Determination of alkylphenol ethoxylates (APEs) and alkylphenols (APs) in water and sediment from River Benue, North Central Nigeria

Abstract

In this study, alkylphenol ethoxylates (APEs) including their alkylphenol (AP) derivatives; octylphenol ethoxylate (OPE), nonylphenol ethoxylate (mono-NPE), nonylphenol di-ethoxylates isomers (di-NPE1 and di-NPE2), octylphenol penta ethoxylates (OPPE), nonylphenol penta ethoxylates isomers (NPPE1 and NPPE2), tert-butylphenol (t-BP), tert-octylphenol (t-OP), tert-nonylphenol (t-NP) and octylphenol (OP) were determined in water and sediment samples from River Benue, in the Makurdi Metropolitan Area, North Central Nigeria using gas chromatogragh – mass spectrometer. APEs are of significant research interest due to their extended use in several consumer and personal-care products couple with their ability to mimic natural hormones and disrupt the endocrine system. The samples were collected from the River, bi-monthly, for one year across dry and wet seasons.  Most of the compounds considered were found to be present in both water and sediment. The total concentrations of APEs (Σ8APEs) in water ranged from 1.56 – 45.92 ngL-1 during dry season and from 0.76 – 27.49 ngL-1 during wet season while in sediment, during dry and wet seasons, it ranged from 15.15 – 45.26 ngg-1 and 2.02 – 27.12 ngg-1 respectively. The results also showed the total concentration of APs (Σ5APs) in water in the range of 0.07 – 2.12 ngL-1 and 0.00 – 2.11 ngL-1 during the dry and wet seasons respectively. In sediment, the Σ5APs ranged from 0.67 – 1.75 ngg-1 during dry season and 0.10 – 2.90 ngg-1 during the wet season. It was concluded that the result of this study can provide useful reference for further studies on APs and APEs pollution and risk assessment in the river.Keywords: Gas chromatograph – mass spectrometer, alkylphenol ethoxylates, alkylphenol, sediment, river water