Where automated dilution fits in the instrument
Determine ratios for samples, stock and diluent from actual delivered volumes. Shared-section residue, mixing and volume error jointly affect final concentration. Assess using blanks, ratio checks or spike recovery.
Sample and diluent errors, shared-section residue and mixing all affect final concentration. After assessing delivered volume, check the ratio, spiking result or method response.
Product responsibilities in this operation
Syringe drive and valve positions jointly organize aspiration, holding and dispensing. Record working volume, remaining inventory and replenishment timing according to the sequence.
For analytical sample preparation, define actual sample, diluent or internal-standard volumes, concentrations at each stage, mixing and subsequent sampling conditions.
Organize the sequence by actual architecture
- Identify the original sample, diluent and method-required additives. Record source identities, target ratios, preparation relationships between levels and final receiving location.
- In the syringe-driven fixed path, check each source and actual working volume separately, clear shared-section residue, then complete delivery from each path.
- Complete mixing for the actual container and method, then measure the received ratio and required concentration or response. Subsequent sampling must follow completed mixing.
- Assess the complete preparation using blanks, ratio checks or spike recovery, covering small doses, source switches and the first sample after maintenance. Investigate volume errors and analyte losses separately.
Define operating conditions for this task
| To define | Details |
|---|---|
| Actual operating conditions | Actual volumes of original sample, diluent or internal standard; concentrations at each stage; mixing and resampling conditions |
| Acceptance target | Measure each sample, stock, diluent or method-required additive at the receiving vessel. Verify the combined ratio and mixing before taking the next aliquot, including the smallest doses and source changes. |
| Fault localization | A missing addition, shared-path residue or incomplete mixing can change the prepared concentration. Later dilution levels can inherit that error even when their own commanded volumes are correct. |
Compare product configurations by the roles on this page
| Product | Configuration option | Conditions to verify |
|---|---|---|
| HLD rotary-valve syringe pump | Aspiration, holding and dispensing with a rotary valve | Check source/outlet valve positions, capacity budget and replenishment timing |
| HMD solenoid-valve syringe pump | Metered aspiration and dispensing with solenoid valves | Check open/closed and power-off states, working volume and replenishment cycle |
Validate operation results at the receiver
Measure each sample, stock, diluent or method-required additive at the receiving vessel. Verify the combined ratio and mixing before taking the next aliquot, including the smallest doses and source changes.
Check concentration or method response with the specified blanks, ratio checks or spike-recovery procedure. Investigate a correct volume with poor analyte recovery separately from a dosing error.
Locate abnormalities and restore the next operation
A missing addition, shared-path residue or incomplete mixing can change the prepared concentration. Later dilution levels can inherit that error even when their own commanded volumes are correct.
Identify the affected preparation level and any aliquots already taken from it. Reconcile completed additions and mixing, restore the relevant source path, then remake or handle the affected preparation and downstream levels according to the method.
Accepted delivered volume is only part of dilution validation. The prepared composition, mixing and analyte recovery must meet the analytical method.