Automated and Semi-Automated Sample Prep
Liquid and gas chromatography systems are used in a wide range of research and production processes, including those in pharmaceutical, biotech, food and beverage and environmental areas. When there are large quantities of samples to be dealt with, there are substantial benefits to be obtained by automating or at least partially automating as much of the sample preparation process as possible. Chromatography itself can be used as an automated sample preparation procedure for sample purification in drug discovery. Automating solid phase extraction (SPE) is also increasingly useful for rapid sample prep and purification for chromatographic or other analyses. SPE is a chromatographic separation technique used to remove solid or semi-solid compounds from a mixture in solution. Numerous automated SPE equipment and methodologies for specific LC applications have been developed and used in the past decade, such as the Dionex AutoTrace 280 SPE instrument. This system features automated sample loading of liquids onto SPE cartridges and automated eluting of SPE cartridges with organic solvent. Other common methods for sample prep for LC applications include centrifugation and liquid-liquid extraction.
Systems from multiple suppliers also exist for automating peripheral operations such as automated decapping and recapping of sample vials, automated crimping of crimped-cap vials, automated dry-down, specialized mixing and heating operations, autosampler loading and unloading of racks and platforms, re-dissolution, adding organic solvents and reagents, and more.
Last year, researchers at EMD Millipore introduced Samplicity Filtration System for improving routine sample prep operations. This product provides a high throughput, ergonomic alternative to syringe-tip filters for LC sample prep. It’s the first vacuum-driven device with the flexibility to filter one to eight samples in seconds, including samples with high viscosity or high particulate levels. In addition, it has a low hold-up volume, which allows the processing of samples as small as 300 µL with high recoveries.
The Digiflex Dispenser Diluter from Titertek-Berthold is a semi-automated liquid handler suited for easy sample preparation. This device has intuitive on-board software that allows for easy programming of sample transfer, serial dilutions, volumetric titrations, dispensing and pipetting. It prevents repetitive motion injuries associated with pipetting—a common problem in non-automated sample prep—and frees the operator’s hands. The device’s accuracy and precision in 500 nL to 9,500 µL ensures that the same device can be used for both analytical sample prep and bulk dispensing.