Pumps, valves, probes, fittings, tubing and sensing components for precise sample preparation, reagent handling and instrument fluidics.
Syringe Pumps for Automated Sampling and Injection
Application guide · Automated sampling
A syringe-pump sampling channel must collect a defined aliquot, preserve it during transport and hand it to a sample loop, injection valve or reaction vessel. The syringe volume is only one part of the budget: tubing fill, overdraw, air segmentation, probe retention and wash movement also consume stroke.
Engineering example: a 20 μL sample loaded into a 20 μL loop may require more than 20 μL at the probe because the connecting path and the chosen complete-loop filling method also consume sample. State the permitted sample consumption before selecting the syringe; do not infer it from loop size alone.[1][2]
01Define the liquid, receiver and complete duty before selecting the component
Translate the analytical task into an engineering duty
Use case
Inputs to define
Decision supported
Clinical sample to reaction cup
Available serum/plasma/urine, routine dose, minimum liquid level
Keep the sample at the probe end when system-fluid displacement is used
Autosampler to sample loop
Loop size, partial- or complete-fill method and waste destination
Separate low-pressure loading from the high-pressure injection event
Shared sample path
Highest-to-lowest concentration sequence and wash allowance
Include valve, tubing and probe surfaces in carryover testing
02Calculate the working point and the margin the instrument really needs
Calculations to complete before prototype selection
Use minimum, routine and maximum conditions rather than one nominal point. Include the first cycle after priming or idle, the lowest source level, the highest expected restriction and the actual receiving geometry. A nominal capacity, free-flow value or theoretical command increment is not an acceptance result.
03Map the task to a FOREACH configuration and the rest of the fluid path
04Program the full liquid cycle, including prime, wash and recovery
Prime to waste→Approach sample and set depth→Aspirate sample segment→Move through defined valve state→Fill loop or deliver to vessel→Wash and verify recovery
A complete method cycle is more than the active delivery step
The exact physical order and parallel actions depend on the instrument. Retain each state in the control and verification plan.
Record valve states, motion, dwell, sensor windows and rejected recovery cycles. This makes throughput and liquid consumption auditable and prevents a fast component movement from being reported as the complete analyzer cycle.
05Design abnormal-state diagnosis before the fault occurs
Observed result, likely mechanism and useful next action
Observed condition
Likely mechanism
Engineering response
Correct volume but low analyte recovery
Sample/system-liquid interface or adsorption
Shorten the mixed interface, change path material or revise segmentation
Random injection response
Bubble, partial loop fill or unstable aspiration
Inspect bubble/pressure signature and loop-loading method
Only high-to-low sequence fails
Carryover at probe, valve or common tubing
Locate residue with staged wash tests before increasing all wash volumes
The controller should distinguish a recoverable event from a result-invalidating event. A retry is useful only after the original cause has been removed and the liquid path has returned to a verified state.
06Accept performance where the liquid is actually used
Minimum qualification plan for the integrated channel
Result
Where or how to measure
Acceptance question
Received sample volume
Gravimetric or suitable volumetric method at the receiving position
Steady cycles and first cycle after idle
Sample integrity
Applicable tracer or analytical method
No unintended dilution or unacceptable adsorption
Carryover
Worst high-to-low sequence
Project-specific limit at the assay result
Test the exact liquid and complete wetted path at minimum, routine and maximum conditions.
Separate first-cycle, steady-state and post-idle results; do not average away recovery behavior.
Challenge the relevant fault and confirm the controller prevents an invalid result from being accepted.
Retain the configuration, software sequence, consumables and receiving-position result together as the qualification record.
