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Automatic sampling methods

Chovan et al.30 described a system that integrates different components of bioanalysis including automatic in vitro incubation, automatic method development (mainly SRM transitions for LC/MS/ MS analysis), and a generic LC method for sample analysis to minimize human intervention and streamline information flow. Automaton software (Applied Biosystems) was used for automatic MS method development. Flow injection was used instead of a HPLC column to decrease run time to 0.8 min per injection. Two injections were performed. The first was performed to locate the precursor ion and optimal declustering potential (DP). The second injection was performed to locate the product ion and optimal collision energy (CE). [Pg.236]

Transposed laboratory methods - This first group is historically the most important as the first developments were carried out in that way. All colorimetric systems using automatic sampling feeding a fast reaction/detection line (for example, with a flow-injection procedure) have been developed from classical procedures, first to increase the analytical rate in laboratories before being transposed for off-line measurement. [Pg.255]

The classification of automatic continuous methods is based on the way in which carryover between samples successively introduced into the analyser is avoided. Two general groups have been described by Valcarcel and Luque de Castro [20]. These are illustrated in Table 2.4. [Pg.47]

Sample introduction can be accomplished in various ways. The simplest method is to use an injection valve. In more sophisticated LC, automatic sampling devices are incorporated where sample introduction is done with the help of auto-samplers and microprocessors. [Pg.8]

The chromatographic process begins by injecting the solute onto the top of the column. The solvent need not be the mobile phase, but frequently it is appropriately chosen to avoid detector interference, column/analyte interference, loss in efficiency, or all of these. Sample introduction can be accomplished in various ways. The simplest method is to use an injection valve. In more sophisticated LC systems, automatic sampling devices are incorporated where sample introduction is done with tire help of autosamplers and microprocessors. It is always best to remove particles from the sample by filtering, or centrifuging since continuous injections of particulate material will eventually cause blockage of injection devices or columns. [Pg.665]

American Society for Testing and Materials (ASTM) Annual Book of ASTM Standards, 05.03, Petroleum Products and Lubricants (III) (1988), 304. D4177—Standard method for automatic sampling of petroleum and petroleum products. [Pg.555]

Two questions, where to monitor or sample and how to obtain representative samples are both important. Surface water samples often are collected by automatic sampling devices controlled by a variety of sensors. The simplest method of collecting water is the grab technique, whereby a container is lowered into the water, rinsed, filled, and capped. Specialized samplers frequently are used to obtain water at greater depths. [Pg.445]

We believe that our data shows that the composite effect of the skin source, the skin preparation techniques, the modified flow-through diffusion cells, the automatic sampling and data collection and data reduction systems result in an improved and convenient method for carrying out in vitro transdermal diffusion experiments. [Pg.119]

Modern NIR equipment is generally robust and precise and can be operated easily by unskilled personnel [51]. Commercial instruments which have been used for bioprocess analyses include the Nicolet 740 Fourier transform infrared spectrometer [52, 53] and NIRSystems, Inc. Biotech System [54, 55]. Off-line bioprocess analysis most often involves manually placing the sample in a cuvette with optical pathlengths of 0.5 mm to 2.0 mm, although automatic sampling and transport to the spectrometer by means of tubing pump has been used (Yano and Harata, 1994). A number of different spectral acquisition methods have been successfully applied, including reflectance [55], absorbance [56], and diffuse transmittance [51]. [Pg.88]

In principle, most of these methods can be linked to a bioreactor on-line and ex-situ, with interfaces for automatic sampling similar to those used for on-line chromatography (for interfaces, see the chapter by Sonnleitner in this volume). An exception is the analysis of protein patterns by electrophoresis, which is difficult to perform automatically. [Pg.196]

For those who have access to the necessary equipment, neutron activation analysis is a convenient method for the determination of the average concentrations of trace elements in polymers. The fact that very little sample preparation is necessary contributes to its high reliability and reduces the risk of contamination to a minimum. Accuracies of 5% or better can be achieved when the concentrations are well above the detection limits. Analysis for about a dozen elements can be completed in less than an hour. To detect the elements with long-lived radioactive isotopes, about ten days are needed. If a number of samples are to be analysed, they can be irradiated simultaneously and counted sequentially using an automatic sample changer. [Pg.134]

Substantially less sample solution (1—100 pi) is required for each element measured by ETA. This feature may make ETA an attractive alternative to flame methods when multielement studies are planned. The automatic sample injectors and improved power supply modules available with the current generation of NFAA devices have combined to make ETA less of an art than it was previously. [Pg.131]

ASTM D 4177 (1982). Standard Method for Automatic Sampling of Petroleum and Petroleum Products. ASTM Committee on Standards, 1916 Race St., Philadelphia, PA 19103. [Pg.114]

When new analytical tools become available, more often than not considerations of responsibility to the patient, practicality, and economy will keep the clinical chemist from accepting such newly developed techniques without careful deliberation. It appears that presently atomic abso tion spectroscopy is slowly finding entrance into medical research and service laboratories, and there is reason to expect that this technique will find wider use and greater application than emission flame spectroscopy. Virtually all metals, with very few exceptions, can be determined by atomic absorption spectroscopy. It is anticipated that this technique not only will replace currently used analytical methods for metals, but will also make feasible the routine determination of elements now impractical by conventional means. Furthermore, the operational stability of available instruments and the simplicity of actual performance of measiurements make this technique well suited for automation, by addition of an automatic sample feed and automatic recording. [Pg.2]

The liquid or solid sample is placed in a vial, which is sealed with a septum and heated to a predetermined temperature for a period of time. Equilibrium between the sample and vapor phase is then established and a portion of the volatiles in the gas phase (headspace) is subsequently injected onto the column. Several different methods have been used to transfer headspace volatiles into the GC, from manual withdrawal that uses a gas syringe, to sophisticated automatic sampling that involves transfer lines, and valves that lead directly onto the column. [Pg.500]

Albumin in the urine sample forms an insoluble complex with antibodies to human albumin. PEG accelerates complex formation. The turbidity caused by the complexes is measured by a spectrophotometer at 340run and is a measure of albumin concentration. The background absorbance of the initial urine sample is subtracted automatically. This method is simple and less expensive than RIA, and rapid analysis of large numbers of samples is possible. The assays may be performed as either kinetic or equilibrium reactions. Kits are commer-cially available for use on automated analyzers (Roche Diagnostics). [Pg.888]


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