Desktop version

Home arrow Engineering

  • Increase font
  • Decrease font


<<   CONTENTS   >>

Mass Spectrometric Analysis

Fragmentation of Fusicoccin Using MS/MS

Figures 5.5 and 5.6 show the spectra obtained when the polarity of the voltage applied in the electrospray (ESI) (source coupling the LC and MS) was positive and negative, respectively.

Full scan spectra of fusicoccin in methanol ESI (+)

Figure 5.5 Full scan spectra of fusicoccin in methanol ESI (+).

Full scan spectra of fusicoccin in methanol ESI (-)

Figure 5.6 Full scan spectra of fusicoccin in methanol ESI (-).

The full scan spectra in the preferential formation of a sodium adduct of fusicoccin [fusicoccin+Na]+. Other species without such adduct were not detected. Multiple low intense peaks appeared, when infusing fusicoccin with ESI (-).

ESI (+) was chosen as the optimal conditions to monitor fusicoccin given that ESI (-) caused low intense peaks that we could not relate to fusicoccin.

The full scan spectra in F the preferential formation of a sodium adduct of fusicoccin [fusicoccin+Na]+. Other species without such adduct were not detected. The most abundant product ions are 633 and 431. Fragmentation (MS/MS) of the ion m/z 703.3 with the amplitude applied in the trap shown in Fig. 5.7.

Fragmentation (MS/MS) of the ion m/z 703.3 with the amplitude applied in the trap

Figure 5.7 Fragmentation (MS/MS) of the ion m/z 703.3 with the amplitude applied in the trap.

The optimal fragmentation amplitude (0.7 V) was chosen as the one causing the highest intensity of product ions keeping at least 5% of precursor ion (Fig. 5.8).

Fragmentation MS3 of m/z 703 [fusicoccin+Na]+ and analysis of the resultant ions by product ion scan mode shown in Fig. 5.9.

Figure 5.10 shows fragmentation MS3 of m/z 703 [fusicoccin+Na]+ (fragmentation route 2) and analysis of the resultant ions by product ion scan mode.

Fragmentation (MS/MS) of the ion m/z 703.3 with the amplitude applied in the trap

Figure 5.8 Fragmentation (MS/MS) of the ion m/z 703.3 with the amplitude applied in the trap.

Fragmentation MS of m/z 703 [fusicoccin+Na]* and analysis of the resultant ions by product ion scan mode

Figure 5.9 Fragmentation MS3 of m/z 703 [fusicoccin+Na]* and analysis of the resultant ions by product ion scan mode.

Fragmentation MS of m/z 703 [fusicoccin+Na]* (fragmentation route 2) and analysis of the resultant ions by product ion scan mode

Figure 5.10 Fragmentation MS3 of m/z 703 [fusicoccin+Na]* (fragmentation route 2) and analysis of the resultant ions by product ion scan mode.

Analysis of Samples on Chromatogram

Ethanol extracts obtained from the elution of the retained fraction of wheat samples from a carbon column. In addition, there was a solid extract that was extracted at Brighton University by mixing it with 5 ml methanol and sonication (30 min) (Fig. 5.11).

Figure 5.11 shows the full scan analysis from the solid extract sample. Two intense peaks can be detected, the first one with m/z 701 as most abundant ion (see spectra below), which also contains m/z 703 as isotopic ion, and in the second one, m/z 703 (rt 30-35 min) can also be detected (fusicoccin m/z).

 
<<   CONTENTS   >>

Related topics