ANYL 142 |
| The spectroscopic technique for pH measurement is preferable to the conventional electrode technique for very low or high ionic strength solutions as well as for samples at high temperatures and pressures. However, a limitation is that a single pH dye is sensitive only over a narrow pH range. Universal indicators, which are dye mixtures, are sensitive over a broad pH range but their accuracy is low. We have developed optimized dye mixtures that are both sensitive and accurate over a broad pH range. The measurement is robust and simple and requires a minimum of two wavelengths and is independent of concentration of dye mixture added. Optimization of the dye mixture formulation to maximize accuracy in the pH range of interest involves varying both dye type and its weight fraction. The technique has been successfully applied to measure pH of high temperature, pressure and ionic strength formation waters in oilfields. |
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General Papers
7:00 PM-9:00 PM, Sunday, 28 August 2005 Washington DC Convention Center -- Hall A, Poster
Division of Analytical Chemistry |