Optical instruments, automation

Although iastmmentation is discussed ia many of the analytical articles, there are only a few places ia the Eniyclopedia where it is the primary emphasis (see Analytical methods, hyphenated instruments Automated instrumentation). However, articles relating to materials used either ia or as iastmmeatal compoaeats such as eaergy sources (see Lasers), sampling devices (see Eiber optics), and detectors (see Biosensors Photodetectors SsENSORs) abound. 

The previous section described the reduction of human intervention in the operation of an optical instrument In order to facilitate or make poesible Its functioning. Another aspect of great Interest In this context is the automation of the acquisition and treatment of data from an Instrument based on measurements of an optical nature, understandably the earliest to be developed on account of Its great simplicity. 

The technology of integrated optics (Chap. 2, Sect. 2.3.4) is a branch of microoptics, which emerged from the successful techniques of microelectronics together with micromechanics and other microtechnologies. The processes of integrated optics allow one to fabricate complete optical instruments like spectrometers, refractometers etc. in strongly miniaturized form and are extremely cost efficient, since fully automated mass production is common for this industry. 

Figure 10 Raman spectra of various mixtures of nitrogen and oxygen obtained with the spectrograph in Figure 9. For the sake of clarity the spectra have been vertically displaced from one another. The N2 peak is on the right. Band intensity is essentially from the pure vibrational mode. The rotational-vibrational side bands form weak overlapped wings on either side of the main peaks. Reproduced with permission of the Society of Photo-Optical Instrumentation Engineers (SPIE) from Gilbert AS, Hobbs KW, Reeves AH and Jobson PP (1994) Automated headspace analysis for quality assurance of pharmaceutical vials by laser Raman spectroscopy. Proceedings of the SPIE - Society of Photo-Optical Instrumentation Engineers 2248 391-398.

A further unit developed for assessment of dispersion, particularly for weatherstrip extrusion compounds where siuface finish is very important, is a combined small extruder and surface roughness analysis system. This is a joint development between a mixer manufacturer and an optical instrumentation company (a. 14). Developed further with the fitting of a rheometer die, rather than a strip die, the extruder can be instrumented to give rheological information on the compoimd. An automated method that gives information on shear viscosity at two different flow rates has been developed. 

The biberty (Fig. 10), a monomode microwave reactor for automated SPPS, was recently introduced by the CEM Corporation [153]. Although this instrument was originally developed for SPPS, it also allows for a broader scale of solid-phase applications. The solid-phase vial is equipped with a polypropylene frit and cap at one end (the entire assembly fitting into the standard 10 mb CEM reaction vessel) to allow the processing of 0.1 to 1.0 mmol quantities of resin attached substrates. An integrated fiber optic probe provides... 

Other analyzers such as the Gilford Automated Enzyme Analyzer and the LKB-8600 Reaction Rate Analyzer analyze discrete samples one at a time. These instruments provide kinetic analyses, digital data reduction at the time each sample is analyzed, and excellent electronic and optical characteristics. Recently, Atwood has developed kinetic enzyme analyzers which require only 9 seconds for measuring an enzyme activity, using highly stable and sensitive electronic circuits (12). This short read out time allows a large number of samples to be processed by one instrument in an automated mode. 

Wherever possible, analytical systems are automated and directly interfaced to a laboratory data system. This mainly receives information from an Optical Mark Registration (OMR) system, or from down loaded computer files, and then produces a work schedule which is printed for the analyst and transferred electronically to the instrument. 

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