually make their way to the marine environment. Fatty alcohols are also produced naturally by a wide range of organisms. These compounds may be transported via several routes to the sediments of the marine environment. Some free fatty alcohols have been identified as potential pollutants (Aliphatic Alcohols [C6-22] SIAR, 2006) as they typically have a greater aquatic toxicity (LC50 <1 mg.L-1) than most of the ester and ether bound compounds. Comparison of fatty alcohol concentrations from waste water treatment plant (WWTP) effluent monitoring studies of alcohol ethoxylates (AE) (Eadsforth et al., (2006), Morrall et al., (2006)) with a laboratory continuous activated sludge study with AE (Wind et al., (2006)) has indicated that only a small fraction of fatty alcohols in WWTP effluents originates from AE entering the WWTP. To assess the risk associated with the use of fatty alcohol based surfactants used in detergents, the sources of the free fatty alcohols and the relative contribution of surfactants need to be determined. Due to the multiplicity of potential sources of fatty alcohols, further detailed molecular investigations are needed to determine the origin of various free fatty alcohols from natural and synthetic sources.