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The gas chromatography/mass spectrometric assay method was developed for the determination of 13 non-steroidal anti-inflammatory drugs (NSAIDs) in river water. Extraction was achieved by a liquid-phase extraction procedure using methylene chloride. The extract was reacted for 30 min at 80°C based on the formation of methyl ester with 1.0 M HCl in methanol and extraction of the derivative with ethyl acetate, which was then measured by gas chromatography-mass spectrometry. The limit of quantification of NSAIDs was 1.0-60 ng/L and the calibration curve showed linearity being greater than r=0.997. The method was used to analyze ten river water samples from various regions in Korea. Diclofenac, indoprofen, ketoprofen and loxoprofen were detected at concentration of up to 1.29 μg/L in river water. The developed method may prove valuable for use in the national monitoring project of NSAIDs in surface water.

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Electronic cigarettes (E-cigarettes) are devices that are refilled with replacement liquids, which normally contain propylene glycol, nicotine and the desired flavor blend. Many consumers suspect that hazardous substances are present in addition to nicotine content. In this study, eight contaminated compounds in 105 replacement liquids from 11 types of E-cigarettes sold in the Republic of Korea were identified and quantified by gas chromatography-mass spectrometry. Diethyl phthalate and diethylhexyl phthalate were detected in concentration ranges of 0.01-1745.20 mg/L (47.6% detection frequency) and 0.06-81.89 mg/L (79.1% detection frequency) in the replacement liquids. Triethylene glycol, tetraethylene glycol and pentaethylene glycol were quantified in concentration ranges of 0.1-19.3 mg/L (10.5% detection frequency), 0.1-30.1 mg/L (12.4% detection frequency) and 0.1-24.9 mg/L (6.7% detection frequency) in the same samples. cis-3-Hexene-1-ol, methyl cinnamate and dodecane were quantified in concentration ranges of 0.03-3267.46 mg/L (70.5% detection frequency), 4.41-637.54 mg/L (6.7% detection frequency) and 0.01-639.96 mg/L (47.6% detection frequency) in the samples.