Determination of acid value power system by indicator method
2018/5/15 Viewers:
When using indicator method to determine acid value of oil, alkali blue 6B and B.T.B (bromothymol blue) are used as indicators.
(1) an indicator used in the determination of Alkali Blue 6B, or CB264. For many years, alkali power 6B has been used as an indicator for the determination of acid value. But because of the discoloration range of the Alkali Blue 6B indicator in the non aqueous solution pHr (pHr is a special symbol for the non water solvent hydrogen ion words), the color is 9.5~10.3. red. In practice, it is shown that when the value of oleic acid is measured with Alkali Blue 6B, it is more suitable for new oil or oil with lighter color. The end point is not easy to judge in the face of oil in operation, that is, oil with deeper color, often the same oil sample. The error of the test results is larger than the operator.
(2) B, T.B indicator, the indicator used in the determination of GB7599-87. The color range of B.T and B indicator is in non-aqueous solution, pHr is 8.6-9.G., and its color is yellow and blue green, so it is suitable for oil with light color and deep color. At the time of titration, the transition color grade is less, the end point is clear and obvious, the result is easy to judge, the error of the result is small, and the solubility of B, T and B indicator is larger in the anhydrous B drunk. It is easy to make up and easy to operate. However, the pH value of each batch itself is very different, so the pH value of the prepared B and T.B indicator should be transferred to the 6.0. practice to explain the tartaric acid value of B, T and B indicator, which is closer to the potential commercial method than the alkaline blue 6B indicator.
(1) an indicator used in the determination of Alkali Blue 6B, or CB264. For many years, alkali power 6B has been used as an indicator for the determination of acid value. But because of the discoloration range of the Alkali Blue 6B indicator in the non aqueous solution pHr (pHr is a special symbol for the non water solvent hydrogen ion words), the color is 9.5~10.3. red. In practice, it is shown that when the value of oleic acid is measured with Alkali Blue 6B, it is more suitable for new oil or oil with lighter color. The end point is not easy to judge in the face of oil in operation, that is, oil with deeper color, often the same oil sample. The error of the test results is larger than the operator.
(2) B, T.B indicator, the indicator used in the determination of GB7599-87. The color range of B.T and B indicator is in non-aqueous solution, pHr is 8.6-9.G., and its color is yellow and blue green, so it is suitable for oil with light color and deep color. At the time of titration, the transition color grade is less, the end point is clear and obvious, the result is easy to judge, the error of the result is small, and the solubility of B, T and B indicator is larger in the anhydrous B drunk. It is easy to make up and easy to operate. However, the pH value of each batch itself is very different, so the pH value of the prepared B and T.B indicator should be transferred to the 6.0. practice to explain the tartaric acid value of B, T and B indicator, which is closer to the potential commercial method than the alkaline blue 6B indicator.
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