Analysis Of Alkylphenol Ethoxylates And Their Metabolites In The Aquatic Environment Using Liquid Chromatography Tandem Mass Spectrometry

Alkylphenol ethoxylates (APEOs) have been widely used as part of industrial processes and as detergents in household. Nonylphenol polyethoxylates(NPEOs) account for the 80% for the APEOs products, while the remaining 20% is basically octylphenol polyethoxylates(OPEOs). In the aquatic environment and sewage treatment, the APEOs degrade to short chain APEOs, alkylphenol carboxylic acids(APEC) and alkylphenols(AP). Different investigations have reported that APEO metabolites are more toxic than their parent compounds and have the ability to mimic natural hormones by interacting with the estrogen receptor.A quantitative method is described for the analysis of the alkylphenol ethoxylates and their metabolites in surface water and drinking water using reversed-phase high-performance liquid chromatography with electrospray tandem mass. Nonyl- and octylphenols, nonyl-and octylphenol mono- and diethoxylates, nonyl- and octylphenoxy acetic acid were concentrated from water samples using a C₁₈ solid-phase extraction procedure. 5.00mL dichloromethane and 5.00mL ethyl acetate were used to elute APEOs and their metabolites. Quantitative LC/MS/MS was performed in the negative ion mode for nonyl- and octylphenol, nonyl- and octylphenoxy acetic acid and in the positive ion mode for nonyl- and octylphenol mono-, diethoxylates. Recoveries for tap water analyses ranged between 84.3%～122%, and surface water analyses between 82.0%～114%. Detection limits for APEO and metabolites were between 0.1～19ng/L. This is better than previously reported methods. Individual APEO metabolite concentrations of 4.05～9.45ng/L and 4.55～92.8ng/L are reported for surface water and drinking water from Huaihe area.