Research

We identify source and investigate behavior in the environment for chemical compounds by measuring the stable isotopic ratios in pesticides, suspended particulate matter, volatile organic compounds (VOCs), and foods using stable isotope ratio mass spectrometry. The research theme in our laboratory is mainly divided to four as follows.


Topics 1

Source apportionment for aerosol using stable isotope ratio


We research source apportionment and environmental dynamics using carbon and nitrogen stable isotopic ratios in aerosol (suspended particulate matter). Suspended particulate matter is a composite of complicated compounds such as water-soluble ion, heavy metals, elemental carbon, organic carbon etc. In this study, we are developing new method for analyzing carbon stable isotope ratios in elemental carbon, and nitrogen stable isotopic ratios in ammonium and nitrate. From these studies, we estimate transcontinental pollution caused by coal burning (for heating) from China continues in winter. Recently, we investigate nitrogen isotope ratio in ammonium and nitrate using highly sensitive and accurate analysis using bacteria called denitrifying bacteria method.

I visited and was taught by Professor Keisuke Koba in Kyoto University and Associate Professor Karen Casciotti in Stanford University and was able to do it in Akita prefectural university. In addition, we are conducting research in collaboration with Malaysia and Bangladesh using these methods.


Topics 2

Development of analytical method for stable isotope ratio using LC/IRMS

We develop new method to distinguish between domestic or overseas production for pesticides and identification method for pesticides in environment using stable isotope ratio . We developed analytical method of stable isotope ratio in pesticides using GC/IRMS under highly accuracy and precision.
We used this method in cases of methamidophos contamination of frozen dumplings incident and malathion contamination


Topics 3

Source identification for pesticide using stable isotope ratio

We develop new method to distinguish between domestic or overseas production for pesticides and identification method for pesticides in environment using stable isotope ratio . We developed analytical method of stable isotope ratio in pesticides using GC/IRMS under highly accuracy and precision.
We used this method in cases of methamidophos contamination of frozen dumplings incident and malathion contamination of frozen pizza incident in Japan. We can identify each product by using stable isotopic ratios of pesticides. Recently, LC/IRMS were developed. We are also analyzing the stable isotopic ratios in soluble pesticide.


Topics 4

Source apportionment for VOCs using stable isotope ratio

Volatile organic compounds (VOCs) are consisted to complicated compounds such as benzene, which is a carcinogen, and toluene, which is a neurogenic substance. In this study, we developed analytical method for carbon and hydrogen stable isotope ratios in benzene and toluene in exhaust gas and ambient environment. We investigated the environmental dynamics of these components. Especially, benzene and toluene react and disappear by photochemical reaction, we investigate isotopic fractionation during that time.