Spectrophotometric measurement of pH gradients in continuous-flow systems. Analytica Chimica Acta, 268(1):29-38, 1992. cited By 0
Spectrophotometric measurement of pH gradients in continuous-flow systems [link]Paper  doi  abstract   bibtex   
In the presence of an acid-base indicator and using fast diode-array spectrophotometric scans, pH gradients in the spectrophotometric cell can be measured at the same time as any other colorimetric flow-injection (FI) determination is performed. The effects of refractive index changes, adsorption-desorption processes at the tube walls and association of the indicator species with the system to be investigated are considered. Effective correction for the first two effects is demonstrated. Indicators with different molecular structures and polarities gave similar pH gradients, suggesting adequate accuracy for most potential applications. Application to the detection and correction of systematic and random errors in pH-sensitive FI procedures is demonstrated using the o-phthalaldehyde-N-acetyl-l-cysteine method for bovine serum albumin. © 1992.

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