title: Simultaneous determination of nine related substances in p-phthalic acid residue by RP-HPLC.
abstract: A high-performance liquid chromatography with ultraviolet detection (HPLC-UV) is established for the simultaneous determination of p-phthalic acid, benzoic acid, 4-carboxybenzaldehyde, m-phthalic acid, o-phthalic acid, phthalide, o-toluic acid, m-toluic acid and p-toluic acid in the residue generated during the production of p-phthalic acid (PPA). On a narrow-diameter reversed-phase C18 column, gradient elution is applied with a methanol-water-ammonium acetate-acetic acid buffer (100 mmol/L, pH 4.70) as mobile phase at a flow rate of 0.2 mL/min, and detection is operated by UV absorption at a wavelength of 254 nm. Under the conditions, these nine relative compounds, including organic acids, are well separated. The detection limits (S/N = 3) are 0.05 µg/mL-0.20 µg/mL, and the correlation coefficients of standard curves are between 0.99995 and 0.99999. Relative standard deviations for analyses of real samples are below 5.3%, and recoveries of these determined compounds ranges from 90.0 to 104.9%. The method, which provides accurate and reliable results, can effectively guide the recycling and reutilization of organic acids and related substances in PPA residue.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry & Chemical Engineering and Center of Materials Analysis, Nanjing University, 22 Hankou Road, Nanjing 210093, China.
authors.forename: Na
authors.initials: N
authors.lastname: Yuan
authors.forename: Jun-Qin
authors.initials: JQ
authors.lastname: Qiao
authors.forename: Hong-Zhen
authors.initials: HZ
authors.lastname: Lian