TITLE:
A Dual-Standard Reversed-Phase HPLC-UV Method for the Simultaneous Identification, Assay, and Impurities Analysis of Phenylboronic Acid: Using 4-Methoxyphenyl Boronic Acid as a Model Compound
AUTHORS:
Weijiang Ying, Maria Castelo, Jiangwei Li, Frank Wu
KEYWORDS:
Identification, Assay, Impurities, RP-HPLC-UV Analysis of Phenylboronic Acid, Dual-Standard
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.17 No.5,
May
28,
2026
ABSTRACT: Boronic acids (BAs) are versatile building blocks in organic synthesis and the pharmaceutical industry. A dual-standard reverse phase (RP) HPLC-UV method was developed for the simultaneous identification (as monomer), assay (as monomer), and impurities analysis of phenylboronic acid (PBA), using 4-methoxyphenyl boronic acid (4-MPBA) as a model compound. The method utilizes an Ascentis? Express 90 ? ES-Cyano column with 0.025% TFA in both mobile phases (A: water, B: methanol). It employs a simple gradient with an injection volume of 10 μL and a flow rate of 0.8 mL/min. This QC-friendly, single-sequence method achieves baseline separation of the analyte and its impurities. By utilizing a stable, readily available bromo-analog surrogate for quantitation, it bypasses the need for a single-component primary BA reference standard.