Rapid analysis of 4-nonylphenol by solid phase microextraction in water samples.

Alquilphenols are considered to be endocrine disruptors and are mainly found as 4-nonylphenol (4-NP) in ecosystems. A chromatographic analytical method was developed using solid phase microextraction (SPME) combined with gas chromatography-mass spectrometry (GC-MS) for the extraction and quantification of 4-NP in sources of water in Mexico to establish environmental concentrations. A derivatization process with N-Methyl-bis(trifluoroacetamide) (MBTFA) was carried out in order to increase sensitivity in the method. The method was validated with a correlation coefficient above 0.99, and a limit of detection and quantification of 0.01 μg L and 0.15 μg L respectively, which were determined by a linear curve at low 4-NP concentrations. After demonstrating the feasibility of the method, an analysis in water samples was performed. Eighty-three percent of samples had detectable concentrations of 4-NP with a maximum concentration of 12.61 μg L, 12.2 μg L and 6.08 μg L in recreational water, wastewater discharges and drinking water respectively. Sixty-five percent of the samples presented concentrations above the limit established by the European Union (2 μg L) and 17% above the limit by the Environmental Protection Agency (6.6 μg L). Although the number of samples is not representative for the assessment of the real-world scenario, our data presents a general overview of the exposure levels and possible environmental and health risks. Continuous monitoring and regulation of this pollutant in Mexico is important in order to prevent exposure and thus, ecological and adverse health effects.