1982 Volume 11 Issue 2 Pages 138-143
We studied assay method of urinary p-aminobenzoic acid (PABA) in PFD Test which is very significant for the assessment of exocrine pancreatic function.
At first, urinary conjugated PABA was hydrolyzed with 2.5 N hydrochloric acid. Then followed sodium nitrate soln. and colored soln. which contained 1-naphthol-2-sulfonate were added to a portion of the hydrolysate. 1-Naphthol-2-sulfonate reacted with PABA by diazo coupling reaction and yielded a chromogen with max. absorption at 505nm.
Linearity was maintained up to 100 mg/dl of PABA. Additional recovery of PABA was 96.5-101.6% and that of p-acetamidobenzoic acid was 98.8-99.9%.
The reproducibility of the method was satisfied (C.V. 0.665% at 58.6mg/dl).
