Instrument automation systems

A fully-automated lab may need to contain both types of systems. For instrument automation systems it is important to note that not all instruments (and experiments) can or should be interfaced to a computer. There are some whose accuracy or utility can be impaired by adding an interface. With some instruments there is also the problem of having to go inside the device to gain access to an analog signal, that could void any equipment warranty. One of the choices you may have to face is the early obsolescence of equipment due to the need for easier, and supported, computer-to-instrument interfacing. 

From the physical point of view, the most important considerations are temperature, pressure, and sample cleanness. Suspended solids in liquid samples and dust in gas samples often interfere with transducers in continuous-sampling instruments and with the volumetric sampling techniques used in batch-sampling instruments. Automated systems that filter out solids should be amenable to automatic cleaning. In continuous instnunents, data output must be interrupted while the filters are cleaned in batch-sampling systems, filters can be cleaned during the deadtime after a sample has been injected for analysis. 

In the direct insertion technique, the sample (liquid or powder) is inserted into the plasma in a graphite, tantalum, or tungsten probe. If the sample is a liquid, the probe is raised to a location just below the bottom of the plasma, until it is dry. Then the probe is moved upward into the plasma. Emission intensities must be measured with time resolution because the signal is transient and its time dependence is element dependent, due to selective volatilization of the sample. The intensity-time behavior depends on the sample, probe material, and the shape and location of the probe. The main limitations of this technique are a time-dependent background and sample heterogeneity-limited precision. Currently, no commercial instruments using direct sample insertion are available, although both manual and h ly automated systems have been described. ... 

In principle, on-line SPE-LC can be automated quite easily as well, for instance, by using Such programmable on-line SPE instrumentation as the Prospekt (Spark Holland) or the OSP-2 (Merck) which have the capability to switch to a fresh disposable pre-column for every sample. Several relevant applications in the biomedical field have been described in which these devices have been used. Eor example, a fully automated system comprising an autosampler, a Prospekt and an LC with a UV... 

The computer has become an accepted part of our daily lives. Computer applications in applied polymer science now are focussing on modelling, simulation, robotics, and expert systems rather than on the traditional subject of laboratory instrument automation and data reduction. The availability of inexpensive computing power and of package software for many applications has allowed the scientist to develop sophisticated applications in many areas without the need for extensive program development. 

The minicomputer based system for Instrument automation at Glidden has been prevlousj.y reported (1). since that system predates the availability of low cost personal computers and data acquisition hardware, most of the hardware and software was designed and assembled in-house. ... 

The most complex automated systems are used almost exclusively by centralized HTS operations in large pharmaceutical companies and are referred to as ultra HTS (uHTS) platforms. They typically consist of the same four functional instruments, but have the capacity to process several hundred plates per extended workday. They often incorporate a modular design philosophy with multiple duplicate instruments for enhanced capacity that offer some functional redundancy. The mechanism for moving plates from one instrument module to another is often, but not always, a continuous track-way that resembles an industrial assembly line rather than the robotic arm typically used in a workcell system [5-8],... 

It is interesting to trace the development of instrument automation over the relatively brief period of the past ten to fifteen years. Early in this period, a truly automated instrument was a rare and expensive item built around a costly dedicated minicomputer. Automated data collection and analysis from any instrument which was not automated at the factory was usually accomplished by digitizing the data and storing it on a transportable media such as paper tape. These data were then delivered and fed to a timeshare system of some sort on which the data reduction program ran and which printed a report and sometimes a plot of the data. Often a considerable time delay occured between the generation and the analysis of the data. The scientist was at the mercy of the computer elite who could implement his data logger and provide the necessary computer resources to analyze his data. The process was expensive, both in time and in money. 

The most recent extension of instrument automation has come with the availability of practical laboratory robotics systems. These systems can be as easy to implement as the personal computer data system and extend automation beyond control, data collection and... 

At Sirius, a dedicated instmment (Profiler LDA) has been developed for the rapid measurement of log D by liquid-liquid partition chromatography. In this instrument the column is coated with a layer of octanol, and the retention times are therefore tmly related to octanol/water partitioning. Although the method used was first described 25 years ago [29], it has been difficult to apply in an automated system because of the tendency of octanol to be flushed from the column by the eluent, thus requiring frequent renewals of the octanol coating. In our method, the octanol coating is kept in place by reversing the direction of the eluent after each... 

Hollow-cathode lamps are currently available for over sixty elements. Several multi-element lamps have been constructed and are useful for routine determinations, but they have proved to be of doubtful performance up to now. More successful with regard to multi-element analysis have been computer controlled automated systems, which enable a programme of sequential measurements to be made with instrumental parameters being adjusted to the optimum for each element to be measured. 

Most manufacturers of dissolution testing devices offer semi-automated systems that can perform sampling, filtration, and UV reading or data collection. These systems automate only a single test at a time. Fully automated systems typically automate entire processes including media preparation, media dispensing, tablet or capsule drop, sample removal, filtration, sample collection or analysis (via direct connection to spectrophotometers or HPLCs), and wash cycles. A fully automated system allows automatic performance of a series of tests to fully utilize unused night and weekend instrument availability. 

References Guidelines for Safe and Reliable Instrumented Protective Systems, American Institute of Chemical Engineers, New York, 2007 ISA TR84.00.04, Guidelines for the Implementation of ANSI/ISA 84.00.01-2004 (IEC 61511), Instrumentation, Systems, and Automation Society, N.C., 2005 ANSI/ISA 84.00.01-2004, Functional Safety Safety Instrumented Systems for the Process Industry Sector, Instrumentation, Systems, and Automation Society, N.C., 2004 IEC 61511, Functional Safety Safety Instrumented Systems for the Process Industry Sector, International Electrotechnical Commission, Geneva, Switzerland, 2003. 

The determination of the orthophosphate was carried out by using the automated systems described by the Technicon Instruments Corporation. The manifolds used are shown in Fig. 12.3. The procedures referred to below as methods I and II are Technicon industrial methods Nos. 94-70W and 155-71W, respectively. Method I includes ascorbic acid alone for the reduction of the molybdophosphoric acid whereas in method II the mixed reagents ascorbic acid, sulphuric acid, ammonium molybdate and antimony potassium tartrate are used. Method I is intended for use for high levels of phosphorus (up to lOpg ml4) and method II for low levels (less than 0.5pg ml4). The wetting agent (Levor IV) used in order to obtain a smooth bubble pattern, is present in the ascorbic acid reagent line for method I whereas it is added externally Fig. 12.3) in the water line (0.5pg ml4 of Levor) in method II. 

Other automated systems may be purchased for a specific purpose and are called dedicated instruments, e.g. glucose analyser. Others have fairly restricted applications, an example being the reaction rate analysers which are specifically designed for the kinetic measurements of enzyme activity. Some of the more recently developed instruments employ individual pre-prepared disposable test packs or strip devices which contain all the reagents for each particular assay in a dry form. 

The core components of a CE instrument are a power supply, a detector, and devices that allow for temperature control of the capillary and sample compartment. A wide variety of commercial CE instruments are available, from simple modular systems to fully integrated automated systems under computer control. 

When peak-width at the basehne is used, the overall shape of the peak is insignificant and the simple measurement of time characterizes the analytical signals. Originally, two FIA approaches were introduced— the American AMFIA System which attempted to provide an automated system using HPLC instrumentation, and a manual unit which was developed by Ruzicka and Hansen [40]. A novel development of FIA has recently been... 

The majority of commercial developments which relate to the automation of GC and HPLC pay little attention to sample preparation. There are few examples where pretreatment is not required. A fully automated system was developed by Stockwell and Sawyer [23] for the determination of the ethanol content of tinctures and essences to estimate the tax payable on them. An instrument was designed and patented which coupled the sample pre-treatment modules, based on conventional AutoAnalyzer modules, to a GC incorporating data-processing facihties. A unique sample-injection interface is used to transfer samples from the manifold onto the GC column. The pretreated samples are directed to the interface vessel hy a simple hi directional valve. An ahquot (of the order of 1 ml) can then he injected on to the GC column through the capillary tube using a time-over pressure system. 

The automation of the HPGPC/Viscometer system is achieved by interfacing the differential refractometer (DRI) and viscosity detector to a microcomputer for data acquisition. The raw data subsequently, are transferred to a minicomputer (DEC PDP-ll/HiI) for storage and data analysis. Details of the instrument automation are given elsewhere.(6)... 

There is a wide variety of instrumentation ranging from simple manually operated devices to completely automated systems. Briefly, the polymer-containing solution and solvent alone are introduced into the system and pumped through separate columns at a specific rate. The differences in refractive index between the solvent itself and polymer solution are determined using a differential refractometer. This allows calculation of the amount of polymer present as the solution passes out of the column. 

Written procedures and practices must be in place within the laboratory to verify the accuracy of manually entered and electronically transferred data collected on automated systems. The primary documentation for data entry requirements is an audit trail. Laboratories must ensure that an audit trail exists and is maintained. This audit trail must indicate date and time stamps for each record transmitted and the source instrument for each entry. 

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