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A large scale of soil survey was performed to determine the contents, distributions and sources of 16 polycyclic aromatic hydrocarbons (PAHs) in 231 agricultural soils under 3 land-use types from 5 regions of the subtropical Pearl River Delta (PRD). The average sum of 16 PAHs in all soil samples is 316.5 micro g.kg(-1), with range from ND to 4079 micro g.kg(-1). Three- and 4-ring PAHs are the most abundant PAHs that contribute to 73.0% of total contents. The most abundant components are phenanthrene, benzo(b)fluoranthene and fluoranthene. ANOVA and principal component analyses (PCA) indicate that soil samples from Dongguan and Zhongshan contain greater PAHs than other regions. More abundant carcinogenic and higher molecular weight PAHs accumulated in soils from Dongguan and Zhongshan, while higher low molecular weight PAHs were in soils from Guanghzou, Huizhou and Shunde. Soil PAHs from 3 land uses are not statistically different. Additionally, 5 PAH compound ratios suggest that soil PAHs in PRD derived from mixture of pyrogenic and petrogenic sources, but the majorities are pyrogenic sources. PAHs were further identified as mixture of petroleum combustion and grass, wood, and coal combustion. Some soil PAHs were revealed vehicle emission, coal soot and petroleum sources. The 5 regions showed different PAHs sources according to some compound ratios, but no marked distinction between regions from 2 banks of the Pearl River because of major wind direction, distribution of riverway and industry.

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A polymer monolith microextraction method coupled with high-performance liquid chromatography was developed for the determination of adenosine triphosphate, adenosine diphosphate, and adenosine monophosphate. The monolithic column was synthesized inside fused-silica capillaries using thermal initiation free-radical polymerization with glycidyl methacrylate as the monomer, ethylene dimethacrylate as the cross-linker, cyclohexanol, and 1-dodecanol as the porogen. N-Methylolacrylamide, an important hydrophilic monomer, was incorporated into the polymerization mixture to enhance the hydrophilicity of the poly(glycidyl methacrylate-co-ethylene dimethacrylate) column. The obtained poly(glycidyl methacrylate-co-N-methylolacrylamide-co-ethylene dimethacrylate) monolith was characterized by scanning electron microscopy, Fourier-transform infrared spectra, and X-ray photoelectron spectroscopy. Optimum conditions for the preconcentration and separation of the target adenosines were also investigated. Under the optimum conditions, we obtained acceptable linearities, low limits of detection, and good relative standard deviations. The developed polymer monolith microextraction with high-performance liquid chromatography method exhibited a good performance with recovery values in the range of 76.9-104.7% when applied to the determination of the adenosines in five royal jelly samples.

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