Assessment of perfluoroalkyl substances levels in tap and bottled water samples from Turkey.

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) draw considerable attention for their potential toxic effects in humans and environment. Drinking water is accepted as one of the major exposure pathways for PFASs. In this study, we measured concentrations of 10 perfluoroalkyl substances in 94 tap water samples collected in two different sampling periods (August 2017 and February 2018) from 33 provinces of Turkey, as well as in 26 different brands of plastic and glass-bottled water samples sold in supermarkets in Turkey. Perfluorohexanoic acid (PFHxA), perfluorobutane sulfonate (PFBS) and perfluoropentanoic acid (PFPeA) were the most frequently detected PFASs in the samples of tap waters. The maximum concentrations in tap waters were measured as 2.90, 2.37, 2.18, 2.04, and 1.93 ng/L, for PFHxA, perfluorooctanoic acid (PFOA), perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS), and perfluorobutanoic acid (PFBA), respectively. The most abundant perfluorinated chemical in tap water samples was PFBA with 17%, followed by PFOS (13%), PFBS (12%), perfluoroheptanoic acid (PFHpA) (11%), PFHxA (11%), and PFOA (11%). The total PFASs concentration in tap water ranged from 0.08 to 11.27 ng/L. As regards bottled waters, the concentrations of PFASs were generally lower than those in tap water samples. These results revealed that tap water samples in Turkey might be considered generally safe based on the established guidelines around the world. However, due to their persistence and potential to accumulate and reach higher concentrations in the environment, careful monitoring of PFASs in all types of water is critical.

Rapid extraction and reverse phase-liquid chromatographic separation of mercury(II) and methylmercury in fish samples with inductively coupled plasma mass spectrometric detection applying oxygen addition into plasma.

A simple and sensitive procedure was developed for extraction and speciation of mercury in fish. Species separation was accomplished with reverse phase-high performance liquid chromatography (HPLC) hyphenated to inductively coupled plasma mass spectrometry (ICP-MS). Oxygen addition into plasma allowed use of organic-rich mobile phase, achieving species separation in 4 min. Mercury species extraction was achieved by microwave exposure for 2 min at mild conditions (60°C, pH 2.0), avoiding necessity of neutralizing sample prior to injection in HPLC, and reducing number of sample preparation steps, analytical source of errors and inter conversion of species. Limit of detection for entire procedure was found to be 0.2 and 0.1 ng g(-1) for mercuric ion and methylmercury, respectively. The method was applied to certified reference materials (TORT-2 and DORM-2) and commercialized fish samples (Mullus barbatus, Sparus aurata, Trachurus mediterraneus, Mugil soiuy, Dicentrarchus labrax, and Pomatomus saltatrix) from Black Sea.