2.13. Acid and alkali degradation studies
1.0 mL of methanolic stock solution of curcumin was added into two flasks. 1.0 mL of 3 M HCl or 1.0 mL of 3 M NaOH was added separately into each of the flask. The solutions were neutralized immediately and adjusted to volume with methanol. These samples served as zero hour samples. Another set of flasks was left on the bench at room temperature (26 C/65% RH) and the same neutralization procedure was repeated after 24 h. The neutralized solutions were injected in triplicate.