Compound class specific radiocarbon analysis (CCSRA) was performed for polycyclic aromatic hydrocarbons (PAHs) associated with airborne particulate matter (APM) with diameter <10 microm (PM10) and <1.1 microm (PM1.1) collected from a residential area of suburban Tokyo, Japan, and seasonal and particle-size radiocarbon variations were investigated. Source diagnostic isomer pair ratios indicated mixed contributions from petroleum combustion and from biomass and coal combustion to the PAHs in APM. The delta14C- PAHs in APM, ranging from -787 to -514 per thousand, indicated dominance of fossil fuel combustion. The delta14C of 5-6 rings (HMW) PAHs were higher than the 3-4 rings (LMW) species in both PM10 and PM1.1 samples. The delta14C of HMW-PAHs indicated greater biomass-burning contributions in summer than in winter and no apparent particle-size variation. Conversely, the delta14C of LMW species showed a greater contribution from fossil sources in summer and in larger particles (PM10). This finding could be tentatively attributed to the recondensation of fossil-PAHs vaporized from petroleum sources. A 14C isotopic mass balance approach estimated that biomass burning contributes 17-45% of the PAH burden in suburban Tokyo, and that the increase in the biomass-PAH accounts for approximately 27% and 22% of winter-time elevation of LMW- and HMW-PAHs, respectively. These are far exceeding what is expected from the emission statistics for CO2 and combusted materials in Japan and emphasizing the importance of biomass-burning as a source of PAHs; which, in turn, demonstrates the utility and the significance of field-based source assessment by using CCSRA for an effective regulation of atmospheric pollution by PAHs.

Wash-off and sorptive behaviors of two benzothiazolamines (BTs) [i.e., 2-(4-morpholinyl)benzothiazole (24MoBT) and N-cyclohexyl-2-benzothiazolamine (NCBA)] have been investigated as possible molecular markersfortire debris and/or road dust transported in highway runoff water. Sum of dissolved and particulate 24MoBT and NCBA concentrations in runoff water ranged from 15 to 417ng/L and from 22to 508ng/L, respectively. Proportions of NCBA in particulate (>0.7microm) phase (<9-79%) were larger than that of 24MoBT (<1-14%), which was consistent with their experimentally determined octanol/water partition coefficients (Kow; 10(4.23+/-0.14) for NCBA; 10(2.42+/-0.03) for 24MoBT). The organic carbon-normalized in-situ partition coefficient (Koc') observed in runoff events (10(4.69+/-0.28) for NCBA; 10(3.42+/-0.23) for 24MoBT) were 1 order of magnitude higher than those expected from their Kow, indicating strong affinity of BTs to suspended particulate matter (SPM) in runoff water. Furthermore, in desorption experiments lasting 24 h, we observed almost the same levels of Koc' as those in runoff events, implying that significant fractions of BTs are strongly associated with runoff particles and not easily available to equilibrium partitioning. NCBA was ubiquitous in sediments from the Nogawa River receiving runoff from the Chuo Highway, whereas many of those samples had undetectable levels of 24MoBT. All of above results indicate that NCBA would be more suitable than 24MoBT as a molecular marker for runoff particles loading the aquatic environment. By using SPM-weighted mean concentration of particulate NCBA, at least 3.3+/-1.6% of the mass in the Nogawa sediments is estimated to be from runoff SPM.

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The laser-induced thermal lensing effect was applied to molybdenum blue colorimetry of phosphorus measurement. An Ar+ laser pumped rhodarnlne 101 laser was used as the heat and probe source. The signal from a silicon photocell with a 1 mm2 photosensitive surface, which was used as a laser radiation detector, was processed with an Inexpensive personal computer. The detection limit is 5 pg of P/mL which is determined mainly due to the deviation In the color development with the molybdenum blue method. The present method was applied to determine phosphorus in seawater and lake water.Methods for detecting trace phosphorus (nanogram level) in environmental samples Eire very limited. For exEimple, the spectroscopic technique did not reach the detection limit of 1 ng of phosphorus/mL in spite of many investigations using chemiluminescence, ICP, DCP, or AAS. Even nowadays, the most sensitive method is the classic molybdenum blue colorimetry based on the reduction of molybdenum in phosphor-molybdate. In combination with solvent extraction, determination of phosphorus at sub-part-per-billion levels is possible. However, even with this method, the concentration of phosphorus in some natural waters cannot be measured. In the environmental water system, the concentration of phosphoric acid necessary to induce eutrophication is sometimes less than a detectable amount. Among the various attempts to improve molybdenum blue colorimetry, the present study applied thermal lensing colorimetry using Ar+ laser pumped dye laser.LEiser-induced thermal lensing effect was first investigated by Gordon et al. (1), and it is pointed out that thermal lensing colorimetry is an important way to monitor small absorbance. Recently, Dovichi and Harris studied the theoretical aspects of various applications of thermal lensing colorimetry to analytical chemistry (2-4). Imasaka and Ishibashi reported the detection of iron by the thermal lensing effect (5, 6).Haushalter and Morris (7) applied thermal lensing colorimetry to monitor enzymatic reaction involving dopamine which could not be sensitively detected by other spectrometric methods, including fluorometry. Because of its high sensitivity, the feasibility for laser-induced thermal lensing colorimetry in environmetal analysis cannot be ignored. In a previous paper (8), we reported on thermEd lensing colorimetry of nitrite ions wherein color development was based on the diazo-coupling reaction. The detection limit of nitrite ions was thus improved about 500 times over ordinary colorimetry. In the present paper, determination of parts per trillion levels of phosphorus by the thermal lensing effect is discussed, along with signal processing by a personal computer. This method was applied to the analysis of phosphorus in seawater and lake water.