Solvent bar micro-extraction (SBME) based determination of PAHs in seawater samples

- Priority PAHs from seawater were pre-concentrated by SBME.
- SBME allows the measurement of PAHs in the level of ng L− 1 in seawater.
- Pre-concentration of PAHs is dependent on their molar mass.

Measuring the impact of PAHs in seawater samples is often difficult due to the low concentrations in which they appear and the complexity of the sample matrix. Traditional methods for sample preparation such as liquid-liquid extraction and solid phase extraction require the use of excessive amounts of solvents and reagents, and sample handling. In this work, hollow fiber liquid phase micro-extraction (HFLPME), in the configuration of solvent bar micro-extraction (SBME), was proposed as an environmentally friendly and more effective tool, for the extraction of the 16 priority PAHs from seawater samples. Extraction was conducted using hexane as a solvent. Enrichment factors from 45 to 163 were obtained after 60 min at a stirring rate of 500 rpm in the sample. Moreover, a negative linear relationship was observed between the enrichment factor and the molecular weight of the PAHs. Under optimized conditions, the limits of detection were in the range from 0.21 to 0.82 ng L− 1, the method showed a linear response up to 500 μg L− 1, and the average relative standard deviation for seawater samples spiked with 5 ng L− 1 was 11.6%. After calibration, the SBME was applied to extract PAHs in seawater samples from the Bay of Cadiz (SW Spain), showing an average recovery of 99%. In conclusion, the SBME is an environmentally friendly, one-step alternative for sample preparation in the determination of PAHs in seawater samples.

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