Automatic instruments

Automatic instruments relieve the analyst from several operations. The precise nature of automatic operations improves the precision. 

Automatic instruments, as mentioned before, are not feedback control devices but rather are designed to automate one or more steps in an analysis. They are generally intended to analyze multiple samples, either for a single analyte or for several analytes. 

Automatic instruments will perform one or more of the following operations  

Sample pickup (e.g., from a small cup on a turntable or assembly fine) 

Processing of the data (correct for blanks, correct for nonlinear cahbration curves, calculate averages or precisions, correlate with the sample number, etc.). 

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The realization of sensitive bioanalytical methods for measuring dmg and metaboUte concentrations in plasma and other biological fluids (see Automatic INSTRUMENTATION BlosENSORs) and the development of biocompatible polymers that can be tailor made with a wide range of predictable physical properties (see Prosthetic and biomedical devices) have revolutionized the development of pharmaceuticals (qv). Such bioanalytical techniques permit the characterization of pharmacokinetics, ie, the fate of a dmg in the plasma and body as a function of time. The pharmacokinetics of a dmg encompass absorption from the physiological site, distribution to the various compartments of the body, metaboHsm (if any), and excretion from the body (ADME). Clearance is the rate of removal of a dmg from the body and is the sum of all rates of clearance including metaboHsm, elimination, and excretion. 

The concentration of fuel in air in a process should be maintained at or below 25 percent of the LFL, with automatic instrumentation and safety interlocks however, up to 60 percent of LFL is permitted by the NFPA—except for ovens or furnaces. (Ovens and furnaces are covered in NFPA 86.)... 

Discuss the use of data telemetered to the office of the air pollution control agency from automatic instruments measuring ambient air quality and automatic instruments measuring pollutant emissions to the atmosphere as air pollution control regulatory means. 

Critical temperatures throughout the tower are controlled by automatic instruments and products are withdrawn under various combinations of flow and level control. A pipe still is capable of mnning for days on end with only minor adjustment by the operators except, of course, when a change in crude type or in product distribution is required. 

When automatic instrumentation with safety interlocks is provided, the combustible concentration may be maintained at or below 60% of the LFL. 

Temperature Control (Manual) (Automatic). Instruments Controls (Weather Protected) (Explosion ProoO Level Controls - To Be Pressure Gauges To Be Condenser Cooling Water ... 

Automatic instruments are usually reflection-type instruments that measure the deflection of a beam of light as it passes from one medium, into the sample and then is reflected back to a detector. The angle at which the light beam exits the medium is related to the refractive index of the sample. Automated instruments are calibrated with standard substances of precisely known refractive index prior to use. 

The most important application of the valinomycin macroelectrode is for the determination of potassium in serum [9, 126,141,174] and in whole blood [45, 71, 224]. This electrode with a polymeric membrane is a component of most automatic instruments for analysis of electrolytes in the serum. It has also been used for monitoring the K level during heart surgery [168]. The valinomycin ISE is also useful for determination of Rb [33]. 

Analytical procedure is a systems problem and the samphng, pretreatment, measurement, data collection and reduction, and final reporting all have to be considered in a fiilly automatic approach. Computerization is often considered to he synonymous with automation but, although microprocessor technology is certainly changing the face of automatic instrumentation and influences both the control aspects and the data reduction, computerization is only a part of automation. Computers should simply be considered as tools of the trade within the area of automation. 

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. 

Few books attempt to cover the area of automatic chemistry. Technical papers which relate to automation have most often been presented in analytical journals dealing with the basic subject area, and the details of the automation are less well documented than the chemistry. Aspects of management, education and economics are given scant treatment despite their importance. The Journal oj Automatic Chemistry [8] was launched to fill this void in the literature and experience has shown that there is a wealth of technical experience awaiting publication. In addition, it is vital for the suppliers of automatic instrumentation and computer systems to set up adequate lines of communications with their customers. User groups are a valuable asset so that experiences, good and bad, are shared and any problems resolved. A user who becomes frustrated for lack of support or information will become a source of bad reference. A satisfied user, on the other hand, will provide valuable input which may benefit future users and assist the company in providing instruments that the user needs. 

Besides understanding the philosophy and concepts of automatic instrumentation, it is necessary to make a clear economic assessment of the advantages to he gained from the introduction of automation. There can he no substitute for practical experience in solving such problems. The field is wide, so a complete review is not practical. Some developments are described here to stimulate the reader into deeper research. It is important to evaluate the various developments that have become available through both large and small instrumentation companies. 

In an automatic instrument developed by Lidzey and Stockwell [19] for the analysis of ftirftiraldehyde in gas oil, a preliminary separation is performed on a GC column coupled to a specific colorimetric reagent in a continuously flowing hquid stream. A back-flushing... 

A specification for such an automatic instrument can be summarized as follows ... 

A simple and more direct method, which involves the use of a primary gas-chromatographic separation combined with a specific colorimetric device, was evaluated against the standard manual technique and proved sufficiently rehahle to form the basic design for a routine automatic instrument. 

Silent-hours operation, which is commonly termed hands-off analysis, requires the automatic analysis to operate to a set protocol. For a fully automatic instrument to run in this manner, it will require a feedback system comparing the results with check cahbration standards. A calibration graph can be constructed from the analytical data, and the precision of this graph is easily evaluated. As the analyses proceed, the system can be monitored by reference to the check calibration standards. Should the performance remain within specification, the analyses can safely go on. The automatic instrument can then operate within the set protocols throughout the silent hours, taking full account of any variations in the instrument and its operating parameters. 

Table 1.2 gives some of the reasons for the LGC setting up its automation team. The primary motivation was economic. LGC was often subject to constraints on staffing in parallel with large increases in analytical commitments. The introduction of cost-effective analyses, using mechanical or automatic instruments, reduces staff involvement and allows well qualified people to be released for the development of new analytical requirements. The analysis of beer samples by multi-channel continuous flow analyser [S, 6, 7] and the introduction of a mechanical solvent extraction and identification system to analyse and measure levels of quinizarin in gas oil, both for duty purposes, were prime examples [8], Both systems involved commercially available components and/or instruments integrated with modules designed and built in-house. 

Defining the specification of the analytical requirement and its solution are difficult and the analytical chemist s experience is vital. Only he or she can accurately predict the ruggedness or vagueness of analytical procedures. Customers know how they would like the automatic instrument to operate and will have a good understanding of the chemistry involved. How a specification should be drawn up is explained in Chapter 2, but unless it is carried out properly the equipment will be over- or under specified or if the problem is not correctly addressed, the automatic equipment will fall into disuse because it fails to achieve the overall objective. 

The ammonium extracted by the potassium chloride reagent is analysed by steam distillation. This may be carried out using an automatic instrument such as the Kjeltec Auto 1035 Analyzer (USDA, 1996, pp. 203-210), or a micro (or semi-micro) steam distillation unit such as that described by Bremner and Keeney (1965), or the readily available Markham still. We will describe the manual procedure. 

Examples include the development of more sensitive and reliable automatic instrumentation for monitoring chemicals, radiation and biological materials in the environment, of safety-or-environment-related add-on equipment for vehicles, of pollution-control technology and of safety-related equipment for use in industry, mining and the home. 

Other automatic instruments do not require the sample to be inserted between two prisms. These require the sample to be placed on a glass surface, and detection is of the critical reflection internal to the glass. In this type of instrument, the detection is electronic, and temperature compensation can be programmed into the operational procedure. 

Other Methods. Marion et al. used a competitive ELISA to measure the specificity of anti-DNA antibodies. Low-affinity, low-avidity antibodies bind to competitor DNAs in solution and thus cannot bind to solid-phase DNA subsequently (M7). A new automatic instrument platform using the immunofluorescence method (EliA ) to detect anti-dsDNA has recently been developed. We found that results from this method correlated well with results from the ELISA method (unpublished). 

The simplest air quality monitors are static sensors, which are left in the area being monitored for some length of time and are later analyzed in a laboratory. More commonly, automatic instruments are used that measure several air quality parameters and either retain the collected data on magnetic tape or transmit it by wireless transmission. 

Shikata, Masuzo — (Aug. 10,1895, Tokyo, Japan - May 8, 1964, Kyoto, Japan) In 1920 Shikata graduated from the Department of Agricultural Chemistry of the Imperial University of Tokyo. In 1922 he went to Europe, and the next year joined - Heyrovsky, J. in Prague, Czechoslovakia. In 1924 Heyrovsky and Shikata [i] developed the first - polarograph - the first automatic instrument to record current-potential dependencies of a - dropping mercury electrode. For this invention, Heyrovsky was awarded the Nobel Prize in Chemistry in 1959. In 1924 Shikata was appointed Professor of the Imperial University of Kyoto (presently Kyoto University). In 1942 he was appointed Vice-President of the Research Institute of... 

The interest in LIMS is directly due to the need to manage the increasing amounts of data generated by the modern analytical laboratory. LIMS systems are used in quality control and analytical services laboratories within the petroleum, petrochemical, chemical, pharmaceutical industries and others, where intelligent, automatic instruments generate large amounts of data. The laboratory must process, correlate, report and store these data securely for long periods of time. 

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