Automatic sampling

Sample reduction in successive stages—primaiy to secondaiy, secondary to tertiary etc.—can be fulfilled using automatic sampling equipment while observing design principles of statistical sampling. Alternatively, sample quantity reduction may be carried out in a lab-oratoiy. 

NC samples were irradiated for 3 min and TNT and HMX for 1 min at a 14 MeV neutron flux of approx 108n/cmasec, Simultaneous counting was performed by means of a matched dual 7.6x7.6cm flat Nal crystal detector assembly in conjunction with a Kaman Nuclear programmed timer system for automatic sample transfer, A one-min count time was usually sufficient to exceed 10 counts. The signal from each de-... 

Tbday all automatic sample applicators blanket the plate with nitrogen firstly this has the effect that the applied starting zones dry quickly and secondly serves to prevent oxidation of the applied substances. 

The products resulting from the reaction were injected vrith an automatic sampling valve into a GIRA GC 181 gas phase chromatograph and analyzed with a flame ionization detector. The separation was carried out in a capillary column DB5 (J and W Scientific). 

Table 5.5 shows the main characteristics of UV spectrophotometry as applied to polymer/additive analysis. Growing interest in automatic sample processing looks upon spectrophotometry as a convenient detection technique due to the relatively low cost of the equipment and easy and cheap maintenance. The main advantage of UV/VIS spectroscopy is its extreme sensitivity, which permits typical absorption detection limits in solution of 10-5 M (conventional transmission) to 10 7 M (photoacoustic). The use of low concentrations of substrates gives relatively ideal solutions [20]. As UV/VIS spectra of analytes in solution show little fine structure, the technique is of relatively low diagnostic value on the other hand, it is one of the most widely used for quantitative analysis. Absorption of UV/VIS light is quantitatively highly accurate. The simple linear relationship between... 

Discontinuous analysis must in the first place and at a recorded moment provide for automatic sampling directly from the process product or stream in the second place, and by direct connection, the analytical measurement must be carried out in a fully automatic manner. 

The outline of the construction of a typical plasma emission spectrometer is to be seen in Figure 8.10. The example shown has an inductively coupled plasma, excitation source, but the outline would be similar were a dc source to be fitted. Different combinations of prisms and diffraction gratings may be used in the dispersion of the emitted radiation, and in the presentation of the analytical signal. Instruments are computerized in operation and make use of automatic sample handling. Sophisticated data handling packages are employed routinely to deal with interferences, and to provide for clarity in data output. 

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. 

American Petroleum Institute (API), Manual of Petroleum Measurement Standards. Chapter 8.2. Automatic Sampling of Petroleum and Petroleum Products. First Edition, API Washington, D.C., 1987. 

The instrumentation for sensors based on absorption measurements can be designed on the traditional spectrophotometers by using a flowthrough cell for automatic sampling with the sensors mounted inside the flow-through cell shown in Fig. 20a.3. For remote optical sensing using optical fibers, the chromophores can be immobilized in reflective... 

The Gilson Aspec automatic sample preparation system is a fully automated system for solid-phase extraction on disposable columns and online HPLC analysis. The Aspec system offers total automation and total control of the entire sample preparation process including clean-up and concentration. In addition, Aspec can automatically inject prepared samples into on-line HPLC systems. 

Aspec Automatic sample preparation system Asted automated sequence trace diazylate enricher 231/401 HPLC autosampling injector 232/401 automatic sample processor and injector ... 

LSC 2000 (concentrator) ALS 2016, 2032, (discrete automatic samplers) automatic sample heater ALS 2050 (vial sampling system)... 

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