Search Results (3)

We investigated the effectiveness of a multi-sorbent tube (M-Tube) to improve the sampling method for a wide range of odor-causing volatile organic compounds (VOCs) at low concentrations. The M-Tube applied in this study was a fixed tube packed with three adsorbents (Carboxen^®, Carbopack™, and Tenax^®-TA) in series. To verify the efficiency of the M-Tube, a comparative study was conducted against a single tube (S-Tube, Tenax^®-TA). A total of 42 target compounds were selected, including eight different chemical groups: terpenes, hydrocarbons, aldehydes, ketones, alcohols, esters, furans, and alkanes, to verify the effectiveness of the M-Tube. In the laboratory test, response factors, which are the ratios between output signals of gas chromatography by the sorbent-tube sample and the liquid-standard sample, for the M-Tube were higher than those for the S-Tube. The breakthrough volume of the M-Tube was higher than that of the S-Tube, indicating that the M-Tube had a relatively lower method detection limit. In the field application to the sewage treatment plant, 29 compounds were identified, and their concentration ranged from 0.3 to 98 ppbv (above MDL). The detected compounds were considered odor-causing VOCs, and the odor contribution of the compounds could be assessed. We ultimately concluded that comprehensive odor management could be established by determining trace VOCs. Full article

For the first time, volatile hydrocarbons were measured in Croatia, at Mali Lošinj in the period from autumn 2004 to autumn 2005. Mali Lošinj site is conveniently located as a gateway to Croatia for any potential pollution from either Po valley in Italy, or other locations in southern Europe or even Africa. The sampling was performed on multisorbent tubes and then analyzed by thermal desorption gas chromatography with a flame ionization detector. The aim was to determine and estimate the non-methane hydrocarbons in Mali Lošinj, a location with Mediterranean vegetation and species which emit large quantities of volatile organic compounds. Ozone volume fraction and meteorological parameters were also continuously measured, from April to October 2005. Ethane, ethene, ethyne, propane, propene, n-pentane, n-hexane, benzene and toluene were identified in all air samples. Benzene and toluene have been found in ambient air and significant positive correlations between ethyne and ethane, propane and propene indicate emissions from transport. Full article

The health risks of cigarette smoking have been reported to increase continuously, while it is estimated to be responsible for the death toll of more than seven million people globally each year. In an effort to reduce the risk involved in cigarette smoking, nicotine-free inhalators have been developed as smoking-cessation aids. To evaluate the feasibility of nicotine-free inhalators in such respect, we investigated the composition of volatile organic compounds (VOCs) released from the consumption of nicotine-free inhalators of which major components include natural essential oils and traditional Chinese medicinal herbs. Vapor samples from nicotine-free inhalators were generated and collected for analysis using an e-cigarette auto-sampler. The vapor samples were captured onto a multi-bed sorbent tube sampler and a 2,4-dinitrophenylhydrazine (DNPH) cartridge for the quantitative analysis with the aid of thermal desorption-gas chromatography/mass spectrometry and high-performance liquid chromatography, respectively. A total of 29 VOCs were determined in vapor samples at concentrations below 0.2 ppm. Concentrations of (+)-isomenthone and acrolein slightly exceeded the derived no-effect level (DNEL) or sensory irritation level. However, VOCs were below the concentration exposure limit, according to the Occupational Safety and Health Administration (OSHA). According to our study, most of the aroma compounds and VOCs released from nicotine-free inhalator were lower than the DNEL or sensory irritation level. Consequently, it is found that nicotine-free inhalators could be safe to use in reference to toxic guidelines for inhalation exposure. However, if the use of nicotine-free inhalators is over prolonged period, it can also increase the risk of exposure to potentially toxic compounds. Full article