Abstract: The benefits of automated sample preparation in analytical chemistry are clear but navigating the options that need to be considered and well understood to implement a robust automated process is often not so straight forward.
The presentation will address :
• At the simplest level simply automating an existing manual method with components that are designed for manual processing rather than components optimised for an efficient automated process. Examples of classical approaches to mixing, filtering, extracting, SPE, solid extraction, liquid extraction etc. are often not the preferred when automating and new automated versions of these processes will be demonstrated. • Ideally workflows should be designed to run a whole automated sample preparation process without intervention to permit unattended operation. • Generally, automation cannot replicate the human ability to observe and adjust in the way a sample is handled. For example, it is difficult for automation to assess adequate homogenisation of an individual sample or adjust a needle position when aspirating a supernatant that contains some residue or allow for variations in viscosity of liquids or particles in an SPE process. Processes need to be normalised so that they can occur consistently without a human having to observe and make adjustments. • Automation properly implemented can lead to a level of precision that is impossible by manual processing with liquid volume handling typically achieving 0.2% RSD. Rather than the sample preparation being the weak link in analytical processes, automation of a complex process that includes homogenising, dilution, extraction, filtering and aliquoting it is not unusual to achieve precision in the order of 1 – 2% RSD.
Encompassing a range of different sample types and processes, examples of automated sample preparation workflow development will be presented to demonstrate the above issues.
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