1998 Fiscal Year Final Research Report Summary
Development of chemical sensors for concentrated solutions
| Project/Area Number |
09650892
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
工業分析化学
|
|---|
| Research Institution | KYUSHU UNIVERSITY |
|---|
Principal Investigator |
IMATO Toshihiko Kyushu University, Graduate School of Engineering, Professor, 工学部, 教授 (50117066)
|
|---|
| Project Period (FY) |
1997 – 1998
|
| Keywords | Chemical Sensor / Potentiometry / Concentrated solution / pH sensor / Buffer solution |
|---|
| Research Abstract |
The purpose of this project is to develop chemical sensors for concentrated solution of acids, bases and redox compounds. The sensor consists of an inner electrode and an inner filling buffer solution prepared by polyelectrolyte, which are covered with a dialysis membrane. Followings are the summary of the results obtained by this project.
(1)Potentiometric sensors for redox compounds
The potentiometric sensors for hydrogen peroxide and ascorbic acid were developed. The sensors consist of a platinum electrode and a silver-silver chloride reference electrode as the inner electrodes and a potential buffer solution prepared by polystyrene sulfonic acid in Fe(II) and Fe(III) form as the inner filling solution. The end of the sensors was covered with a dialysis membrane (Viking membrane). The volume of the inner filling solution was less than 30 muL, which is capable to change by syringe pump. When the sensor was immersed into the hydrogen peroxide solution, hydrogen, hydrogen peroxide diffus
… More
ed into the inner filling solution across the dialysis membrane. The potential of the inner platinum electrode is changed as increasing concentration of hydrogen peroxide diffused due to oxidation of Fe(II) to Fe(III) with hydrogen peroxide after 30 min time lag. The potential change with time was found to be linear to the concentration of hydrogen peroxide in the range from 0.1 M to 1 M.Ascorbic acid was also successfully determined by the developed sensor.
(2)Potentiometric pH sensor for concentrated acids and bases
The similar pH sensor to the above sensor for redox compounds was developed. The inner filling solution is a pH buffer solution prepared by polyacrylic acid and polyacrylic acid sodium salt. An antimony electrode was uses as the inner electrode. The response of the developed pH sensor was examined by immersing the sensor into HCl solution of 2 M to 8 M.The potential change was observed to increase with increasing time after 3-5 min time lag when the sensor was immersed into the sample solution. The potential change with time was found to be linear to the concentration of HCl from 2 M to 8 M.The effective area and thickness of the dialysis membrane were found to be important factor to control the amount of HCl diffused in the inner filling solution. The pH sensor for concentrated sodium hydrooxide was also developed by using polyethyleneimin and its hydrochloride as the inner filling solution. Less
|
