Automation approaches robotic instrumentation

Three approaches to the automation process can be distinguished, taking into account the criterion of the flexibility of the automation device [2], The first, denoted as flexible, is characterized by the possibility of adaptation of the instruments to new and varying demands required from the laboratory examples of these instruments are robots. The second approach, denoted as semiflexible, involves some restrictions for the tasks executed by the instrument the tasks are controlled by a computer program and its menu. As examples, autosamplers or robots of limited moves can be given. In the third approach, the instruments can execute one or two tasks, without feasibility of new requirements as examples, supercritical fluid extractors or equipment for dissolution of samples can be given. 

In addition to semiautomated systems, several fully automated random-access instrumentation have been developed, which enable a high sample throughput. Both for homogeneous and heterogeneous assays equipments have been developed, whereby for the latter approach frequently magnetic particles are used as carriers. Such random-access instrumentation allows the application of individual analyte and assay types. In addition to instrumentation for FIAs, automate instrumentation for CLIAs are also available. Of course, since such fully automated systems involve roboting operations, they are rather expensive. 

There are signs that companies are becoming increasingly aware of the industrial market and some attempts have been made to develop a systematic approach to this problem. Whereas in chnical chemistry the matrix is usually blood or urine, in the industrial area there are many varied matrices. The volume of sales for any matrix is often insufficient to justify the development investment required. An alternative philosophy is needed to meet the requirements economically. The Mettler range of automatic instruments provides one example of a systematic approach to automate a range of analysers. More recently the Zymark Corporation (Zymark Center, Hopkinton, Massachusetts, USA), in the introduction of its Benchmate products, has defined procedures which can be tailored to individual laboratory needs by using essentially similar modules. These modules are coordinated with a simphfled robotic arm. Several tailor-made systems have been developed which have a wide appeal and are easily configurable to particular needs. 

Workstations and robotic systems are very expensive, so inexpensive alternatives such as flow configurations have been developed for automated sample preparation. The earliest flow systems for sample preparation were used for GC determination (with flame ionization detector [FID] or electron capture detector [EGD] detection) of organic compounds, which requires no special extraction or derivatization, in environmental matrices [30-34]. Automated GC-MS systems for the determination of volatiles in water or air [35-38] are the most commonly reported. Detailed descriptions of these systems can be found elsewhere in this book. Few continuous flow systems (CFSs) for the automated pretreatment of biological fluids in combination with GC-MS have been developed to date. The intrinsically discrete nature of the GC-MS sample introduction mechanism makes online coupling to continuous flow systems theoretically incompatible for reasons such as the different types of fluids used (liquid and gas) and the fact that the chromatographic column affords volumes of only 1 to 2 j,l of cleaned-up extract. Therefore, the organic extracts from CFSs have traditionally been collected in glass vials and aliquots for manual transfer to the GC-MS instrument (off-line approach) only in a few cases is an appropriate interface used to link the CFS to the GC-MS instrument (on-line approach). These are the topics dealt with below. 

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