Evaluation of two extraction methods for determination of nonylphenol contaminant in sediment

Environmental pollution levels have been more sensitively assessed as a result of the ongoing, unchecked release of contaminants into aquatic systems in emerging countries like Indonesia. Sediment of Citarum river was collected and analysed for 4-Nonylphenol that has been shown to possess endocrine-disrupting properties. This study evaluated two extraction methods using liquid-liquid extraction (LLE) and solid phase extraction (SPE) for determination of nonylphenol in sediment to find the best extraction method. The liquid-liquid extraction was performed using dichloromethane: hexane (2: 1). The SPE method is combination of small amount of liquid-liquid extraction using methanol: water (70: 30) followed by solid phase extraction using C-18 cartridge and methanol-acetonitrile as an eluent. The measurement was performed using gas chromatography with HP-5 column and flame ionization detector. The linearity, precision, accuracy, limit of detection and limit of quantification were evaluated. Nonylphenol determination was linear at the concentration range of 0.1-10 µg/mL. The precision of 2.26-2.34% was obtained for both methods. The recovery of the fortified sample (0.05 and 0.1 µg-NP/mL) were 76.28-80.52 % for the LLE method and 96.24-104.78% for the SPE method. Limits of detection and quantification were 0.2 and 0.4 µg/mL for the LLE method. Limits of detection and quantification for the SPE method were 0.05 and 0.2 µg/mL. Based on the high recovery and low limits of detection and quantification, the extraction method using solid phase extraction is better than liquid-liquid extraction and it can be used for rapid and accurate quantification of nonylphenol.