Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants whose carcinogenicity and mutagenicity have been extensively studied. 1They are byproducts of the incomplete combustion of fuels and wood, and persist in the environment. 2 The concentrations of PAHs in the atmosphere are regarded as indicators of air pollution, and the historical trends of PAHs recorded in the sediment core from a reservoir should reflect the changes in the atmospheric pollution around the reservoir. 3 In order to evaluate the atmospheric environment at the sampling point and the historical trend of the PAH risk in the atmospheric environment, it is very important to establish an analytical method for PAHs in sediment samples.Tsuji et al. reported a method for the determination of PAHs in sediment using ultrasonic extraction of the PAHs and a cleanup solid-phase extraction procedure, followed by LC/fluorescence detector. 4 However, it is difficult to detect PAHs which have a poor fluorescence, such as indeno [1,2,3-c,d]pyrene, using the fluorescence detector.The LC/MS method would supply more useful information for the analysis of PAHs because of the relatively high specificity of the MS detector compared to the UV or fluorescence detector. However, very few examples are known based on the detection of PAHs by LC/MS using several commercially available interfaces, including thermospray, 5 liquid ionization 6 and atmospheric pressure chemical ionization.7 Furthermore, there were only a few reports about the detection of PAHs using electrospray as the interface due to difficulty of ionizing low polar compounds. 8,9 Recently, Bruins et al. introduced the dopant assisted atmospheric pressure photoionization (APPI) technique, which was a novel LC/MS ionization and can achieve the ionization of low polar compounds, such as PAHs. 10,11 However, there are few reports on the application of this technique to environmental analysis. 12 In this report, we present a method for the determination of PAHs in sediment samples by the ultrasonic extraction of PAHs and a clean-up solid-phase extraction procedure followed by LC/APPI/MS. Experimental MaterialsThe following 12 PAHs were detected and determined in this study: phenanthrene (Phe), anthracene (An), fluoranthene (Flu), pyrene (Py), benzo(a)anthracene (B(a)A), chrysene (Chr), benzo(b)fluoranthene (B(b)F), benzo(k)fluoranthene (B(k)F), benzo(a)pyrene (B(a)P), benzo(e)pyrene (B(e)P), benzo(ghi)perylene (BghiP) and indeno [1,2,3-c,d]pyrene (IP). These compounds were obtained from SUPELCO (Tokyo, Japan). All solvents were of HPLC grade, while the other chemicals were of analytical-reagent grade. Benzo(a)pyrene-d12 was used as the internal standard, and purchased from Hayashi Pure Chemical Industries (Osaka, Japan). Ammonium acetate and acetic acid were obtained from Wako Pure Chemical (Osaka, Japan). Ultra-pure water was produced by a Milli-Q system (Millipore, Bedford, USA). A sediment sample was obtained from Nagaike, which is a reservoir located in the southern part of Osaka C...

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Heavy metal concentrations of the acidsoluble fraction in sediment core samples from Nagaike, a reservoir in Osaka City, Japan, were measured by ICP-MS following the microwave extraction method. Spiked peaks for several metals in the sediment core samples were observed around 1960. The results of correlation coefficient study and cluster analysis of heavy metal concentrations in the sediment core samples showed that some metals, such as Cr, Cd, Ni and Cu, in the period of the spiked peak were derived from the different emission sources from other periods. These metals are often used for metal plating, and it was concluded that the spiked peaks were caused by illegal effluent from the metal plating industry. The load amounts of heavy metals by illegal dumping were calculated and the magnitude of the pollution was estimated.

Metal concentrations in a sediment core from a moat outside Osaka Castle in Japan were measured by ICP-MS following a microwave extraction method. Concentrations of metals in the sediment core samples peaked around 1945 when the World War II ended. This is in part due to great air raids on Osaka. In cluster analysis using metal concentrations, the fractions of sediment core samples were classified into two groups, representing natural sources and anthropogenic sources , respectively. Results of lead isotope ratios also showed the anthropogenic influences from 1915 by changing the ratio values compared to those of natural sources. In addition, several components contributing to metal concentrations were identified by principal component analysis. The main component was controlled by natural sources and a decrease of the component score corresponded to an increased influence from anthropogenic sources. The largest impact of anthropogenic sources was shown around 1945.

Sediment core samples were obtained from Nishiyama Reservoir, 3 km east of the hypocenter of the Nagasaki atomic bomb, to evaluate both sources and inventories of lead delivery to the sediments. Using microwave digestions and ICP-MS analytical techniques, elevated concentrations of isotopically unique lead were identified in the 1945 sediment horizon. These results illustrate that the Nagasaki bomb attack can be linked with unique lead loading to the sediments in the region of the hypocenter. There is a possibility that the roll-up of in-situ lead accounted for a majority of the increase in lead flux delivered to reservoir sediments during the atomic bomb attack.