How does automated sample preparation work?

Automated sample preparation works by using programmable instruments to carry out the extraction, cleanup, and concentration of laboratory samples without manual intervention at each step. The system moves samples through a defined sequence of operations, including solvent extraction, solid phase extraction, and evaporation, producing purified extracts ready for instrumental analysis. The sections below unpack each stage of the process, explain how automation compares to manual methods, and help laboratories decide when the switch makes sense.

What steps are involved in automated sample preparation?

Automated sample preparation typically follows four core steps: extraction, where target compounds are separated from the sample matrix; cleanup, where interfering substances are removed; concentration, where the extract volume is reduced to meet instrument requirements; and transfer, where the final extract is delivered to the analytical instrument. Each step runs sequentially under instrument control, with minimal analyst involvement.

The exact sequence depends on the sample type and the contaminants being analyzed, but the logic remains consistent across applications. For environmental contaminant analysis, a typical workflow looks like this:

Homogenization and weighing: The sample is prepared, and a defined portion is loaded onto the system.
Solvent extraction: The system applies a solvent or solvent mixture to dissolve the target analytes from the matrix. Systems based on the Randall principle, for example, perform extraction directly in boiling solvent, followed by a hot Soxhlet or Twisselmann step to maximize recovery.
Solid phase extraction (SPE): The crude extract passes through one or more SPE cartridges or disks, which selectively retain or release the target compounds while trapping matrix interferences.
Concentration and evaporation: The purified extract is reduced to a precise end volume using vacuum centrifugation, nitrogen evaporation, or parallel evaporation systems.
Fraction collection and transfer: The system collects defined fractions at set volumes and delivers them to labeled vials ready for GC or LC-MS injection.

Modern automated sample preparation systems can handle multiple samples in parallel, running consecutive sequences without analyst oversight between batches. This makes the workflow far more reproducible than any manual approach, because every sample passes through identical conditions.

How does automated sample cleanup remove contaminants?

Automated sample cleanup removes contaminants by passing the crude extract through sorbent-packed cartridges or disks in a controlled, reproducible sequence. The sorbent selectively retains either the target analytes or the matrix interferences depending on the cleanup strategy, allowing the system to elute a purified fraction. Lipids, pigments, sulfur compounds, and co-extracted organic matter are the most common interferences removed during this stage.

Solid phase extraction is the dominant cleanup technique in automated systems. The SPE cartridge contains a sorbent chosen to match the chemical properties of both the target analytes and the matrix. In dioxin and PCB analysis, for example, multi-layer column cleanup using activated carbon, silica, and alumina phases is standard, because these sorbents separate persistent organic pollutants from co-extracted lipids with high selectivity.

Automated cleanup systems control every parameter that affects separation quality: flow rate, elution volume, back-pressure, and fraction collection timing. Because these variables are locked into the instrument method, the cleanup result is consistent across every sample in a batch. In contrast, manual column cleanup introduces variability each time an analyst adjusts the flow by hand or misjudges the fraction endpoint.

For large-volume water samples, automated disk-based systems use 25 mm, 47 mm, or 90 mm extraction disks with online filtration and water removal, eliminating the manual steps that would otherwise introduce contamination or analyte loss. The result is a cleanup process that is both faster and more reliable than its manual equivalent.

What types of samples can automated systems process?

Automated sample preparation systems can process a wide range of matrices, including food, feed, soil, sewage sludge, water, air, biological tissue, and industrial materials. The key factor determining compatibility is whether the system’s hardware, sorbents, and solvent handling are configured for the physical and chemical properties of the matrix in question.

Solid and semi-solid samples such as soil, feed, and fatty food products require an initial extraction step to transfer target analytes into a liquid phase before cleanup can begin. Liquid samples such as drinking water, surface water, and wastewater can be loaded directly onto SPE cartridges or disks, making their preparation workflow shorter.

In environmental contaminant analysis, the most commonly processed matrices include:

Food and feed: Fatty matrices such as fish, meat, and dairy require lipid removal during cleanup before dioxin or PCB analysis.
Soil and sediment: High organic matter content demands robust extraction conditions and multi-step cleanup.
Water: Large volumes, often up to 1,000 mL or more, are processed using high-capacity SPE disks or cartridges designed for PFAS, pesticides, hormones, and other emerging contaminants.
Sewage sludge and biological sludge: These matrices combine high water content with complex organic loads, requiring systems capable of handling both extraction and extensive cleanup.
Air samples: Collected on filters or adsorbent tubes, air samples are extracted and purified for dioxin and PBDE analysis.

The versatility of modern automated platforms means that a single laboratory can configure one system to handle multiple matrix types by switching cartridge formats, disk sizes, or solvent programs, rather than investing in separate equipment for each application.

How does automation reduce solvent use in sample preparation?

Automation reduces solvent use in sample preparation by precisely controlling flow rates, elution volumes, and solvent delivery, eliminating the overuse that is common in manual methods. Automated systems dispense only the volume required for each step, and many modern platforms are specifically engineered to complete full extraction and cleanup cycles using less than 100 mL of organic solvent per sample.

In manual sample preparation, analysts typically use excess solvent to ensure complete extraction or elution, because the consequences of under-eluting are more visible than the cost of using extra solvent. Automated systems remove this incentive by making the optimal volume a fixed instrument parameter rather than an analyst judgment call.

Solvent reduction in automated systems is achieved through several design features:

Closed-loop solvent delivery: Solvents are dispensed from sealed reservoirs through inert flow paths, reducing evaporative losses and eliminating the need for open containers.
Solvent recovery: Systems such as the SER-158 extractor collect solvents in a recovery tank during extraction, reducing total consumption and waste disposal costs.
Optimized elution volumes: SPE methods are programmed with the minimum elution volume validated during method development, rather than a conservative manual estimate.
Elimination of dichloromethane: Several modern automated platforms operate entirely without dichloromethane, replacing it with less hazardous solvents that are safer for laboratory staff and the environment.

The environmental and financial benefits compound quickly at scale. A laboratory running hundreds of samples per month can reduce its solvent purchasing and waste disposal costs substantially by switching to an automated workflow with controlled solvent delivery.

What is the difference between automated and manual sample preparation?

The core difference between automated and manual sample preparation is reproducibility. In a manual workflow, every step, including solvent volumes, flow rates, timing, and fraction collection, depends on the analyst performing the work. In an automated workflow, those parameters are fixed in an instrument method and executed identically for every sample. This difference directly affects data quality, throughput, and laboratory risk.

Beyond reproducibility, several practical differences distinguish the two approaches:

Throughput: Automated systems can process multiple samples simultaneously or in consecutive sequences. A system processing 8 samples per sequence across 10 consecutive runs handles 80 samples in a single unattended run. Manual preparation of the same number of samples would require continuous analyst time across multiple working days.
Analyst exposure: Manual extraction and cleanup expose analysts to organic solvents, toxic matrix components, and persistent pollutants. Automated systems enclose the process, significantly reducing occupational exposure.
Cross-contamination risk: In automated systems where samples do not come into direct contact with the instrument hardware, cross-contamination between samples is eliminated. Manual methods rely on thorough cleaning between samples, which introduces human error.
Traceability: Automated systems log every parameter for every sample run, creating an audit trail that supports accreditation requirements under ISO 17025. Manual records depend on analyst note-taking.
Upfront investment: Automated systems require a higher initial capital outlay than manual glassware and columns. However, the reduction in analyst time, solvent costs, repeat analyses, and failed QC results typically offsets this cost within a predictable timeframe.

For laboratories working under accreditation or regulatory reporting requirements, the reproducibility and traceability advantages of automation are not optional extras. They are fundamental to maintaining data integrity across a high sample volume.

When should a laboratory switch to automated sample preparation?

A laboratory should consider switching to automated sample preparation when manual throughput has become a bottleneck, when reproducibility issues are affecting data quality, or when analyst time spent on repetitive extraction and cleanup tasks is limiting the laboratory’s capacity to take on new work. Regulatory pressure and sustainability targets are additional drivers that are accelerating the transition in 2026.

There is no single threshold that triggers the switch, but several conditions consistently indicate that automation will deliver a clear return:

The laboratory processes more than 20 to 30 samples per week requiring multi-step cleanup for persistent organic pollutants, PFAS, or pesticides.
Inter-analyst variability is producing inconsistent recovery rates or elevated QC failure rates.
Analysts are spending the majority of their working time on extraction and cleanup rather than on data review, method development, or client communication.
The laboratory is seeking or maintaining ISO 17025 accreditation, where documented reproducibility is a core requirement.
Solvent consumption and waste disposal costs are a significant operational expense, and the laboratory has sustainability commitments to meet.
New contaminant classes such as PFAS are being added to the analytical scope, and existing manual methods are not optimized for these analytes.

Smaller laboratories sometimes delay the switch because they assume automation is only justified at high volumes. In practice, the reproducibility and analyst time benefits are relevant even at moderate throughput, particularly when the samples being analyzed are complex matrices or when the analytical method involves multiple cleanup steps.

How DSP-Systems helps with automated sample preparation

DSP-Systems supplies and configures automated sample preparation and cleanup systems for laboratories analyzing environmental contaminants across Europe and North America. Their portfolio covers the full sample preparation workflow, from extraction to cleanup to concentration:

GO-EHT systems for fully automated purification of dioxins, PCBs, PBDEs, and PCNs across food, feed, soil, water, and air matrices, using less than 100 mL of solvent per sample and no dichloromethane.
SPE2000 for high-throughput solid phase extraction of PFAS, pesticides, hormones, SVOCs, and PAHs, processing up to 80 samples per run across cartridge sizes from 1 mL to 12 mL.
AutoEmpore for large-volume water sample extraction using disk-based SPE with automatic online filtration and water removal.
SER-158 for solvent extraction of solid and semi-solid samples with integrated solvent recovery and concentration.
MultiVap and CentriVap systems for parallel evaporation and concentration to precise end volumes ready for GC or LC-MS injection.

DSP-Systems also provides pre-installation programming, SPE application testing, and configuration in line with EPA and CEN standards, so laboratories receive a validated, ready-to-use workflow rather than a product that requires extensive in-house method development. If you want to discuss which sample preparation solution fits your laboratory’s matrices and analytical scope, contact DSP-Systems directly to speak with a specialist.