Positive ion FAB mass spectrum

FIGURE 10. Positive Ion FAB Mass Spectrum of Racemic Sotalol. Instrument AEI, MS9. Medium glycerol... 

The positive ion FAB mass spectrum of polyether II (Figure 7.3b, Scheme 7.1) reveals, in addition to the above features, that many peaks correspond to unexpected oligomers having one (peaks at m/z 762 and 1550 863 and 1551 881 and 1669) or two butyl end-groups (peaks at m/z 819 and 1607). These products were formed by reaction between the butyl group of the... 

Positive ions FAB mass spectrum of macrocycUc Schiff bases formed in the condensation of isophthaldehyde with ethylenediamine. 

Positive ions FAB mass spectrum of poly(resordnol phathalate) (polyester II). (Reprinted with permission from Ref. 55, Copyright 1994, American Chemical Society.)... 

The positive ion FAB mass spectrum of the crude mixture obtained by ammonolysis shows protonated molecular ions (MH ) that can be unequivocally assigned to sequences with an alternating structure. However, several peaks present in the FAB spectrum do correspond to sequences containing blocks of two, three, or four consecutive units of BPA. Tliis indicates that a... 

Figure 7.16 reports the positive ion FAB mass spectrum of the one HPLC fraction of the methanolysis products of the P(HB-co-HV) copolymer... 

Positive ions FAB mass spectrum of a HPLC fraction collected from methanolysis products of the copolyester (PHB-co-15%HV). 3-Nitrobenzyl alcohol doped with NaCl is used as a matrix. 

Figure 2.7. Positive-ion FAB mass spectrum of Tyr-Gly-Gly-Phe-Met-Arg-Gly-Leu acquired using glycerol as the matrix.

Figure 12.2 Positive-ion FAB mass spectrum of a branched-chain sodium alkylbenzene sulphonate in a glycerol matrix. 

Fig. 2. The positive ion FAB mass spectrum of the octapeptide 6. The peaks marked G represent protonated polymers of glycerol.

The partial positive ion FAB mass spectrum (obtained by Xe bombardment) is shown in Fig. 2 and incorporates an abundant protonated molecular ion at m/z 1040. Three clearly defined series of diagnostic fragment ions, corresponding to the general structures (1) (N-terminal), (2) (N-terminal) and (3) (C-terminal) identify the sequence as PhCO-Ala-Phe-Val-Ile-Asp-Asp-Glu-Gln (or /.yo-Gln). The negative ion FAB spectrum showed an abundant [M —H] ion at m/z 1038 and the series of ions corresponding to structure (4) was able to confirm the sequence of the six C-terminal amino acids. 

Figure 7.1.5 Positive-ion FAB mass spectrum of semipermanent hair dye containing polyethoxylated (n=3-14) oleyl (A)/linoleyl (B)/ricinoleyl (C)methylammonium chloride. Adapted from Maffei Facino et al (1997) with permission.

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