Combined instruments

Pressure recording controller (differential), pneumatic transmission with pressure recorder, combined instrument board mounted... 

Fig. 6. A typical correlation function obtained for IFABP in 20 mM phosphate buffer at pH 7.3 at room temperature. The experiment was performed using a ConfoCor 2 LSM combination instrument (Carl Zeiss-Evotec, Jena, Germany) and the correlation function data (G(t)) were fitted to the form G(r) = G(0)/(1 + x/rD), where Td is the characteristic diffusion time. An additional exponential component improves the fit. 

Once into the 21st century, hyphenated instrumentation (i.e., those that couple two instruments together) became prevalent in laboratories. This is the combination of two or more, often different, instruments. In simple terms, the purpose is to first separate the analyte of interest and then to identify it. This takes place using a sample injected into the combined instruments. The most common of the hyphenated instruments is the gas chromatograph, the output of which is fed into a mass spectrometer to produce a gas chromatography-mass spectrometry (GC-MS) [35],... 

The importance of these surface-analysis techniques has resulted in the development of a range of highly automated instruments. In the effort to obtain multiple analytical data, a trend has occurred during the last ten years to build combined instruments, that is apparatus which will permit measurements by several techniques, in a single vacuum system. In this way, greater utilization of the complex instrumentation involved and a more economic use of the functional parameters of the instruments are ensured. 

Other areas of geologic research that can be explored using a combined instrumentation approach are many. Surface reactions of solids that have been suspended in aqueous solutions can be studied this type of work has important applications in mineral processing research. The analysis of precious and strategic metal ores can be studied in order to monitor their inherent material and chemical properties and their surface characteristics before and after reaction. 

S. Scharbert, N. Holzmann and T. Hofmann, Identification of the astringent taste compounds in black tea infusions by combining instrumental analysis and human bioresponse, J. Agric. Food Chem., 52 (2004) 3498-3508. 

Combined gas chromatography-mass spectrometry (GC-MS) takes advantage of the separating power of the gas chromatograph and the identification power of mass spectrometry. The gas chromatograph separates the components and provides retention time data and the mass spectrometer identifies the components. The combined instrumentation has the potential to provide very useful information in FDR casework. Figure 16.5 illustrates a quadrupole mass spectrometer. 

Organic FDR detection is a useful additional technique, despite the fact that single-based propellant constituents cannot be reliably detected. The current system uses GC/TEA as a rapid screening technique for NG and 2,4-DNT, and only positive samples need to be subjected to the SPE cleanup/ concentration procedure. The method is flexible in that the extract can be analyzed by a range of analytical instrumentation. There does not appear to be good correlation between the detection of organic and inorganic FDR which emphasizes the need for combined instrumentation, that is, GC/TEA, GC/MS, and SEM/EDX. Details of the method devised are as follows. 

For ICP-AES both sequential and simultaneous as well as combined instruments are used. In sequential spectrometers special attention is given to the speed of the wavelength access and in simultaneous spectrometers to the provision of background correction facilities. In combined instruments a number of frequently used channels are fixed and with a moving detector or an integrated monochromator... 

Analyte identification based only on the retention time of a component is suspect even for simple mixtures. Selective detectors reduce the uncertainty to some extent by detecting only the components sharing a certain characteristic, but these do not eliminate the chance of false identification. On the other hand, spectroscopic techniques provide qualitative information about the analyte which is often specific enough to make the identification of a component certain. It is therefore not surprising that attempts to couple GC with various spectroscopic techniques were undertaken from the early days of GC. Today, combined instruments, often referred to as hyphenated systems, are used routinely, and gradually replace conventional gas chromatographs in many areas. 

Numerous additional advances in GC/MS occurred throughout the last decade. Mass spectrometers have now become almost routine, reliable instruments. Improvements in design of both sector and quadrupole instruments is today reflected in greater spectral resolution and sensitivity parameters. Versatility of the GC/MS combined instruments has been dramatically improved by better interfacing techniques and an increased use of capillary columns. The chemical ionization methods have become important for work with relatively unstable molecules there is a significant rationale for their increasing use in biochemical research. 

Electrically active regions of nanocrystalline silicon (nc-Si) films have been investigated by using a SEM/STM combined instrument. STM constant current images reveal a cell structure in the nc-Si which is also observed in the remote electron beam induced mode of the STM. The STM-REBIC contrast indicates the existence of space charge regions at the cell boundaries. 

Basic symbols for combination instrument Of device with two services orfunctions... 

Temperoture recording controller ond temperoture recorder, combined instrument boord mounted... 

M+NH4] ", with a S/N of approximately 5. The scan range was from m/z 500 to 1000 with a scan cycle time of 1.1 s. The tristearin result is a "worst case" result. Logistical difficulties of combining instruments from two distant sites over a short period of time precluded optimization of S/N. 

To determine several gases simultaneously, the major suppliers offer combination instruments having more than one electrochemical sensor. Devices with up to 5 sensors are available at the present time. 

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