CoMetro CF-2 Fraction Collector

Overview

The CoMetro CF-2 Fraction Collector is a precision-engineered, low-power fractionation module designed for integration into preparative liquid chromatography (prep-LC), gravity-fed column chromatography, and open-bed separation systems. It operates on the principle of synchronized eluent detection and discrete fraction collection—enabling reproducible, event-triggered sample capture based on real-time signal input from UV-Vis detectors (e.g., Spectra/Chrom 280), conductivity meters, or pH sensors. Unlike continuous fraction collectors, the CF-2 employs drop-count logic as its primary deterministic trigger, offering high temporal resolution without reliance on flow rate calibration—a critical advantage when handling variable or low-flow separations (e.g., flash chromatography at 1–5 mL/min or gravity elution). Its sub-10 W power draw and condensation-free internal architecture allow uninterrupted operation inside refrigerated environments (e.g., 4 °C cold rooms), eliminating thermal drift in temperature-sensitive biomolecule isolation workflows.

Key Features

• Three configurable collection modes: drop count (1–9999 drops, 1-drop increment), time (6 sec – 999 min 59 sec, 1-sec resolution), and detector-synchronized peak gating (requires external analog/digital signal input)
• Ultra-fast tube switching: 0.35 s between adjacent 12/13 mm tubes, minimizing inter-fraction carryover and preserving peak integrity
• Rugged mechanical construction: anodized aluminum chassis with stainless steel actuation components ensures long-term dimensional stability and corrosion resistance
• Modular accessory ecosystem: supports optional 3-way split valves (#124849, #124838) for peak-only collection, 2-way shut-off valves (#124848) for flow termination during tube changeovers, and 4-column adapter (#124876) for parallel multi-column processing (29 fractions per column)
• Low-noise stepper-motor drive system (<35 dB(A)) suitable for shared laboratory spaces and automated unattended runs
• Extension mounting bracket (#124874) enables secure co-location with UV detectors, fraction sensors, or fraction identification modules without additional bench space

Sample Compatibility & Compliance

The CF-2 accommodates standard chromatographic consumables across multiple formats: 174-position racks for 12/13 mm round-bottom tubes (Cat. #124853), 116-position racks for 10–11 mm or 17–18 mm tubes (Cat. #124854–#124855), and 42-position flash vial trays (Cat. #124856). Its open-interface design permits seamless integration with third-party HPLC systems (e.g., Agilent 1260, Waters Prep 150), medium-pressure LC systems, and custom-built gravity columns. All electrical components comply with IEC 61010-1 safety standards; CE marking confirms conformity with EU electromagnetic compatibility (EMC) Directive 2014/30/EU and Low Voltage Directive 2014/35/EU. While the CF-2 itself does not store audit trails, its analog/digital trigger inputs support connection to FDA 21 CFR Part 11-compliant data acquisition systems when deployed in regulated GMP/GLP environments.

Software & Data Management

The CF-2 operates as a hardware controller with no embedded operating system or onboard software—ensuring deterministic timing and eliminating firmware-related latency or security vulnerabilities. Collection events are initiated via TTL-level digital pulses or 0–10 V analog signals from compatible detectors. For laboratories requiring electronic recordkeeping, the unit interfaces directly with Chromatography Data Systems (CDS) such as Empower, Chromeleon, or OpenLab via standard BNC or DB9 connectors. Trigger logs—including timestamp, tube position, and mode selection—are captured externally by the host CDS. Optional accessories like the 3-way split valve enable conditional fraction routing (e.g., “collect only when absorbance > 200 mAU”), reducing manual post-run sorting and supporting lean lab practices.

Applications

• Purification of natural products (alkaloids, flavonoids, terpenes) via silica or reversed-phase flash chromatography
• Isolation of monoclonal antibody fragments following protein A/G affinity chromatography
• Collection of pooled fractions for subsequent MALDI-TOF MS or NMR analysis
• Multi-column parallel purification of synthetic oligonucleotides or peptide libraries
• Automated fraction recovery in teaching labs where reliability and ease of maintenance are prioritized over full software integration

FAQ

Can the CF-2 be used with both low-pressure and high-pressure chromatography systems?
Yes—the CF-2 accepts eluent streams up to 100 psi (6.9 bar) when paired with appropriate pressure-rated tubing and valves. Its drop-count mode eliminates flow-rate dependency, making it especially suitable for gravity-fed or low-flow pump systems.
Does the CF-2 support volume-based collection without external flow meters?
No—volume-based collection requires integration with a calibrated flow sensor or mass flow controller providing pulse output proportional to volumetric throughput.
Is the 4-column adapter compatible with all tube rack configurations?
The 4-column adapter (#124876) is designed exclusively for use with the 174-tube rack (#124853) and requires the extension mounting bracket (#124874) for stable alignment across all four collection channels.
What is the minimum detectable drop size the liquid drop counter can resolve?
The integrated optical drop counter reliably detects aqueous or organic droplets ≥15 µL under standard eluent viscosity conditions (e.g., MeOH/H₂O, ACN/H₂O); performance may vary with highly viscous solvents (e.g., DMSO, glycerol mixtures).
Can the CF-2 operate unattended overnight?
Yes—its solid-state electronics, passive cooling design, and fail-safe valve options (e.g., #124848 shut-off valve) support extended unattended operation, provided the connected detector and pump systems are similarly validated for overnight use.