A Simple TLC—Densitometric Method for the Quantification of Acrylic Acid in Aqueous Solutions

Summary Because acrylic acid is a volatile organic compound, the precise quantification of acrylic acid by thin-layer chromatography (TLC) analysis is difficult. Herein, we report a simple TLC—densitometric method for the quantification of acrylic acid in aqueous solutions following a labeling procedure using the Mizoroki—Heck coupling reaction. To make acrylic acid nonvolatile and highly sensitive for ultraviolet (UV) detection, acrylic acid in an aqueous solution was reacted with iodobenzene in a dimethyl sulfoxide solution using a base (potassium carbonate) and a catalyst (FibreCat 1001), affording trans -cinnamic acid. High-performance liquid chromatography (HPLC) analysis showed that acrylic acid could be labeled over a range of 0.01–10 mM at 60°C for 30 min and the average reaction yield was 96.0%. To quantify acrylic acid by TLC analysis, the reaction mixture was extracted using ethyl acetate and then spotted on a silica gel 60 F 254 TLC plate. The spots corresponding to the labeled acrylic acid over a range of 0.1–1 mM on the TLC plate could be quantified under UV light at 254 nm. The detection limit was 0.1 nmol on the TLC plate. To evaluate the method developed, the concentrations of acrylic acid in environmental water samples after the contamination of 1 mM acrylic acid were determined by the proposed method. Compared to the results of the HPLC analysis, accuracy was estimated to be above 97.0% for all the analytes. Thus, the proposed method could be applied for the determination of acrylic acid in the environmental water samples without any interference from environmental components.