Accuracy Spectrophotometric Determination of pH for Sea Water
| Project/Area Number |
05640555
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
地球化学
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| Research Institution | Kinki University |
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Principal Investigator |
YAMAZAKI Hideo Kinki University, Faculty of Science and Technology, Lecturer, 理工学部, 講師 (30140312)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1994: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1993: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | pH / Sea Water / pH Indicator / Spectrophotometric Method / Hydrogen Ion Concentration / 分光測光法 / pH測定 / 分光光度法 |
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| Research Abstract |
The pH of sea water was accurately determined from spectrophotometric measurement. The measurement of pH of the analyte solution was achieved by the spectrophotometric method using thymol blue as a pH indicator. Advantage was taken of the redundant data available with digitized spectra. The calculations of pH and its statistical errors were performed using the spreadsheet software. Statistically photometric errors of the pH measurement of sea water was estimated to be <plus-minus>0.00015 pH units. Because of limited by errors in the K_a evaluation of thymol blue, the overall accuracy of this method was <plus-minus>0.00072 pH at 25ﾟC,and salinities between 0 to 40 *. One aspect of pH measurement often ignored is the low reliability of glass electrode pH reading at high ionic strength sample. The use of spectral method can circumvent some of the difficulties. Accurate and reliable determination of the pH of sea water is necessary for the reveal of chemical process in the ocean. Currently, I am extending this approach to development of a new optical pH sensor.
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Report
(3 results)
Research Products
(7 results)
