CoMetro CP-LDI Parallel Dual-Head Piston Pump for HPLC and Preparative Chromatography

Overview

The CoMetro CP-LDI is a high-pressure, parallel dual-head piston pump engineered for precision flow delivery in analytical and preparative liquid chromatography systems—including HPLC, UHPLC-compatible setups, and medium-pressure purification workflows. Operating on positive displacement principles, the CP-LDI utilizes two independently actuated, synchronized stainless-steel piston assemblies mounted in parallel configuration to deliver stable, pulse-free solvent flow across wide dynamic ranges. Its hydraulic architecture minimizes dwell volume and compressibility-induced flow deviation through real-time compression compensation algorithms, enabling accurate gradient formation and reproducible retention time alignment—critical for method transfer and regulatory-compliant separations.

Key Features

• Parallel dual-piston head design ensures redundancy, extended service intervals, and balanced mechanical load distribution—reducing wear on seals and plunger rods.
• Electronically controlled brushless DC motor drive with closed-loop torque feedback delivers consistent speed control across the full pressure range (up to 6000 psi / 414 bar).
• Integrated high-sensitivity piezoresistive pressure transducer enables continuous real-time monitoring with programmable upper/lower pressure limits and automatic shutdown on overpressure events.
• Front-panel keypad with intuitive menu navigation supports rapid setup of flow rate, pressure limits, compression factor, display brightness, and unit selection (PSI, MPa, bar).
• Multi-mode control architecture: local operation via keypad; remote operation via RS-232 or USB serial communication; external analog control (0–5 V DC or 4–20 mA) for integration into custom automation platforms.
• On-demand self-cleaning cycle—triggered manually or scheduled—flushes pump heads with wash solvent to remove crystallized buffer salts, significantly extending seal life and minimizing downtime in phosphate- or acetate-based mobile phases.

Sample Compatibility & Compliance

The CP-LDI is compatible with a broad spectrum of HPLC-grade solvents (including acetonitrile, methanol, water, THF, and chlorinated organics), as well as aqueous buffers (e.g., ammonium acetate, sodium phosphate, TFA) when used with optional inert-wetted materials (e.g., sapphire check valves, PEEK or Hastelloy fluidic paths). Its pressure and flow stability meet the operational requirements of ASTM D7597 (Standard Test Method for Determination of Hydrocarbon Types in Middle Distillates by Supercritical Fluid Chromatography), ISO 13877 (Liquid Chromatography — Terminology and Definitions), and USP Chromatography. The pump’s firmware supports audit-trail-enabled operation when connected to compliant LIMS or CDS software, facilitating adherence to FDA 21 CFR Part 11 and GLP/GMP documentation standards.

Software & Data Management

The CP-LDI communicates via ASCII-based command protocol over RS-232 or virtual COM port (USB), allowing seamless integration with third-party chromatography data systems (CDS) such as Chromeleon, Empower, or OpenLab. Optional CoMetro PumpControl Suite (v3.x) provides graphical configuration, method storage (up to 99 user-defined methods), real-time pressure/flow trend logging (CSV export), and event-triggered alerts (e.g., pressure deviation >±5%, low solvent level detection). All parameter changes—including flow setpoints, pressure limits, and compression compensation values—are timestamped and logged with operator ID fields, supporting traceability in regulated environments.

Applications

• Analytical-scale reversed-phase and HILIC separations requiring sub-1% RSD flow stability.
• Semi-preparative purification (10–50 mm ID columns) of natural products, peptides, and synthetic intermediates under gradients up to 200 mL/min.
• Multi-pump gradient systems: Up to four CP-LDI units can be synchronized via master-slave timing protocols to construct ternary or quaternary solvent gradients for complex sample matrices.
• Method development labs where flexibility across flow ranges (0.001–12 mL/min for capillary/nano-LC; 0.1–200 mL/min for prep-LC) eliminates need for multiple dedicated pumps.
• QC/QA laboratories performing compendial assays per USP, EP, or JP monographs where flow accuracy (±1%) and inter-day precision (≤0.1% RSD) are documented performance criteria.

FAQ

What flow rate ranges are available on the CP-LDI, and how are they selected?
The CP-LDI offers three factory-configurable flow ranges: 0.001–12 mL/min, 0.1–100 mL/min, and 0.1–200 mL/min. Range selection is performed during installation using dip-switch settings inside the pump housing and requires recalibration of the pressure transducer and flow sensor.
Does the CP-LDI support gradient mixing at the pump head?
No—the CP-LDI is a constant-flow binary or quaternary pump platform; gradient formation occurs externally via proportioning valves or low-dead-volume mixers upstream of the column. It does not incorporate integrated mixing chambers.
Can the CP-LDI be operated without a computer connection?
Yes—full standalone operation is supported via the front-panel keypad. All critical parameters (flow, pressure limits, compression compensation) are adjustable and retained in non-volatile memory after power cycling.
Is the pump compatible with aggressive solvents such as concentrated acids or halogenated hydrocarbons?
Standard wetted materials (316L SS, sapphire, PTFE) are suitable for most common HPLC solvents. For prolonged exposure to >10% TFA, HFIP, or chloroform, optional Hastelloy C-276 pump heads and PEEK-lined tubing are recommended.
How often should the pump seals be replaced under typical semi-preparative usage?
With regular use at ≤3000 psi and proper buffer flushing via the self-cleaning function, sapphire/PTFE check valves and fluoropolymer seals typically last 6–12 months. Seal lifetime is extended by avoiding abrupt pressure spikes and maintaining inlet filtration (0.45 µm).