[Determination of acrylic acid from catalytic preparation lactic acid by anion-exchange chromatography]

Acrylic acid is a kind of important monomer and basic organic chemical raw material. In the process of catalytic preparation of acrylic acid from lactic acid, in order to monitor the catalytic process effectively and timely, an anion-exchange chromatographic (AEC) method has been established for the simultaneous determination of lactic acid and acrylic acid. The separation was carried out on a Metrohm A Supp 5 anion-exchange column (150 mm x 4.0 mm) with 2 mmol/L Na2CO3 +2 mmol/L NaHCO3 as the mobile phase. The flow rate of the mobile phase was 0.7 mL/min. A chemically suppressed conductivity detector was used. The linear ranges of calibration curves were 0.1-500 mg/L for lactic acid and 0.1-200 mg/L for acrylic acid. The detection limits with S/N = 3 were 0.030 mg/L for lactic acid and 0. 035 mg/L for acrylic acid. The recoveries of lactic acid and acrylic acid were 100.7%-106% and 99.6%-103% with the relative standard deviations of 2.16%-2.49% and 2.42%-2.48%, respectively. This method is accurate, speedy, sensitive and reproducible, and has been successfully used for the determination of lactic acid and acrylic acid in the catalytic reaction product.