BUNSEKI KAGAKU Abstracts

Urban air contains various kinds of organic pollutants. Among them, several polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs) are carcinogenic and/or endocrine disrupting. PAHs and NPAHs in the atmosphere mainly originate from imperfect combustion of organic matter, such as petroleum and coal. In this study, total suspended particles (TSP) were collected in three different particulate size fractions by using Andersen low-volume air samplers in Shenyang, Shanghai and Fuzhou, China, in the winter and summer seasons in 2010. Nine PAHs and twelve NPAHs in the extracts from the TSP were analyzed by HPLC with fluorescence detection and chemiluminescence detection, respectively. The mean concentrations of the sums of the nine PAHs and twelve NPAHs were highest in Shenyang and lowest in Fuzhou. In each city, more than 80% of the total PAHs and total NPAHs were found in the fine particulate fraction (＜2.1 μm). All PAHs and NPAHs were clearly higher in the winter than in the summer. Furthermore, the ratio of the molar concentrations of 1-nitropyrene to pyrene ([1-NP]/[Pyr]), which is a suitable indicator to estimate the contribution of diesel-engine vehicles and coal combustion to urban TSP, were smaller in Shenyang in the winter. However, in Shanghai, Fuzhou and Shenyang (summer), the [1-NP]/[Pyr] ratios were close to those of particulates released from diesel-engine automobiles. Our study showed that the major contributors of atmospheric PAHs and NPAHs were diesel-engine vehicles both in the winter and the summer in Shanghai and Fuzhou, and in the summer in Shenyang. However, in the winter in Shenyang, atmospheric PAHs and NPAHs seemed to be affected by the mixture of coal combustion systems, such as coal heating and diesel-engine vehicles.

Ambient particles smaller than 4 μm (PM4) in Kyoto were collected from May 2006 to December 2007, and the concentrations of PM4 mass and PAHs were determined. Such factors as meteorological conditions and air masses transported from China to Japan that affected the atmospheric behavior of particulate PAHs were analyzed. The concentrations of benzo[b]fluoranthene (BbF), Benzo[ghi]perylene (BghiP) and indeno[1,2,3-cd]pyrene (IP) were highest among PAHs contained in atmospheric particulates. Atmospheric concentrations of PAHs were high in the winter and low in the summer due to the volatilization and photodegradation of PAHs in the summer. The contents of 6-ring PAHs in PM4 were larger than those of 4-ring and 5-ring PAHs. This is because of the tendency of the 6-ring PAHs to have lower vapor pressures than 4-ring and 5-ring PAHs. The concentrations of PAHs correlated with the NO₂ concentrations. These results indicate that the source of ambient PAHs may be anthropogenic emissions from automobiles. The high concentrations of atmospheric PAHs during continental yellow sand, “Kosa”, and the cold season may be attributed to the long transport of air pollutants from China to Japan based on backward trajectory analysis.

Odor perception is the only one of our five senses that reaches beyond time and space. In ancient times odor was used more often in order to discriminate, foreknow and avoid existing danger. However, the modern lifestyle has taken away the original sharpness of our five senses. In this review work, we surveyed the nature and explained the usefulness of the active odor recognition of fire by odor in Melanophila. Odor perception enables creatures to sense the outer world, for example, sniffing the future world of emerging danger and the past world by tracking any trace of bait for their survival. We examined the burn smell of wood as an example of present odor detection. We found that the decomposition products of cellulose and perfumes of the wood are generated when wood is heated and pyrolized, and that levoglucosan is the signal molecule from fire and burning wood. Because of a lack of fossil-fuel energy and carbon dioxide emissions problems, an energy revolution has taken place, and new energy sources, like hydrogen and dimethylether (DME), will be introduced into our life. In this era, no smog and less carbon dioxide is released by fuel, and with less odor. We cannot sniff soldering smell in our daily life, and thus need some new sensor to monitor the combustion system in order to guard our life in such an era. Here, we introduce a semiconductor odor sensor and soft ionization mass spectrometry as a “smart nose”. The odor molecules are encapsulated in the graphite microcapsule structure of soot, which reserves them without release. Recent scientific analysis on soot provides tools for fire research in order to distinguish fire from arson. Furthermore, in our group, hydrogen emission experiments were conducted; the hydrogen concentration was monitored by a new type ion sensor for hydrogen. The real-time performance of this Hydrogen sensor is introduced.

The distribution behavior in ionic liquid/water biphasic systems of substituted benzenes, phenols, and phenolate anions was investigated in detail. The ionic liquids used were five common hydrophobic ones of 1-butyl-3-methylimidazolium, 1-methyl-3-octylimidazolium, and 1-butyl-1-methylpyrrolidinium cations. For electrically neutral solutes, the partition coefficients in the ionic liquid/water system are insensitive to the kind of the ionic liquid, and show a correlation with those in the 1-octanol/water system. From analysis based on the regular solution theory, the similarity in extraction ability between the ionic liquids and 1-octanol was attributed to the closeness of the solubility parameters of these solvents. The interaction energies between the polar substituents and the ionic liquids were also evaluated. It was revealed that the ionic liquids act as both Lewis acids and bases, like 1-octanol; however, they are weaker in basicity, but stronger in acidity, than 1-octanol. The ionic liquids can extract phenolate ions, and the extraction ability is governed by the hydrophobicity and hydrophilicity of the component cations and anions, respectively. The extraction of phenolate ions includes both the mechanisms of ion-pair extraction and ion exchange with the component ions. The model of the extraction equilibrium of anions with ionic liquids was established, and a regular relationship between the anion distribution ratio and the ionic liquid solubility product in water was found.

The preconcentration methods are effective approaches to enhance the sensitivity and resolution of various analytical instruments without any mechanical improvement of the machine and the relative detectors. In this review, we focus on unique high-powered preconcentrations and separation systems based on the phase separation that arise a secondary-liquid phase from homogeneous solution by chemical reaction; (it has been dubbed as homogeneous liquid-liquid extraction (HoLLE)). Particularly, HoLLE has been used as linker techniques to combine between various preconcentrations and analytical instruments. Integration of the preconcentrations has been introduced as a cascade type in the preconcentration series. By adding the chemical approach to the systems, it can be applied to not only powerful condensation, but also be a selective separation and isolation technique.

The elution behaviors of styrene-methyl methacrylate [P(St-MMA)] random copolymer and block copolymer with different compositions were characterized by eluent gradient high-performance liquid chromatography. P(St-MMA) samples were eluted depending on the styrene content with a linear gradient from 100% acetonitrile to 100% THF. The relation between the styrene content in P(St-MMA) and the composition of THF in the eluent at the time of P(St-MMA) eluting indicated a good correlation; the composition of THF in the eluent at the time of a random copolymer eluting differed from that at the time of the block copolymer of the same styrene content. Two random and block copolymer samples were characterized based on the molecular-weight dependence of the styrene content by 2D-HPLC.

A high-speed HPLC analysis for fermentation product A in the purification process was evaluated by using four kinds of commercially available core shell columns (75 × 4.6 mm i.d.; particle size, 2.6〜2.7 μm) instead of a general porous particle column (Honenpak column, 75 × 4.6 mm i.d.; particle size, 3 μm). These core shell columns (Ascentis^®Express C18, HALO C18, SunShell C18, Kinetex) showed similar performances to the porous particle column (Honenpack) in terms of the theoretical plate, asymmetry factor and pump pressure under almost the same operation conditions. Especially, SunShell C18 exhibited the highest theoretical plate among them, which made it possible to shorten the analysis time (the retention time of compound A was 6.6 minutes for SunShell C18 and 14.6 minutes for Honenpack, respectively). Our results confirmed that core shell columns are available to reduce the total analysis time for process tests that usually require a rapid response to proceed the process.

Time-resolved helium microwave-induced plasma atomic emission spectrometry (He MIP AES) was developed for the detection of fine-particles in a suspension. The plasma was generated by 2.45 GHz microwave power (— 1 kW) with the Okamoto cavity of the surface wave mode at atmospheric pressure. Sample particles of Ag (median dia. 368, 518, 833, 1304 nm), Al₂O₃ (409 nm), BaTiO₃ (2062 nm) and Fly-Ash (BCR-038, 5413 nm, composition: As, Cl, Co, Cr, Cu, F, Fe, Mn, Na, Pb, Zn etc.) were used. A suspension including one of these particles was nebulized, and the generated droplets included or adhered to the particle were introduced into the center of the annular He-MIP through an inner tube of a torch along with the carrier gas (Ar). A time-resolved atomic emission spectrometry was studied for particulate composition analysis of each droplet. Preliminary experimental data are presented. The time-resolved He-MIP AES could be detected with sufficient sensitivity.

The applicability of metal oxide as a selective extractant for ionic compounds was investigated to establish an easy and selective determination method using ion chromatography coupled with conductivity detection. The extraction properties of zirconia and titania for glyphosate (N-(phosphonomethyl)glycine, GLYP) as an analyte were evaluated. Although it has been recognized that both zirconia and titania have high affinity for phosphate compounds, the leakage of GLYP from a solid-phase extraction cartridge packed with the titania used in this study was observed. On the other hand, zirconia could perform an effective extraction of GLYP with high retention ability. Also, a solid-phase extraction cartridge packed with 35 mg of the zirconia was able to certainly entrap GLYP in spite of a sample load of 250 mL. GLYP entrapped on the zirconia could be eluted with 2 mL of 0.4 M sodium hydroxide as an eluent. GLYP in the effluent could be sensitively detected by ion chromatography with conductometric detection using neutralization employing a suppressor module. The proposed method was applied to the determination of GLYP in urban river water samples. The limit of quantification was around 0.001 mg L⁻¹ for GLYP.