Analytical procedure for tracing acrylamide and sulfonated co-polymers in groundwater affected by chemical enhanced oil recovery activities

Polymer flooding emerges as one of the most utilized chemical enhanced oil recovery (cEOR) techniques. The implementation of acrylamide and sulfonated co-polymers holds promise in polymer flooding due to their capacity to withstand high temperatures and salinities. Taking environmental concerns into account, monitoring the quality and contamination of groundwater becomes crucial and challenging after the cEOR processes. In this study, we developed a method for the determination of acrylamide and sulfonated co-polymers potentially contaminating groundwater using high-performance liquid chromatography with diode-array detection (HPLC-DAD). To achieve the sensitivity required for such a demanding task, key parameters including the detection wavelength, mobile phase ratio, injection volume, flow rate, and temperature were optimized, which resulted in the values of 195 nm, 70% acetonitrile in pure water, 20 μL, 1 mL/min, and 30 °C, respectively. The chromatographic process was completed within a short 5-min analysis time, allowing for readily increased sample throughput. Moreover, the accuracy and precision of the proposed method for the determination of target polymers in groundwater samples were demonstrated, and the criteria were satisfactorily met in accordance with AOAC guidelines.