METTLER TOLEDO DispenSix Six-Port Intelligent Liquid Handler

Overview

The METTLER TOLEDO DispenSix Six-Port Intelligent Liquid Handler is a high-precision, modular liquid dispensing system engineered for integration into automated potentiometric titration workflows. Unlike conventional single-channel or fixed-ratio dispensers, the DispenSix employs a dual-actuation dDrive mechanism—combining stepper motor control with pressure-assisted fluid handling—to deliver traceable, gravimetrically validated liquid transfers across six independently addressable ports. Its core function is not standalone titration, but rather intelligent, context-aware reagent and sample delivery synchronized with METTLER TOLEDO’s Titrando or Compact Titrators via RS-232, USB, or Ethernet. This architecture enables true method-driven liquid handling: each port can be assigned a specific solvent, titrant, or standard solution, with volume, sequence, and timing governed by the titration method itself. Designed and manufactured in Switzerland, the system adheres to ISO 8655-3 for piston-type volumetric apparatus, ensuring metrological traceability for volumes from 10 µL to 500 mL. It serves as a critical pre-analytical module in regulated environments where reproducibility, audit readiness, and reagent integrity are non-negotiable.

Key Features

• Six-port architecture supporting concurrent assignment of up to four distinct solvents/titrants—enabling multi-step dilution series, blank correction, and internal standard addition without manual intervention
• dDrive dual-mode actuation: combines high-resolution stepper positioning (1/120,000 step resolution) with dynamic pressure compensation to maintain ±0.42 µL dispensing precision across viscosity ranges typical of aqueous, alcoholic, and low-conductivity organic media
• Integrated RFID-enabled tip and reservoir identification: each consumable carries an embedded tag storing lot number, calibration history, compatibility profile, and expiration data—automatically validated at initialization
• Chemically resistant wetted path constructed from PTFE, ETFE, sapphire, and ceramic components; compatible with aggressive titrants including perchloric acid, silver nitrate, and potassium permanganate
• Tool-free modular disassembly: pipetting head, valve manifold, and fluidic cartridge detach in <30 seconds for cleaning, sterilization (autoclave-safe up to 121°C), or replacement—minimizing downtime during GLP/GMP audits
• Plug-and-play recognition via embedded firmware: automatically detects connected modules (e.g., heated reservoirs, inert gas purging units) and configures I/O mapping without manual setup

Sample Compatibility & Compliance

The DispenSix handles samples and reagents across a broad physicochemical spectrum: aqueous buffers (pH 0–14), non-aqueous titrants (e.g., glacial acetic acid, chlorobenzene), suspensions (e.g., CaCO₃ slurries), and viscous solutions (up to 500 cP). All fluidic contact materials comply with USP Class VI biocompatibility standards and EU Regulation (EC) No. 1935/2004 for food contact. The system supports full traceability per FDA 21 CFR Part 11 through electronic signatures, audit trails for all dispense events (timestamp, operator ID, volume, port, reagent ID), and immutable log archiving. It meets ISO/IEC 17025 requirements for testing laboratories and is validated for use in pharmaceutical QC according to ICH Q2(R2) guidelines for analytical procedure verification.

Software & Data Management

DispenSix operates natively within METTLER TOLEDO’s tiamo™ software suite (v3.5+), enabling synchronized method scripting across titration and dispensing steps. Each dispense action is logged with metadata—including environmental temperature, atmospheric pressure, and syringe wear index—and exported in ASTM E1382-compliant .csv or .xlsx formats. The embedded database stores >10,000 dispensing records with SHA-256 hashing for data integrity verification. Remote diagnostics, firmware updates, and calibration certificate synchronization occur over TLS 1.2-secured connections. Optional integration with LIMS (e.g., LabWare, Thermo Fisher SampleManager) via ASTM E1578-compliant API ensures seamless sample tracking from receipt to report.

Applications

• Automated preparation of multi-point calibration standards for redox, acid-base, and complexometric titrations
• Sequential addition of masking agents (e.g., triethanolamine) and pH buffers in EDTA-based metal ion assays
• High-throughput sample conditioning for ASTM D664 (acid number), D974 (neutralization number), and ISO 8295 (surface tension)
• Reproducible dilution of concentrated stock solutions (e.g., 0.1 M AgNO₃ → 10⁻⁶ M working standards) with certified uncertainty budgets
• On-demand reagent replenishment during long-duration Karl Fischer coulometric titrations to maintain electrolyte stability

FAQ

Does DispenSix perform titration measurements itself?
No. DispenSix is a dedicated liquid handler—not a measuring instrument. It delivers reagents and samples to METTLER TOLEDO potentiometric titrators (e.g., Titrando 907, Compact Titrator) which perform the actual potential measurement and endpoint detection.
Can DispenSix be used with non-METTLER TOLEDO titrators?
Yes, via custom ASCII command protocol over RS-232 or TCP/IP, provided the host instrument supports external trigger inputs and volume acknowledgment feedback.
What validation documentation is supplied?
Each unit ships with a Factory Calibration Certificate (traceable to NIST SRM 3109a), ISO 8655-3 conformity statement, and IQ/OQ templates compliant with Annex 11 and GAMP 5.
Is preventive maintenance required?
Yes. Annual PM includes syringe plunger torque verification, valve seat wear inspection, and RFID tag integrity validation—performed by METTLER TOLEDO Field Service Engineers with full service history logging.
How is carryover controlled during sequential dispensing?
The system implements programmable air-gap aspiration, post-dispense purge cycles (adjustable 0–50 mL/min N₂ flow), and real-time conductivity monitoring of wash lines to confirm residue removal before next use.