Oxysterols charge-tagging

Table 2.3 Oxysterol Content of Rodent Brain and Human Cerebrospinal Fluid as Determined by Charge Tagging and LC-ESI-MS"... 

When analysis is performed on ion-trap instruments, this ion can be selected and subjected to further fragmentation. The resulting MS spectra are rich in structural information (Figure 2.15). The MS/MS spectra on tandem quadrupole or Q-TOF instruments are effectively a composite of MS2 and MS3 spectra recorded on an ion trap. Using our charge-tagging methodology, we have profiled the oxysterol content of adult, newborn, and... 

Figure 2.12 Charge tagging with the GP reagent to an oxysterol. Oxidation of an oxysterol with a 3p-hydroxy-5-ene function (e.g., 24S,25-epoxycholesterol, C -3p-ol-24S,25-epoxide) to the analogous sterol with a 3-oxo-4-ene function (24S,25-epoxycholest-4-en-3-one, C -24S,25-epoxy-3-one) followed by derivatization with GP reagent.

FIGURE 14.9 Charge-tagging of oxysterols with GP reagent. 

Meljon, A., Griffiths, W.X. (2010) Analysis of oxysterols in mature and developing brain, charge-tagging and LC-MS . Book of Abstracts, 31st Annual Meeting of the British Mass Spectrometry Society, Cardiff, September 5th-8th 2010. 

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