Publications by authors named "H Mitobe"

A simple method for quantitative analyses of organic chlorine pesticides (OCPs) in environmental water samples such as rainwater, river water and seawater using activated carbon fiber filters (ACFF) is described. ACFF was used as adsorbent to collect the chemicals in water samples. The collection of OCPs was completed almost for one day by stirring the mixture of the sample and the ACFF chips at room temperature.

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Article Synopsis
  • The study measured concentrations of persistent organic pollutants (POPs) in Niigata, Japan, from September 1999 to November 2001, finding HCB, alpha-HCH, t-CHL, and c-CHL consistently higher across all locations.
  • Higher levels of t-CHL and c-CHL in residential areas were linked to their past use as termiticides, while Yahiko, a remote site, had generally lower POP concentrations.
  • Most POPs decreased by 41-80% between 2000 and 2001, with seasonal variations showing higher concentrations in summer; the study found linear relationships linking POP levels with temperature changes.
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Water samples collected once a week from early April 1996 to the end of August 1996 from four sites on the Shinano River in Japan were analyzed for pesticides and their metabolites using a gas chromatograph-mass spectrometer. Among the total of 53 chemicals found, 22 were herbicides, 15 were insecticides, 11 were fungicides, and 5 were metabolites. The concentrations of chemicals found ranged from 3 ng/L (bromobutide) to 8200 ng/L (isoprothiolane).

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A new monitoring system was established for the determination of 90 pesticides and 10 pesticide degradation products in river water. The pesticides consisted of 18 fungicides, 30 insecticides, and 42 herbicides. The pesticides were extracted with a solid-phase, styrene-divinylbenzene copolymer, eluted with acetone, hexane, and ethyl acetate, and determined by gas chromatography/mass spectrometry.

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