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 21 CFR part 11 guidelines
  • Custom integration into IT-infrastructure
  • Templates allow for efficient programming of eluent recipes
  • Direct input via browser application
STATION 1 | Coriolis Mass Flow Meter

Key Specifications

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


Not all bottles are created equal. It would great to use just Schott bottles to prepare eluents, but their large manufacturing tolerances necessitate a volumetric flask during the manual process. Our FLEX EP bypasses this transfer by calibrating every Schott bottle ad hoc: a Coriolis mass flow meter measures the water flow and adjusts the final volume with high throughput and accuracy.

STATION 1 | 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


In a second step, the liquid level is measured with an ultrasound detector. This value is saved as a reference for a subsequent step, where the final eluent volume will be compensated up to this level.

STATION 2 | Small Volume Liquid Handling

Key Specifications

  • Four ambient pressure syringe pumps
  • PTFE tubing from the syringe pumps to the needles
  • Rinsing station for automatic cleaning of needles and lines
  • 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%


The 4-Needle Head (4-NH) has two functions: it removes water to make space for the eluent’s ingredients and adds other liquid components to the eluent. The 4-NH is resistant to chemicals and designed for precise handling of organic solutions. The self-cleaning routines can be programmed freely.

STATION 2 | pH Measurement and Adjustment

Key Specifications

  • pH range 0…14
  • zero point (pH) 7.00 ± 0.25
  • resolution 0.05
  • temperature range 0…80 °C
  • shaft material glass
  • membrane glass LoT
  • membrane resistance (25°C) < 600 mΩ
  • Temperature probe NTC 30 kΩ


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 | High Throughput Solids Handling

Key Specifications

  • nominal balance accuracy 1 mg
  • number of containers 12
  • storage capacity per container 100 mL
  • total storage volume 1’200 mL


Salts and other powders are dispensed by two gravimetric dispensing units (GDU-P and GDU-Pfd). All solids are stored in GDU-containers, automatically picked up by the GDU and dispensed directly into Schott bottles. The GDU-P is built for fast dispenses of larger quantities while the GDU-Pfd allows for a high accuracy. The system decides autonomously, which balance to use in order to maximize throughput while adhering to the specified accuracy.