Innovative analytical method for the determination of underivatized tributyltin and pentachlorophenol in seawater by gas chromatography-triple quadrupole mass spectrometry

•GC-MS/MS applied to the analysis of tributyltin and pentachlorophenol in seawater.•MeOH/MeOTMS mixture allowed gas chromatographic separation of underivatized tributyltin and pentachlorophenol.•Method performance in compliance with the strict EU requirements.

Tributyltin (TBT) and pentachlorophenol (PCP) are listed as priority substances that warrant monitoring in the European Water Framework Directive (WFD 2000/60/CE), since TBT and PCP were identified as environmental endocrine disruptors and exhibit considerable toxicity toward both aquatic organisms and mammals even at very low levels.This paper shows a novel approach to analyze underivatized tributyltin (TBT) and pentachlorophenol (PCP) in seawater based on capillary gas chromatography-triple quadrupole mass spectrometry. The optimized extraction method for TBT an PCP in water involved liquid-liquid microextraction with toluene. The reduced extract was added with a solvent mix, composed of methanol and trimethylsilyl derivatives of methanol (MeOTMS), that allowed good chromatographic resolution of underivatized TBT and PCP, interacting as a lubricant along the glass liner during the injection phase.The proposed method showed good linearity and repeatability (RSD%<20% at 0.05 ng L−1 for TBT and 0.2 μg L−1 for PCP). The overall recoveries were 74% and 106% for TBT and PCP, respectively. Very low quantification limits that met the strict statutory and regulatory demands were achieved: 0.002 ng L−1 for TBT and 0.050 μg L−1 for PCP.

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