Analyzers paramagnetism

The relaxation enhancement displayed for canthaxanthin, 7 -apo-7 -(4-carboxyphenyl)-P-carotene and BI was analyzed to provide interspin distances. The dipolar interactions and the distances can be determined according to procedures described elsewhere (Budker et al. 1995, Rakowsky et al. 1995, Eaton and Eaton 2000, Rao et al. 2000) and based on simulations of the paramagnetic metal ion contribution, WAA. 

Molecular spectra can be analyzed for spectrometric or for spectroscopic purposes. The term spectrometric usually refers to compound identification (linking a signal to a known structure) and to the determination of its concentration. The term spectroscopic stands for interpretation of the spectrum in terms of structure (chemical, electronic, nuclear, etc.). In this chapter we will look as some theoretical and practical aspects of a key spectrometric application of bioEPR, namely, the determination of the concentration of paramagnets, also known as spin counting. Subsequently, we consider the generation of anisotropic powder EPR patterns in the computer simulation of spectra, a basic technique that underlies both spectrometric and spectroscopic applications of bioEPR. 

Off-gas analysis is routinely carried out either by mass spectrometry or by gas chromatography (GC), in contrast with traditional infrared and paramagnetic off-gas analyzers which are maintenance intensive and have slow response times and significant calibration drifts. 12 ... 

Characterization of the modified plastocyanins was by Inductively Coupled Plasma Emission Spectroscopy to analyze for Ru and Cu (1 1 ratio), and by HNMR spectroscopy. In the HNMR characterization the C2H resonance of His59 at 8.2 ppm is seen to be lost due to paramagnetic line broadening effect of the attached Ru(III), Fig. 13 [50]. In a further test it is known that the His59 s of both native plastocyanins react with diethyl pyrocarbonate (DEPC) to give an JV-ethoxyhistidine derivative, (12), which absorbs strongly at 238 nm (e 2750M- cm-i), Fig. 14 [133]. 

Infrared photometers Paramagnetic oxygen sensors Thermal conductivity sensors Distillation-type analyzers 1 930s and 1 940s Refining... 

NMR observes the chemistry of only the proton nucleus (though it can observe many other nuclei independently). This means that hetero and metallic chemistry cannot be observed directly. Thus, sulfur, nitrogen, oxygen, and metals cannot be directly analyzed by NMR, though secondary correlations can be obtained from the proton chemistry of the sample. In combination with electron spin resonance (ESR) analyzers that can operate in the fringe fields of the NMR magnet the presence of paramagnetic metals and free radicals can be quantified. 

Exhaust gas temperature measurements are made with a fine-wire R-type thermocouple connected to an Omega model 660 digital readout. Gas samples are extracted using a 6.4-millimeter (0.25-inch) O.D. water-cooled stainless-steel suction probe and then filtered, dried, and analyzed for CO, CO2, O2, UHC, and NOj . Instrumentation includes a Beckman model 864 NDIR CO2 analyzer, Beckman model 867 NDIR CO analyzer, Siemens OXYMAT 5E paramagnetic O2 analyzer, Siemens FIDAMAT 5E-E FID total hydrocarbon analyzer, and a Beckman model 955 Chemiluminescent NO/NOj, analyzer. Certified span gases are used for instrument calibration. PC-based data acquisition is available during experimentation. All of the emissions data reported here were obtained approximately 24 pipe diameters downstream of the fuel injector and represent average exhaust concentrations. 

In the analysis section, CH4, CO and CO2 concentrations are monitored with an online NDIR multiple analyzer (Advance Optima, Uras 14). For the analysis of O2 a continuous paramagnetic analyzer (Advance Optima, Magnos 106) is employed H2 is analyzed with a thermal conductivity detector (Advance Optima, Caldos 17). An analog-digital board (National Instruments, AT-M lO 64E) allows... 

---