Multiple reaction monitoring chromatograms

FIGURE 1.9 Multiple reaction monitored ion chromatograms for desloratadine (top), 3-hydroxydesloratadine (middle), and phosphatidylcholine monoester (bottom) during post-column infusion and subsequent injection of a SPEC(R) MPl-extracted control blank plasma sample.111 (Reproduced with permission from Elsevier.)... 

FIGURE 11.6 Representative multiple reaction monitoring (MRM) chromatogram of whole blood of patient treated with sirolimus (A) m/z 931.5 — 864.6 represents transition of sirolimus at concentration of 10 pg/L eluted at 0.93 min (B) m/z 809.4 — 756.4 represents transition of internal standard ascomycin eluted at 0.89 min. (Source Wallemacq, P.E. et al., Clin Chem Lab Med. 41, 922, 2003. With permission.)... 

Fig. 3.109. Expanded chromatogram sections showing the multiple reaction monitoring detection of the isomers (a) 3-/4-SPI (b) pure 3-SPI (c) SPAA and (d) SPA. Reprinted with permission from T. Reemtsma [165].

Fig. 4.7.2 Multiple reaction monitoring (MRM) chromatogram of pooled urine spiked with C7-polyols produced by method 1 (without separation of polyol isomers). MRM transitions are given for each mass transition. IS Internal standard...

Lopshire [188] explored the exchange reaction of chlorine by oxygen with polychlorobiphenyl anions as a method of compound-selective polychloro-biphenyl congener detection in a gas chromatography-mass spectrometric system. Multiple reaction monitoring allowed separate chromatograms to be detected for each different polychlorobiphenyl composition from tetra-through nonachloro. 

Figure 5.4 Chromatograms with multiple reaction monitoring (MRM) transitions at 625/287 (A) and 639/301 (B) that show the multiple glucuronide forms of cyaniding-3-glucoside and peonidin-3-glucoside, respectively. (From Hager, 2008).

Figure 15 Electrospray positive multiple-reaction monitoring (MRM) chromatograms for seven dosed compounds plus an analytical internal standard (top chromatogram). Compounds were extracted from brain tissue (2.5 ng/mL) by 96-well semiautomated liquid-liquid extraction.

FIGURE 26.9 A multiple reaction monitoring (MRM) LC-MS chromatogram with a baseline-separation of all spirolides in a Nova Scotian strain of Alexandrium ostenfeldii (AOSH2). 

Figure 2.2 Scan types utilized in lipidomic analysis by ESl-MS/MS. An MS/MS instrument consists of an initial mass (m/z) analyzer (MSi), a collision cell, and a second mass (m/z) analyzer (MSj). The two mass (m/z) analyzers and collision cell are separated in space on a beam instrument, such as tandem quadrupoles and Q-TOFs, and in time in ion traps. Product-ion, precursor-ion, and neutral-loss scans are performed by respectively scanning MSj, MSj, or MSj and MS2 in parallel. Multiple reaction monitoring (MRM) chromatograms are recorded with MSj and MSj fixed for transitions of interest. MS or MS/MS/MS spectra are recorded when a third mass (m/z) analyzer MS3 is utilized following a second collision cell. MS and further MS" spectra are often recorded on ion-trap instruments.

Fig. 3 Reversed-phase HPLC-MS/MS chromatogram using formic acid in the mobile phase and an Atlantis dC18 column. The standard mixture of alkyl phosphonic acids with a concentration of 10 p,g/ml each was detected using multiple reaction monitoring (MRM) 1) methylphosphonic acid (MPA, miz 96.8 78.7) 2) ethyl methylphosphonic acid (EMPA, mIz 125 96.8) 3) C>-elhyl A,A-dimethylamidophosphoric add (EDMAPA, miz 154.2—>126) 4) isopropyl methylphosphonic acid (iPrMPA, nJz 139.1 %.8) 5) pinacolyl methylphosphonic acid (PinMPA, miz 181.3- 96.8) 6) diisopropyl methylphosphonic add (DiPrMPA, mk 181.3 139.1). See the text for further chromatogr hic details and the MS/MS conditions used.

Figure 11.17 (a) Chemical structures of macrolide antibiotics (note that erythromycin, ETM, was analyzed as its anhydro form shown, (ETM-H2O)), but tylosin (TLS) was analyzed as the intact protonated molecule. Spiromycin (SPM) was used as the internal standard, (b) Multiple reaction monitoring (MRM) chromatograms of macrolides, each spiked at a concentration of 300ng.L before extraction from 100 mL of influent wastewater from a water reclamation plant. The MRM transitions used for quantitation are shown in each case (the precursor ion for Spiromycin I was the (M+2H) + ion, the others were (M+H)+ ions), and the total ion current (TIC) chromatogram is simply the sum of the three MRM traces. Reproduced from Yang, Anal. Bioanal Chem. 385, 623 (2006), with permission from Springer Science and Business Media. 

Fig. 2. Total Ion chromatogram of Cal 4. The retention times demonstrate co-elution of some compounds. Deuterated internal standards elute at the same time as the non-deuterated analog. All compounds are detected based on multiple reaction monitoring (see Table 2).

SIM (selected ion monitoring)/MID (multiple ion detection) or SRM (selected reaction monitoring)/MRM (multiple reaction monitoring) analyses give a chromatogram in the same way but no mass spectrum is retrievable. The TIC in this case is composed of the intensities of the selected ions. Analyses, where switching from individual masses to fixed retention times is planned, often show clear jumps in the base line (see Figure 2.162). 

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