Cysteamine recovery

Table V. Effect of solvent volume and cysteamine quantity on thiazolidine recovery from solvents...

Effect of Derivatization pH on Aldehyde Recovery. Binding of aldehydes to other wine components (SOj, phenols, etc.) is highly pH dependent, therefore the effect of pH on derivatization efficiency was evaluated. Following addition of aqueous cysteamine to spiked wine samples, the pH was adjusted to 2, 8, or 10, and the solutions were allowed to react for 1 hour. The pH of all samples was then readjusted to 8.5, and the samples were extracted and analyzed as described above. Initial results indicated that no consistent differences in recovery at the different pH s were observed, however, overall variability appeared greater at pH 2. These results provide preliminary evidence that the total aldehyde concentration (free plus bound) is measured with this procedure. Further studies with model solutions containing added SO2 and phenols are needed to fully evaluate this result. 

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