Investigations on Synthesized Azo Compound, [4-((4-Hydroxynaphthalen-1-yl) Diazenyl) Benzoic Acid] (p-ABAαN), as an Acid-Base Indicator

Aim: To evaluate the indicator properties of a synthesized azo compound to be used as a suitable substitute for standard indicators

Methodology: Compound, [4-((4-hydroxynaphthalen-1yl)diazenyl) benzoic acid](p-ABAαN) was synthesized using standard diazotization and coupling procedures. Initial evidence indicated that [4-((4-hydroxynaphthalen-1-yl) diazenyl benzoic acid] (p-ABAαN) exhibited sharp colour changes in acidic, neutral and alkaline pH media. Indicator properties in acid-base neutralization reactions were evaluated, and the results compared with that of phenolphthalein and methyl orange. The indicator, p-ABAαN was also used to assay Ibuprofen and validated upon comparison with official monograph (British Pharmacopoeia (2010) method). Results obtained were statistically analysed using t-test and One-Way Analysis Of Variance (One Way ANOVA) at 95% confidence level from Graph Pad Prism (version 6, 2012).

Results: The use of p-ABAαN in acid - base neutralization reactions involving strong acid / strong base and weak acid / strong base were experimentally verified and validated. Validation was also carried out for the use of p-ABAαN in titrimetric assay of Ibuprofen.

Conclusion: p-ABAαN [4-((4-hydroxynaphthalen-1-yl) diazenyl) benzoic acid] proved to be a suitable indicator for the titrimetric assay of Ibuprofen and in various acid-base titration experiments.