Development of a Hydraulic-Drive Automatic Column Chromatography System for High Precision Isotope Analysis

This study presents a high-throughput automated open-column chromatography system designed for high-precision isotope analysis based on a hydraulic remote-drive mechanism. The system operates by using pressurized fluid to indirectly control eluent delivery, resulting in a completely metal-free separation unit that fully isolates metal components (pump, sensor, and valve) from corrosive acid solutions and vapors. This design effectively eliminates the corrosion and contamination risks inherent to conventional systems. Coupled with pressure sensing and mass flow feedback control, the hydraulic drive enables multichannel parallel elution (currently 8 channels) with high accuracy (error <3%) and excellent interchannel consistency (variation <0.5%). Constructed primarily from low-cost polymers, the system offers an economical and scalable platform for automated sample preparation. Validation using Cd and Cu isotope separation protocols demonstrated high recoveries (Cd: 97.5 ± 1.6%; Cu: 98.3 ± 1.4%) and low procedural blanks (Cd: 0.17 ng; Cu: 0.72 ng). Analysis of geological reference materials (e.g., BHVO-2, BCR-2, NOD-P-1) yielded isotopic ratios consistent with published values, confirming method reliability. Overall, the system provides a scalable, cost-effective, and metal-free platform for high-throughput separations required for high-precision isotope analysis.