Palmitic acid mass spectrum

Palmitic acid, structure of, 1062 Palmitoleic acid, structure of, 1062 PAM resin, solid-phase peptide synthesis and, 1037 Para (m), 519 Paraffin, 91 Parallel synthesis, 586 Parent peak (mass spectrum), 410 Partial charge, 36 Pasteur, Louis, 297, 307... 

The mass spectrum of palmitic acid obtained by DE-MS with a Polaris Q ion trap external ionisation mass spectrometer is presented in Figure 4.2 (Ribechini et al., 2008a). Dominated by a base peak at mJz 87, it presents a visible molecular peak at mJz 256, accompanied by a fragment at m/z 257, possibly formed by rearrangement in the ion trap. The loss of the... 

Figure 1. Negative ion mass spectrum of the FAB desorbed palmitic acid. Ion m/z 148 is from the triethanolamine matrix.

For example, the LIFDI mass spectrum of biodiesel from oilseed rape revealed methyl esters of long-chain fatty acids as typical plant lipid constituents (Figure 14.3). The most prominent signal originated from the methyl ester of oleic acid (Ci i, m/z 296.4), accounting to 42.6% of the TII, followed by the methyl esters of linoleic acid (Ciga,m/z 294.4,23.8%), linolenic acid (Cm-,m/z 292.4,4.4%), stearic acid (Ci8 o, m/z 298.5, 2.8%), palmitic acid (Ci6 0, m/z 270.4, 1.4%), and gondoic acid (C2o i,... 

Table 8.10 Masses observed in the various fragment spectra of the three deprotonated molecular ions present in the DCI spectrum of natural cocoa butter (P = palmitic acid,...

Fig. 9.1.6. El mass spectrum of palmitic acid ethyl ester (12) (TIC retention time 18.94 min, Scan No. 1145) from GC-MS analysis...

Figure 9.1.6 shows the mass spectrum of palmitic acid ethyl ester (12) (TIC retention time 18.94min, Scan No. 1145). The major MS fragmentation patterns of the compound are similar to those of palmitic acid, except that all of the important ion species in the spectrum have mass numbers 28 units higher than the corresponding ion species in the spectrum of palmitic acid (11) for example, ion species m/z 88, 101, 157, and 284 compared to ion species m/z 60, 73, 129, and 256 (Odham and Stenhagen 1972). 

FIGURE 21.2 Ion trap mass spectrum of ESI-MS of [OPO + Li]+ ion atm/z 865.5. Both O and OCOOH are oleic acid. Both P and PCOOH are palmitic acid. OPO is l,3-dioleoy-2-palmitoyl-5n-glycerol. OCOOLi is the lithium salt of oleic acid. 

FIGURE 21.3 Ion trap mass spectrum of ESI-MS of [OPO + Li - OCOOH]+ at m/z 583.5. For abbreviations, see Figure 21.2. P CH=CHCOOH is the oc,p-unsaturated palmitic acid from the sn-2 position 0 CH=CHCOOH is a,p-unsaturated oleic acid from the. n-1,3 position (not detected) C3H4O is the loss of glycerol backbone to form acid anhydride of two fatty acids (6) P"CH=C=0 is palmitoyl ketene from the sn-2 position and 0"CH=C=0 is oleoyl ketene from the. n-1,3 position. 

Figure 8 Positive ion matrix-assisted laser desorption (MALDI) time-of-flight mass spectrum of P-cryptoxanthin paknitate isolated from tangerine juice. Post source decay was used to enhance detection of structurally significant fragment ions such as loss of toluene (m/z 698), loss of palmitic acid (m/z 534), and loss of both toluene and palmitic acid (m/z 442). (From Ref. 320.)... 

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