Mass ultra-high

The results obtained by Brewis et al. demonstrate an important feature of TOF-SIMS and that is the ultra-high mass resolution of the teehnique. Without sueh high speetral resolution, it would be impossible to resolve peaks sueh as those shown in Fig. 50 into eomponents and a great deal of information about the oxidation proeess would be unavailable. 

Mudawar I, Bowers MB (1999) Ultra-high critical heat flux (CHF) for subcooled water flow boiling. I CHF data and parametric effects for small diameter tubes. Int J Heat Mass Transfer 42 1405-1428... 

In a typical hip replacement operation, the top of the thigh bone is removed and a cavity is drilled along the direction of the long axis of the remaining bone. A metal prosthesis is placed in this cavity and secured in place with PMMA cement. In the pelvic girdle a plastic cup is fitted to act as the seat of the new, smaller hip joint. This cup is made of ultra-high molar mass poly (ethylene) and is also secured in place with PMMA cement. The components of an artificial hip joint are shown in Figure 10.1. 

Another widely used surgical procedure is knee replacement. In this operation the natural components of the knee joint are replaced with an artificial femoral component made of metal that interfaces with a tibial plateau made of ultra-high molar mass poly(ethylene). Implantation of these joints is becoming more widespread, though the demand for them is not as great as for hip replacement. 

Bijlsma L, Sancho JV, Pitarch E, Ibanez M, Hernandez F (2009) Simultaneous ultra-high-pressure liquid chromatography-tandem mass spectrometry determination of amphetamine and amphetamine-like stimulants, cocaine and its metabolites, and a cannabis metabolite in surface water and urban wastewater. J Chromatogr A 1216(15) 3078-3089... 

The ultra-high mass resolution capabilities of FTMS are illustrated in Figure 7b. This spectrum was obtained by leaking a mixture of CO,, and C H., into the chamber to a pressure of... 

Fourier transform mass spectrometry is made possible by the measurement of an AC current produced from the movement of ions within a magnetic field under ultra-high vacuum, commonly referred to as ion cyclotron motion.21 Ion motion, or the frequency of each ion, is recorded to the precision of one thousandth of a Hertz and may last for several seconds, depending on the vacuum conditions. Waveform motion recorded by the mass analyzer is subjected to a Fourier transform to extract ion frequencies that yield the corresponding mass to charge ratios. To a first approximation, motion of a single ion in a magnetic field can be defined by the equation... 

Pedrouzo M, Borrull F, Marce RM, Pocurull E (2009) Ultra-high-performance liquid chromatography-tandem mass spectrometry for determining the presence of eleven personal care products in surface and wastewaters. J Chromatogr A 1216(42) 6994-7000... 

Ayrton J. et al., 1998. Optimisation and routine use of generic ultra-high flow-rate liquid chromatography with mass spectrometric detection for the direct online analysis of pharmaceuticals in plasma. J Chromatogr A 8282 199. 

In order to obtain better and faster separation, instruments using higher pressures than common HPLC have been developed. These are often referred to as ultra-high-pressure liquid chromatographs (UPHPLC), or some similar abbreviation. They are used in a manner similar to HPLC and can be connected to mass spectrometers. 

Bayliss and co-workers [10] combined ultra-high flow rates, parallel LC columns, a multiplex electrospray source, and mass spectrometric detection for the rapid determination of pharmaceuticals in plasma using four narrow bore (50 mm x 1 mm, 30 pm Oasis HLB) or capillary (50 mm x 0.18 mm, 25 pm Oasis HLB) HPLC columns with large particle sizes (to avoid high system back-pressure) in parallel with a multiple probe injector and a MUX MS interface. Small sample aliquots were injected directly into the system without sample pre-treatment procedure, obtaining very low limits of quantification (from 1 to 5 ng/mL). 

Henchiz Y. Guillarme D. Martel S. Rudaz S. Veuthey J-L. Carrupt P-A. Fast log P determination by ultra-high-pressure liquid chromatography coupled with UV and mass spectrometry detections. Analytical andBioanalytical Chemistry, 2009, 394, 1919-1630. 

However, mass spectrometry itself offers two additional degrees of freedom . One can either resolve the complexity of a sample by going to high or even ultra-high mass resolution or one can employ tandem MS techniques to separate the fragmentation pattern of a single component from that of others in a mixture. [2,3] In practice, the coupling of separation techniques to mass spectrometry is often combined with advanced MS techniques to achieve the desired level of accuracy and reliability of analytical information. [1,7,24-27]... 

W. Gigante, J. Cheetham Ultra-high throughput affinity mass spectrometry for screening protein receptors, in Proceedings of the 51st ASMS Conference on Mass Spectrometry and Allied Topics, Montreal, 2003, WPG 049. 

The majority of H/D studies that have been reported employ quadrupole ion trap (QIT) instruments due to their ease of use, excellent sensitivity, ability to perform MS/MS experiments, compact size, and low cost. Other reports discuss the use of instruments with higher mass-resolving power such as the hybrid QqTOF instruments [47]. A few groups have utilized FT-ICR mass spectrometry, which offers ultra-high mass-resolving power and improved mass accuracy [48, 49]. 

Marin JM, Gracia-Lor E, Sancho JV et al (2009) Application of ultra-high-pressure liquid chromatography-tandem mass spectrometry to the determination of multi-class pesticides in environmental and wastewater samples Study of matrix effects. J Chromatogr A 1216 1410-1420... 

The applicability of LC LC to the (ultra) high-molar-mass polymers. Contrary to liquid chromatography under critical conditions, LC LC likely exhibits no upper limit of the sample molar mass [234]. On the other hand, if the difference in elution rates of the barrier forming small molecules and the oligomeric species is too small, the LC LC separation becomes insufficient. As a result, LC CC and LC LC may be considered mutually complementary from the point of view of their applicability in the... 

We begin with the most routine characterization methods—electrochemical methods. We then discuss various instrumental methods of analysis. Such instrumental methods can be divided into two groups ex situ methods and in situ methods. In situ means that the film on the electrode surface can be analyzed while the film is emersed in an electrolyte solution and while electrochemical reactions are occurring on/in the film. Ex situ means that the film-coated electrode must be removed from the electrolyte solution before the analysis. This is because most ex situ methods are ultra-high-vacuum techniques. Examples include x-ray photoelectron spectroscopy [37], secondary-ion mass spectrometry [38,39], and scanning or transmission electron microscopies [40]. Because ex situ methods are now part of the classical electrochemical literature, we review only in situ methods here. 

Dynamic headspace GC utilizes a constant purge of the sample with an ultra-high purity gas (i.e., helium). The purged volatiles are then adsorbed onto a trap, followed by heat desorption onto the GC for analysis. Either a flame ionization detector or mass selective detector can be used. The protocol presented here is designed to analyze a meat sample. 

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