High resolution selected reaction monitoring

A scan-by-scan calibration correction method used, for example, in high resolution selected reaction monitoring, H-SRM. 

Moritz, T. Olsen, J.E. Comparison Between High-Resolution Selected Ion Monitoring, Selected Reaction Monitoring, and Four-Sector Tandem Mass Spectrometry in Quantitative Analysis of Gib-berellins in Milligram Amounts of Plant Tissue. Anal. Chem. 1995, 67, 1711-1716. 

Highly resolved selected reaction monitoring, MS/MS target compound scan technique using enhanced mass resolution at Q1 of a triple quadrupole analyzer for increased analyte selectivity. 

To ensure that appropriate resolution and lack of interference is obtained during method development, it is highly recommended actively monitoring PLs and aware of the retention/elution times and intensity of the PLs relative to the retention/elu-tion times for the analytes of the interest. Table 2 summarizes several representative Selective Reaction Monitoring (SRM) transitions for PLs monitoring purpose during method development. 

Amelia Peterson et al, University Wisconsin, Prof Josh Coon group, published first results on the implementation of an EI/CI interface on a hybrid Orbitrap system for ultra-high resolution GC-MS using a GC-Quadrupole-Orbitrap configuration for full scan, SIM, MS/MS and SRM (selected reaction monitoring) at the ASMS conference. 

A recent development for the improved mass resolution of quadrupole analysers has been published and commercialized for a SIM technique in MS/MS named H-SRM (< 0.4 Da) or U-SRM (< 0.2 Da), selected reaction monitoring by using enhanced mass resolution. Hyperbolic quadrupole rods of a true hyperbolic pole face, high-precision four-section design with a rod length of 25 cm length... 

The catalyst exhibited high enantiomer selectivity in the reaction of the six-membered cyclic acetate roc-lab with KSAc on a 2.5 mmol scale. This led to the isolation of the thioacetate 19aa with 97% ee in 48% yield and the acetate ent-lab with >99% ee in 43% yield (entry 8). The reaction came to a practically complete halt after 51% conversion of the substrate. In order to determine the selectivity factor S, the kinetic resolution of roc-lab was repeated and the ee values of the acetate and thioacetate were monitored over the whole course of the reaction (Fig. 

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