Modern automated sample preparation for the determination of organic compounds: A review on robotic and on-flow systems

Sample preparation is crucial for reliable and confident analytical methods, ensuring selective enrichment, clean-up, and removal of matrix interferents. However, it often involves labor-intensive, error-prone procedures. Automation of sample preparation improves throughput, precision, and accuracy while reducing health risks associated with hazardous chemicals or biological agents. Robotic systems and on-flow techniques are two common approaches for automating sample preparation in chromatography and mass spectrometry. Robotic systems are versatile automation platforms with mobile parts for performing chemical operations. Many commercial solutions are currently available, and open-source prototyping enables the affordable development and implementation of lab robots. On-flow techniques encompass a variety of strategies based on pumps and valves, with column-switching being particularly effective for the direct injection of raw samples and the online integration of extraction/preconcentration and separation stages. This review provides an update on the latest advances in sample preparation automation, introduces and explains the main automation strategies, highlights selected applications, and outlines their scope and limitations. Recent advancements in the use of robots and on-flow techniques in the automation of sample preparation for analyzing organic compounds via liquid chromatography and mass spectrometry are discussed, including applications, limitations, and future trends. Lastly, it presents trends and insights into future advancements.