FLEX EP - Fully automated system for the preparation of eluents under GxP!


Compliance-ready workstation, seamlessly integrated with your lab information management system.

Explore the possibilities to automate lab work and digitalize your audit trail - fully compliant with FDA 21 CFR part 11 and GAMP 5.

FLEX EP | Technical Layout

1. Large volume liquid handler Coriolis mass flow meter Ultrasound detector
2. Small volume liquid handler pH-adjustment
3. Large volume solids handler
4. Small volume solids handler
5. Screw-capper
6. Thermo-transfer labeler

FLEX EP | Workflow
  • Compliant with FDA’s 21 CFR part 11 guidelines
  • Custom integration into IT-infrastructure
  • Full transparency and control over experimental parameters
  • Templates allow for efficient programming of eluent recipes
  • Direct input via browser
STATION 1 | Printer & Labeler

Key Specifications

  • print technology Thermal transfer
  • print resolution up to 600 dpi
  • printing speed 400 mm/s
  • print width 100 mm
  • label width 114 mm


All bottles are labeled with readable text and QR-code. The print is solvent resistant, layout and content can be freely programmed to fit your requirements.

STATION 2 | Coriolis Mass Flow Meter

Key Specifications

  • flowrate up to 1000 mL / min
  • volumetric range 10…2000 mL
  • accuracy ± 0.6%
  • precision ± 0.3%


Schott bottles are generally used to store eluents for liquid chromatography, but the manufacturing tolerances are too large to use them for the preparation. The FLEX EP bypasses the need for volumetric flasks by calibrating every single Schott bottle ad hoc: a Coriolis mass flow meter measures the water flow and adjusts the final volume with highest throughput and accuracy.

STATION 2 | Surface Level Detection

Key Specifications

  • distance range 60…400 mm
  • accuracy ± 0.5 mm
  • precision ± 0.3 mm
  • response time < 60 ms
  • sound frequency 400 kHZ


Once filled to the target volume, the liquid level in the Schott bottle is measured with an ultrasonic proximity sensor. This value is used in a subsequent step to compensate the liquid level back to the target volume.

STATION 3 | Small Volume Liquid Handling

Key Specifications

  • four independent septum-piercing steel needles
    • inner diameter 0.8 mm
    • length 292 mm
  • volumetric range 2.5…10 mL
    • accuracy ± 0.8%
    • precision ± 0.3%
  • volumetric range 10…100 mL
    • accuracy ± 0.6%
    • precision ± 0.3%
  • four ambient pressure syringe pumps
  • PTFE tubing from the syringe pumps to the needles
  • rinsing station for automatic cleaning of needles and lines


The pH can be measured and adjusted if needed.  Calibration of the analytical sensor is carried out automatically in defined time intervals. Pre-filled bottles with acids and bases are stored inside the system.

STATION 3 | pH Measurement and Adjustment

Key Specifications

  • accuracy of pH-electrode 0.01
  • accuracy of verification 0.05
  • measuring range 0…12
  • temperature sensor PT1000
  • temperature range 0…80 °C
  • electrolyte saturated KCl gel
  • reference system Ag/AgCl with Ag scavenger
  • shaft material glass
  • membrane HT glass


The pH can be measured according to USP <791> and adjusted if needed. Calibration of the analytical sensor is carried out automatically in daily intervals. Pre-filled bottles with acids and bases are stored inside the system.