may remove glycosylated side chains in a controlled, step-by-step manner using the power of MSn. Eventually, a core structure is exposed. A final fragmentation spectrum of the core structure yields a classic fingerprint which may then be referenced against a library MS/MS spectrum of the base component. In this way, a compound may be unequivocally classified.

Goal

This experiment demonstrates:
The utility of MSⁿ for structural determination and unambiguous classification of a suspected flavonoid compound.
The utility of MSⁿ for the unambiguous determination of product origin.

Experimental Conditions

Thermo Finnigan LCQ fitted with ESI probe
Infusion: 3 L/min using integrated syringe pump
Capillary temp: 150 C
Needle voltage: +4.2 kV
Sheath gas: 45 units
Auxiliary gas flow: 10 units

Results

Apiginin (Figure 1) (mw 270.2) is a base component of a class of flavonoids. The MS/MS spectrum of apiginin is rich in detail (Figure 2). Because the
LCQ imparts energy solely onto the precursor molecule, variations in collision energy generally have very little impact on the relative ratios of the product ions. The MS/MS spectrum of apiginin will be used as our library spectrum or fingerprint for the classification of Compound X whose full-scan mass spectrum is shown in Figure 3.


Figure 1. Structure and full-scan mass spectrum of apiginin.



Figure 2. Full-scan MS/MS (m/z 271) spectrum of apiginin.



Figure 3. Full
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Source:


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