Ambient ionization processes are becoming more widely used for the measurement of atmospherically relevant particles and gases. We report here ambient ionization mass spectra utilizing a commercial tincture of iodine and a piezoelectric discharge gun (PDG) to generate the ionizing reagents. Analytes include Cl-2, Br-2, HNO3, the C-1-C-9 series of saturated monocarboxylic acids, benzoic acid, 2,2-dimethyl-propanoic acid, 9-decenoic acid, and trichloroacetic acid. While Cl-2 and Br-2 form the [M + I](-) odide adducts, HNO3 and the organic acids show unexpected peaks corresponding to [2M - 2H + I](-). For HNO3, the new ion formed is interpreted as the [NO3-center dot center dot center dot IONO2] complex, where IONO2 is likely formed upon reaction of HOI with gaseous NO3-. Similarly, for the organic acids, the [2M - 2H + I](-) peaks are interpreted as [RC(O)O-center dot center dot center dot IOC(O)R] complexes formed by association of RC(O)O- with acyl hypoiodites [RC(O)OI]. It is proposed that the association of (1) Cl-2 and Br-2 with I-, (2) IONO2 with NO3- ions, and (3) RC(O)OI with carboxylate ions occurs via non-covalent halogen bonding. The results suggest the possibility that halogen bonding may play a role in chemical transformations in the atmosphere, particularly in particles where concentrations of iodinated species may be significant.

Volatile organic compounds emitted from a several decade series of bound periodicals (1859–1939) printed on ground wood paper, as well as historical books dating from the 1500s to early 1800s made from cotton/linen rag, were studied using an improved headspace SPME/GC–MS method. The headspace over the naturally aging books, stored upright in glass chambers, was monitored over a 24-h period, enabling the identification of a wide range of organic compounds emanating from the whole of the book. The detection of particular straight chain aldehydes, as well as characteristic alcohols, alkenes and ketones is correlated with oxidative degradation of the C18 fatty acid constituency of paper. The relative importance of hydrolytic and oxidative chemistry involved in paper aging in books published between 1560 and 1939 was examined by comparing the relative abundances of furfural (FUR) a known cellulose hydrolysis product, and straight chain aldehydes (SCA) produced from the oxidation of fatty acids in paper. The relative abundance of furfural is shown to increase across the 379-year publication time span. A comparison of relative SCA peak areas across the series of books examined reveals that SCA emission is more important in the cotton/linen rag books than in the ground wood books.

Discovery of the fuel additive methyl tert-butyl ether (MTBE) in groundwater, surface water, and stormwater has prompted studies of its sources, transport and fate. More limited data, however, is available on the extent of contamination of coastal waters, as well as the persistence of MTBE in the marine environment. We apply here the combination of solid phase microextraction and gas chromatography–mass spectrometry to the detection of sub-to-low μg/l concentrations of MTBE in seawater samples. Analysis of samples collected at the Marina del Rey harbor, a shallow recreational harbor near Los Angeles, CA, show MTBE contamination in the low μg/l level. MTBE measurements were made at different depths, from the surface to the bottom, at five sites within the harbor during months showing no measurable precipitation. The highest concentration of MTBE (18 μg/l) was found at the boat launching ramp, and the lowest (0.2 μg/l) near the harbor entrance, approximately 2.3 km from the ramp. The levels of MTBE measured, as well as their variation over the study period, are fully consistent with recreational boating as the primary source of contamination. No evidence for MTBE contamination from the adjacent stormwater control channel was noted.

In many urban areas, automobile transportation accounts for the majority of smog-forming emissions, and air pollution control legislation continues to spur the research and development of lower-emission automobiles. We describe here a laboratory project, suitable for the general chemistry or physical chemistry laboratory, which uses Fourier transform infrared (FTIR) spectroscopy for the analysis of automobile exhaust. Using this method, products of both complete and incomplete combustion of gasoline are identified in exhaust under various vehicle-operating conditions. By quantifying the level of carbon monoxide in exhaust from automobiles manufactured over a sixty-model-year range, students are able to understand the factors that reduce the emission of incomplete combustion products.

We present here a discovery-based laboratory project that introduces elementary quantum mechanical concepts using the spectral distributions of natural and artificial light sources. The measured emission spectra of sunlight and interior/exterior lighting are explained using the electromagnetic spectrum, the phenomenon of blackbody radiation, and the quantization of light. This 4–5 week experiment is appropriate for the general chemistry laboratory or can be expanded for use in upper-division chemistry laboratories, and it uses modern spectroradiometric equipment that is readily available and increasingly used in the physical and biological sciences.

In many urban areas, automobile transportation accounts for the majority of smog-forming emissions, and air pollution control legislation continues to spur the research and development of lower-emission automobiles. We describe here a laboratory project, suitable for the general chemistry or physical chemistry laboratory, which uses Fourier transform infrared (FTIR) spectroscopy for the analysis of automobile exhaust. Using this method, products of both complete and incomplete combustion of gasoline are identified in exhaust under various vehicle-operating conditions. By quantifying the level of carbon monoxide in exhaust from automobiles manufactured over a sixty-model-year range, students are able to understand the factors that reduce the emission of incomplete combustion products.