CoMetro CF-2 Automated Fraction Collector

Overview

The CoMetro CF-2 Automated Fraction Collector is a precision-engineered, modular fraction collection system designed for integration into preparative liquid chromatography (LC), flash chromatography, and gravity-fed column chromatography workflows. It operates on a dual-mode collection principle—supporting both drop-count-based and time-based fractionation—with programmable thresholds for real-time, detector-triggered collection. The instrument employs optical drop sensing technology to detect individual droplets with high reproducibility, enabling accurate synchronization with UV/VIS absorbance signals from compatible detectors such as the Spectra/Chrom 280. Its low-power architecture (<10 W) ensures stable operation in refrigerated environments (e.g., cold rooms at 4 °C), without condensation buildup or thermal load on adjacent cooling systems—a critical design consideration for long-duration, temperature-sensitive separations.

Key Features

• Multi-parameter collection logic: configurable by drop count (1–9999), elapsed time (6 sec–999 min 59 sec), or external TTL/relay trigger input from UV detectors
• Sub-350 ms tube switching time for 12/13 mm diameter tubes—minimizing carryover and preserving fraction integrity during high-resolution separations
• Robust mechanical construction using anodized aluminum frame and stainless-steel components for chemical resistance and long-term dimensional stability
• Modular accessory ecosystem including 3-way flow diverters (standard and high-flow variants), 2-way shut-off valves, 4-column adapter kits, and extendable mounting brackets for detector alignment
• Integrated optical drop counter with adjustable sensitivity and debounce filtering to accommodate variable flow rates (0.1–20 mL/min typical)
• Compact footprint (28 × 12 × 38 cm) and lightweight design (5 kg) facilitate benchtop deployment in space-constrained laboratories or mobile purification setups

Sample Compatibility & Compliance

The CF-2 accommodates a broad range of container formats via interchangeable tube racks: up to 174 × 12/13 mm test tubes, 116 × 10–11 mm or 17–18 mm tubes, or 42 × 28 mm scintillation vials. Its open-architecture interface supports analog (0–10 V, ±5 V) and digital (TTL, relay closure) output signals from third-party UV, conductivity, or refractive index detectors—ensuring compatibility with major chromatography platforms including Biotage®, Teledyne ISCO®, and custom-built systems. While not certified under ISO/IEC 17025 or FDA 21 CFR Part 11 out-of-the-box, the CF-2’s deterministic timing behavior, non-volatile parameter storage, and hardware-level valve actuation enable validation-ready operation in GLP- and GMP-aligned environments when deployed with documented SOPs and audit-trail-enabled software extensions.

Software & Data Management

The CF-2 operates as a standalone hardware controller with front-panel keypad navigation and LED status indicators—eliminating dependency on host computers for basic operation. All collection parameters (drop thresholds, dwell times, tube indexing logic) are retained in non-volatile memory across power cycles. For enhanced traceability, optional PC-based configuration utilities support CSV export of run logs—including timestamped tube indices, trigger events, and valve state transitions. When paired with peak-detection-capable detectors (e.g., Spectra/Chrom 280), the CF-2 can execute conditional collection strategies: e.g., “collect 5 drops during baseline, switch to 15-drop windows during UV peaks.” This functionality reduces post-run fraction consolidation effort and improves downstream analytical efficiency.

Applications

• Purification of natural products, synthetic intermediates, and biologics via silica- or reversed-phase preparative HPLC and flash chromatography
• Automated collection of eluent fractions for parallel NMR sample preparation, MS analysis, or bioactivity screening
• Multi-column parallel purification workflows using the optional 4-column adapter—enabling simultaneous fractionation across orthogonal separation conditions
• Low-temperature biomolecule isolation (e.g., enzymes, antibodies) in cold-room installations where thermal drift must be minimized
• Method development support through rapid iteration of collection windows based on real-time UV trace evaluation

FAQ

Can the CF-2 be used with non-CoMetro detectors?
Yes—the CF-2 accepts standard analog voltage inputs (0–10 V) and TTL/relay triggers from most commercial UV, fluorescence, and conductivity detectors.
Is the tube rack included with all configurations?
No—only models 124845 (115 V) and 124846 (230 V) include the 174-position tube rack and optical drop sensor. Rack-only options (e.g., 124853) are available separately.
What is the minimum detectable flow rate for reliable drop counting?
The optical sensor reliably detects discrete drops at flow rates ≥0.1 mL/min with aqueous or low-viscosity organic solvents; performance may vary with highly viscous or opaque mobile phases.
Does the CF-2 support volume-based collection?
Not natively—volume collection requires calibration of drop volume per solvent system and subsequent conversion to drop count; it does not incorporate integrated flow meters or gravimetric feedback.
Can the instrument be validated for regulated pharmaceutical use?
While the CF-2 lacks embedded electronic signatures or audit trails, its deterministic hardware control, parameter persistence, and compatibility with 21 CFR Part 11-compliant data acquisition systems make it suitable for inclusion in validated chromatographic purification processes when supported by appropriate procedural controls.