Development and validation of a method using on-line solid-phase extraction and liquid chromatography with ultraviolet detection for the determination of bisphenol A, octylphenol, and nonylphenol in groundwater

Alkylphenols are non biodegradable metabolites arising from various pathway s of aerobic and anaerobic degradation of the nonionic surfactants alkylphe nol ethoxylates. A method based on the use of on-line solid-phase extractio n (SPE) and liquid chromatography (LC) with UV detection was developed to d etermine bisphenol A, octylphenol, and nonylphenol at trace levels in water . The on-line coupled SPE procedure automatically enables an approximately 300-fold preconcentration of analytes, which can be further enhanced by an increase in applied sample volume. By using C-18 cartridges, recoveries of > 90% were obtained for all the analytes. A validation procedure was carrie d out with a groundwater sample to ensure the quality of the results; perfo rmance criteria such as detection limits (LODs), quantitation limits (LOQs) , linearity, and precision were evaluated. LODs and LOQS in the range of 0. 17-0.36 and 0.35-1.88 mug/L, respectively, were found; for all the analytes , linearity was established over 2 orders of magnitude (r(2) > 0.997, n = 5 4). The intraday repeatability values expressed as relative standard deviat ions were <5.3%; a nested analysis of variance was performed to verify the influence of 3 different factors, i.e., different days, extraction procedur e, and LC replicate injection, on data precision.