Survey of bottled drinking water sold in Canada. Part 2. Selected volatile organic compounds

Selected volatile organic compound (VOC) contaminants were determined in 182 samples of retail bottled waters purchased in Canada. Samples included spring water (86) packaged in containers of polyethylene or in smaller containers of transparent plastic or glass, mineral water (61) packaged only in transparent plastic or glass, and miscellaneous bottled waters (35). Analyses were performed by 3 laboratories, each using headspace sampling and capillary gas chromatography with either mass spectrometric (1 laboratory) or flame ionization detection with mass spectrometric confirmation, if required (2 laboratories). Benzene, the contaminant of primary interest, was detected in only 1 of the 182 samples at 2 micrograms/kg. Other VOC contaminants detected (number of positive samples, average, and range of positives in micrograms/kg) included toluene (20, 6.92, 0.5-63), cyclohexane (23, 39.2, 3-108), chloroform (12, 25.8, 3.7-70), and dichloromethane (4, 59, 22-97). Cyclohexane was found in the plastic and as a migrant from the plastic in 20 samples of spring water, but it was found in only 1 of 61 mineral water samples analyzed at only 3 micrograms/kg. Chloroform was found almost exclusively in samples that could have been obtained from public water supplies. It was not found in mineral water samples, but it was found in 1 spring water sample at 3.76 micrograms/kg. The source of the toluene contamination was not known. Other VOCs detected include ethanol and limonene, associated with added flavoring; pentane, as a migrant from a foamed polystyrene cap liner; and 1,1,2,2-tetrachloroethylene in a sample of demineralized water.

ortho-Diquaternary aromatic compounds. II. Synthesis and spectral properties of β,β′-dihydroxy-2,3-di-t-butylnaphthalene and related crowded aromatics

Cyclialkylation of naphthalene with 2,2,5,5-tetramethyltetrahydrofuranone yielded 2-keto-1,1,4,4-tetramethyl-1,2,3,4-tetrahydroanthracene (1). Selenium dioxide oxidation of 1 yielded the corresponding diketone (3) and periodate cleavage of 3 yielded 2,3-naphthalene-diisobutyric acid (4). Hydride reduction of the dimethyl ester (6) of 4 yielded the diol, β,β′-dihydroxy-2,3-di-t-butylnaphthalene (7). The relative chemical shifts of aromatic protons of 1,2,4,5-tetraalkylbenzenes containing gem dimethyls are rationalized in terms of compression effects exerted by the bulky ortho groups. Nuclear magnetic resonance and ultraviolet spectral results for the ortho di-t-butyl aromatic derivatives 4, 6, and 7 are compared to the model cyclic compounds 1 and anhydride (5) of 4 in terms of the strain caused by bond angle deformations in the side chains.