Parent scan

In a screening approach, non-ionic surfactants were monitored in the form of their [M + NH4]+ ions, equally spaced with Am/z 44 and identified by FIA-MS-MS(+) in combination with APCI or ESI interface [34,35]. Ci8-SPE was performed prior to selective elution by diethyl ether [35]. Ions of the non-ionics of AE type at m/z 350-570 (Am/z 44) were identified as surfactants with the general formula Ci3H27-0(CH2CH20)mH (m = 3-7). The complexity of the mixture confirmed the results using the diagnostic parent scans m/z 89 for aliphatic non-ionic surfactants of ethoxylate type necessary [35]. 

A) Daughter scan B) Parent scan C) Neutral loss scan D) Reaction monitoring... 

ZZ ZH He 25 positive Ion ESI, precursor (parent) scan of rrVz 184, with He as collision gas at 25 V offset using a triple-stage quadrupoie... 

Although daughter scans are most commonly used in the MS-MS applications, parent scans yield the most interference-free biomarker distributions. In a parent scan mode, second-stage MS is used as a filter to allow selected ions characteristic to biomarkers to fly through while first-stage MS is scanned to record the molecular ions that produce the selected ions. Only biomarker compounds that can yield both the molecular and characteristic fragment ions are... 

Figure 5 Gas chromatography-mass spectrometry-mass spectrometric chromatograms of steranes in a mature oil. Conditions are the same as Figure 3 except the acquisition being in parent scan mode rather than a full-scan mode residence time per parent mass, 100 msec.

Johnson, J. V. Pedder, R. E. Yost, R. A. MS-MS parent scans on a quadrupole ion trap mass spectrometer by simultaneous resonant excitation of multiple ions. Int. J. Mass Spectrom. Ion Proc. 1991, 106, 197-212. 

Fixed-product ion scans (sector instruments). High-voltage scan or linked scan at constant B /E. Both techniques give a spectrum of all precursor (parent) ions that fragment to yield a preselected product (daughter) ion. 

Constant neutral loss (or fixed neutral fragment) scans. The linked scan at constant B[1 -(E/Eg)] /E gives a spectrum of all product (daughter) ions that have been formed by loss of a preselected neutral fragment from any precursor (parent) ions. 

The most common modes of operation for ms/ms systems include daughter scan, parent ion scan, neutral loss scan, and selected reaction monitoring. The mode chosen depends on the information required. Stmctural identification is generally obtained using daughter or parent ion scan. The mass analyzers commonly used in tandem systems include quadmpole, magnetic-sector, electric-sector, time-of-flight, and ion cyclotron resonance. Some instmments add a third analyzer such as the triple quadmpole ms (27). 

Fig. n Fluorescence scan of a Chelidonium extract chromatogram track with ca 5 ig chelidonin (A) before and (B) after 1 h irradiation with short-wavelength UV light two new zones are ap parent that were not previously detected [25, 26]. 

Mode Interface Spray voltage Sheath gas Auxiliary gas Capillary temperature Manifold temperature Collision gas Total scan time QIMS resolution voltage added Q3MS resolution voltage added Parent masses... 

Figure 4. Scanning electronic microscope images (x5000) of (a) parent PET film (b) PET film treated in DMF at 140°C for 13 min (c) 10.5 pHEKA containing PET film.

Tandem mass spectrometry (70eVEI) performed on 5-amino-l,3,4-thiadiazole-2-thiol 26 gave a weak abundance peak at m/z 78 Da (2%) corresponding to the [CH2S2]+ ion (Equation 1) <1999PCA5123>. The linked-scan spectra of the parent ion (M+) and the ion at mfz 106 showed that loss of HNC followed by N2 elimination accounted for the... 

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