Hajime Nishiyama’s research while affiliated with Tokyo University of Agriculture and other places

1 - CAPLUS AN 2002:943098(Journal)

Distributions of alkylphenols (APs) [i.e., nonylphenol (NP), octylphenol (OP)], and nonylphenol monoethoxylate (NP1EO) in wastewater effluents, river water, and riverine and bay sediments in the Tokyo metropolitan area were demonstrated. During sewage treatments, NP and OP were efficiently removed from the sewage effluents through activated sludge treatments. Greater removal for NP (93% on average) than OP (84% on average) was consistent with their partitioning behavior to particles in primary and secondary effluents. NP concentrations in the river water samples ranged from 0.051 to 1.08 microg/L with higher concentrations in summer and spring than in colder seasons. In the river water samples, approximately 20% of NP was found in the particulate phase. Organic carbon-normalized apparent partition coefficients (K'OC) for NP (10(5.22 +/- 0.38)) and OP (10(4.65 +/- 0.42)) were 1 order of magnitude higher than those expected from their octanol-water partition coefficients (K(OW)), indicating strong affinity of APs to aquatic particles. Among NP isomers, no significant differences in their K'OC values were suggested. This is consistent with surprisingly uniform isomer peak profiles among the technical standard and all the environmental samples analyzed. NP and OP were widely distributed in the river sediments in Tokyo, and relatively high concentrations (0.5-13.0 microg/g dry) of NP were observed in a long reach (approximately 10 km) in the Sumidagawa River. In situ production of APs in the river sediment was suggested. Seaward decreasing trend in APs concentration was observed from the estuary to the Tokyo Bay. APs were well preserved in a sediment core collected from the bay. The profile shows subsurface maximum of AP concentrations in the layer deposited around the mid-1970s. The recent decrease in AP concentrations can be attributed to the legal regulation of industrial wastewater in the early 1970s.

A comprehensive analytical method of endocrine disrupters (i.e., alkylphenols, phthalic acid esters, bisphenol A, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, DDTs) in environmental samples was developed. The method employs Soxhlet-extraction with dichloromethane and two-step-silica-gel and activated-charcoal column chromatography which provides eleven fractions, followed by determination on capillary GC equipped with MSD or ECD. The present method was applied to Tokyo Bay sediments. Most of the target compounds were identified and quantified clearly demonstrating the applicability to various environmental samples. Their concentrations are as follows: 4-t-octylphenol: 10.0 ng/g; 4-t-nonylphenol: 184 ng/g; benzyl n-butyl phthalate: 6.12 ng/g; dicyclohexyl phthalate: 2.56 ng/g; bisphenol A: 6.58 ng/g; benz[a]anthracene: 58.1 ng/g; benzo[a]pyrene: 93.7 ng/g; IUPAC#77 coplanar PCB: 0.82 ng/g; DDT: 0.42 ng/g; DDD: 1.00 ng/g; DDE: 1.37 ng/g. This method provides a powerful analytical tool to investigate a wide range of endocrine disrupters in samples of limited quantity.

A comprehensive anal. method of endocrine disruptors (i.e., alkylphenols, phthalic acid esters, bisphenol A, polycyclic arom. hydrocarbons, polychlorinated biphenyls, DDTs) in environmental samples was developed. The method employs Soxhlet-extn. with dichloromethane and two-step-silica-gel and activated-charcoal column chromatog., which provides eleven fractions, followed by detn. on capillary GC equipped with MSD or ECD. The present method was applied to Tokyo Bay sediments. Most of the target compds. were identified and quantified clearly, demonstrating the applicability of the method to environmental samples. Their concns. are as follows: 4-tert.-octylphenol 10.0 ng/g; 4-tert.-nonylphenol 184 ng/g; benzyl Bu phthalate: 6.12 ng/g; dicyclohexyl phthalate: 2.56 ng/g; bisphenol A: 6.58 ng/g; benz[a]anthracene: 58.1 ng/g; benzo[a]pyrene: 93.7 ng/g; IUPAC#77 coplanar PCB: 0.82 ng/g; DDT: 0.42 ng/g; DDD: 1.00 ng/g; DDE: 1.37 ng/g. This method provides a powerful anal. tool to investigate a wide range of endocrine disruptors in samples of limited quantity.