Gas Chromatographic Method for the Analysis of Organic Acids in the Bio-Catalytic Conversion Process

An analytical method for the quantification of acrylic acid (AA), 1,3-propanediol (1,3-PD) and 3-hydroxypropionic acid (3-HP) in the bio-catalytic conversion process has been developed by gas chromatography. A simple liquid-liquid extraction (LLE) procedure was used in the sample preparation. Organic acid additives such as trifluoroacetic acid were used to improve the extraction efficiency in the LLE procedure. Under optimum analysis conditions, all analytes were satisfactorily separated with no interference. In standard calibration, all correlation coefficients (r(2)) were better than or equal to 0.994. In culture media, the intra-batch precision (% relative standard deviation) and recovery (%) as the average value of the quality control samples were 2.3 and 102.4%, respectively. In addition, the inter-batch precision and recovery as the average value of the quality control samples were 5.0 and 104.0%, respectively. In phosphate buffer, the intra-batch precision and recovery as the average value of the quality control samples were 2.7 and 101.6%, respectively. In addition, the inter-batch precision and recovery as the average value of the quality control samples were 2.9 and 101.7%, respectively. The limit of detection (S/N ratio: 3) and limit of quantification (S/N ratio: 10) were 1.0 and 3.5 µg/mL, 3.0 and 10.0 µg/mL, and 9.0 and 30.0 µg/mL, respectively, for AA, 1,3-PD and 3-HP. Consequently, this method was demonstrated to be acceptable for the quantitative analysis of AA, 1,3-PD and 3-HP in culture media and phosphate buffer.