Python-controlled, solvent-resistant fraction collector for automated flow synthesis

Abstract

Flow chemistry has emerged as a powerful approach for high-throughput and automated synthesis workflows. However, downstream fraction collection remains a practical challenge: commercial systems are often expensive and difficult to integrate, while most low-cost or DIY alternatives lack compatibility with common organic solvents and real-time control. Here, we present a solvent-resistant, Python-controlled fraction collector built from low-cost, modular components (∼$1000). The system integrates programmable vial positioning and real-time volumetric monitoring to enable accurate, flow-independent fraction collection. Performance was validated across a range of flow rates (0.1–6 mL min⁻¹) and viscosities (0.45–500 cP), with consistent droplet mass and high reproducibility. It also achieves high separation fidelity, with sharp fluid transitions and negligible carryover between fractions under both aqueous and organic conditions. This open-source platform offers a robust, integrable solution for automated flow synthesis and supports broader adoption of continuous, data-rich experimentation in organic chemistry.