Fragment selection

To understand the circumstances in which particular features of mass spectrometry, such as high-resolution measurements, MS-MS and cone-voltage fragmentation, selected-ion monitoring and selected-decomposition monitoring, may be nsed to address particular analytical problems. 

Biographical Note, by A.E. Waite.—The Stone of the Philosophers.-Certain Fragments Selected From the Letters of Edward Kelly.-The Humid Way, or, A Discourse Upon the Vegetable Menstruum of Saturn.—The Theatre of Terrestial Astronomy... 

Biographical note, by A.E. Waite.—The stone of the philosophers.—Certain fragments selected from the letters of Edward Kelly.-The humid way, or, A discourse upon the vegetable menstruum of Saturn.—The theatre of terrestial astronomy... 

Laden JC, Philibert P, Torreilles F, Pugniere M, Martineau P (2002) Expression and folding of an antibody fragment selected in vivo for high expression levels in Escherichia coli cytoplasm. Res Microbiol 153 469-474... 

I. New Procedures for Reduction of Nitroso Acetals Containing the N- OSiMejRu1 Fragment Selective reduction of cyclic nitroso acetals was briefly considered in Section 3.4.3.4.3. The latest data on catalytic hydrogenation of cyclic and NOSiN Bu -containing acyclic nitroso acetals (including... 

Willems, P.M., Hoet, R.M., Huys, E.L., Raats, J.M., Mensink, E.J., Raymakers, R.A. (1998). Specific detection of myeloma plasma cells using anti-idiotypic single chain antibody fragments selected from a phage display library. Leukemia, 12, 1295-1302. 

A 570 bp DNA fragment selected from F. culmorum DNA was amplified by means of specific primers [1]. 

Fragments selected for optimal diversity using UNITY fingerprints... 

Quantification of known analytes in PK and distribution studies makes different demands on the analytical procedure than detection of unknown compounds in biotransformation experiments or identification of unknown and postulated molecules in toxicological screening. For example, requirements for quantitative analysis of fixed analytes with optimum sensitivity and selectivity differ from those for qualitative detection of intact molecular weight or diagnostic MS/MS fragments. Selectivity of sample preparation and applicability of diverse scan modes represent relevant critical issues. The following sections address this context. 

This result indicates that radical anion (133) fragments selectively at the C—Cl bond at position 4 and that the intermolecular ET of the radical anion (134) is faster than the fragmentation of the C—Cl bond of position 7. 

Two techniques that have become preffered for ionisation of proteins/peptides is electrospray ionisation (ESI) and matrix-assisted laser desorption/ionisation (MALDI). Although different combinations of ionisation techniques and mass analyser exist, MALDI usually is coupled with a time-of-flight (TOF) (Figure 7) tube as a mass analyser while ESI is tradionally combined with quadrupole mass analysers. Instruments capable of MS/MS have the ability to select ions of particular m/z ratio from a mixture, to fragment selected ions and to record the precise masses of the resulting fragment ions. If this process is applied to the analysis of peptide ions, in principle the amino acid sequence of the peptide can be deduced. 

MEDLA Fragment Selection Based on Density Domains... 

Domain II from protein G from Streptococcus strain G148 was expressed and purified as described previously (11,22). To prepare the [ C, N]-labelled domain, the cells were grown on a defined medium containing 3g/l of a mixture of [99% 3c].giucose and [99% N]-amino-acids (EMBL, Heidelberg), supplemented with lg/1 15NH4CI (22). IgG and its Fc fragments selectively labeled with at the carbonyl carbon of particular amino-acids were prepared as described previously (21,23,24). 

Isomerization and fragmentation selectivities over the other acidic Pt-zeolite catalysts (Pt-HY and Pt-NaHY [13] as well as on a mixtiu e of HY and Pt/SiOo [15]) have been found to be roughly equal. The highest abimdance of 2,3DMB among the Cg products over Pt-HZSM (Table 1) indicated that the importance of acid catalyzed isomerization route was most important over this catalyst. 

One of the early methods for mass spectrometric analysis of microdialysis samples utilized gas chromatography with mass spectrometric detection (GC/MS). Electron ionization is one type of ionization used for GC/MS. It is a hard ionization technique, resulting in a high degree of analyte fragmentation. A softer form of ionization, chemical ionization, is also available and often results in less analyte fragmentation. Selected-ion monitoring (SIM) is used frequently with... 

---