Biological and medical sample

Additionally to the measurement as described above, a free selected number (mostly 3-11) of channels is measured (scanned) and the highest value in this window is taken as Neff. This evaluation procedure can be well applied to concentrations clear above the detection limit (by at least a factor of 100), otherwise the counting statistic will influence the "highest value" and also lead to a higher relative standard deviation (3-5%). On the other hand, the advantage is a relatively fast measurement and therefore a low sample consumption. Especially in case of biological and medical samples, when only small... 

This is very special equipment designed to operate at very low temperatures, e.g., from -30 °C to -86 °C, to age samples or to store valuable and perishable goods, like organs and tissues, biological and medical samples or vaccines. Vacuum panels are used mainly to increase the internal storage volume without increasing the energy consumption. 

PA and PT phenomena are widely used for numerous non-spectroscopic applications such as the determination of thermal diffusivity, non-destructive testing of materials (in particular the probing of sub-surface defects) by thermal wave imaging, time-resolved studies of de-excitation processes or on biological photoreceptors, studies of phase transitions, etc. Here, only spectroscopic applications are considered that demonstrate the main characteristics and the potential of photoacoustic spectroscopy (PAS). In the following, illustrative examples are presented for solids, liquids, gases, biological and medical samples. 

Extensive use beyond the field of chemistry, into biochemistry, biology, and medical science, including in vivo spectroscopy and imagmg of biological samples... 

Table 9.43 Determination of long-lived radionuclides in biological, environmental and medical samples and food.

Differing from a typical analytical or sensing instrument, chemical sensors are relatively small in size, mobile or portable. If possible, chemical sensor should require minimum or no additional reagents, and also minimum sample transportation or preparation. For many applications, the possibility of producing the sensors at modest cost, and making disposable sensor a reality, is extremely attractive. This is particularly true in many biological and medical sensing applications. 

In the determination of metals from biological and medical matrixes, thermal ionization mass spectrometry is seldom used. Disadvantages of thermal ionization MS are the great fluctuations in the results, caused by different instrumental requirements. Isotope fractionation resulting from vaporization of the sample and the dependence of this process on temperature are the main sources of error. However, the development of computer-controlled sample preparation and measurements have minimized these errors ... 

In a first pilot study analyzing 1 fil human blood which was applied directly to the FD emitter sodium, potassium, calcium, rubidium and cesium were found in one analytical run . Thus, it could be expected that FDMS using photographic detection should also be applicable to biological or medical samples without pretreatment. 

PIXE is the preferred method for such applications as the analysis of 15 to 20 elements in a thin sample such as air filters, or for automated analysis of large numbers of geological or archaeological samples, due to its short measurement time. The low absolute detection limit and good sensitivity for elements such as S, P, Cl, K and Ca, Fe make PIXE of great importance in biological and medical applications. 

Electrospray ion sources initiated the current revolution in biological and medical uses of MS, yet the chanistry of these sources is complex, and the number of useful ions derived from a sample can be few amid a complex mixture of interfering ions. When placed between the ESI source and the mass spectrometer, EAIMS and DMS instruments can isolate ions of importance, significantly simplifying mass spectra and improving signal-to-noise ratios in quantitative measurements." - This was initiated with EAIMS instruments and is now complimented with ultraFAlMS and DMS. A direct and near-immediate use of IMS in medical research has arisen with the development of cUnical applications of IMS, as described in Section 1.3. 

NIR spectrophotometry is a nondestructive method. This represents a considerable advantage for applications where the analyzed samples must not be altered (e.g., biological and medical applications [6], online process monitoring, etc.). 

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