Quantitation selected reaction monitoring

Figure 5.67 Reconstructed ion chromatograms for Idoxifene and internal standard (ds-Idoxifene using LC-ToF-MS for (a) double-blank human plasma extract, (b) extract of blank human plasma containing internal standard (IS), and (c) control-blank human plasma spiked with Idoxifene at 5 gml , the LOQ of the method. Reprinted from 7. Chromatogr., B, 757, Comparison between liquid chromatography-time-of-flight mass spectrometry and selected-reaction monitoring liquid chromatography-mass spectrometry for quantitative determination of Idoxifene in human plasma , Zhang, H. and Henion, J., 151-159, Copyright (2001), with permission from Elsevier Science.

The instrument scan mode called selected reaction monitoring (SRM) is generally used for quantitative applications. SRM is similar to selected ion monitoring (SIM) in single quadrupole MS. The difference is that a product ion from the decomposition reaction in the collision cell is measured instead of a single ion formed in the... 

The software tools accompanying the QTRAP MS/MS allow set-up of multiple selected reaction monitoring (SRM) transitions for all likely metabolites after the major product ion transitions for the dosed compound are known. Because QTRAP MS/MS can monitor up to 100 SRM transitions during a single assay, the SRM transitions required for quantitation of the dosed compound and internal standard are obtained along with the possible metabolite transitions. During sample analysis, when a possible metabolite transition exceeds a preset threshold value, the QTRAP MS/MS performs an enhanced product ion (EPI) scan. When the assay is complete, the EPI scans can be used to determine whether the hits are metabolites, and if they are metabolites, what part of the molecule has changed. Thus, one analytical run provides both quantitative and metabolite information. 

Moritz, T. Olsen, J.E. Comparison Between High-Resolution Selected Ion Monitoring, Selected Reaction Monitoring, and Four-Sector Tandem Mass Spectrometry in Quantitative Analysis of Gib-berellins in Milligram Amounts of Plant Tissue. Anal. Chem. 1995, 67, 1711-1716. 

The use of MALDI for the analysis of small molecules was recently reported. Particularly attractive is the coupling of a MALDI source with a triple quadrupole mass analyzer for quantitative analysis in the selected reaction monitoring (SRM) mode due to very high analysis speed. 

The major advantage of this instrument is that qualitative and quantitative analysis can be performed in the same LC-MS run. As an example in a data-dependent experiment, the selected reaction monitoring mode can be used as a survey scan and the enhanced product ion mode (EPI) as a dependent scan. The consequence is that for each quantified analyte a confirmatory MS/MS spectmm can be obtained. 

Perri, E., A. Raffaelli, and G. Sindona. OE067 Quantitation of oleuropein in virgin olive oil by ionspray mass spectrometry-selected reaction monitoring. J OE068 Agr Food Chem 1999 47(10) 4156-4160. 

Selected Reaction Monitoring (MS/MS) Selected reaction monitoring (SRM) is the process by which the first mass analysis selects a specific m/z (the precursor ion) to be fragmented in the collision cell and the second mass analysis selects and detects a specific product ion. Most commonly used in the quantitative analysis of well-characterized, targeted species for which optimized precursor-product pairs can be established. In SRM-based LC-MS assays no qualitative information can be obtained. However, SRM can be used to trigger product ion, neutral loss, or precursor ion scans. 

King, R. C., Gundersdorf, R., and Femandez-Metzler, C. L. (2003). Collection of selected reaction monitoring and full scan data on a time scale suitable for target compound quantitative analysis by liquid chromatography/tandem mass spectrometry. Rapid Commun. Mass Spectrom. 17 2413-2422. 

Zhang, H., and Henion, J. (2001). Comparison between liquid chromatography-time-of-flight mass spectrometry and selected reaction monitoring liquid chromatography-mass spectrometry for quantitative determination of idoxifene in human plasma. J. Chromatogr. B Biomed. Sci. Appl. 757 151-159. 

Leuthold, L. A., Grivet, C., Allen, M., Baumert, M., and Hopfgartner, G. (2004). Simultaneous selected reaction monitoring, MS /MS and MS3 quantitation for the analysis of pharmaceutical compounds in human plasma using chip-based infusion. Rapid Commun. Mass Spectrom. 18 1995-2000. 

Macek et al. [120] developed a method to quantitate omeprazole in human plasma using liquid chromatography-tandem mass spectrometry. The method is based on the protein precipitation with acetonitrile and a reversed-phase liquid chromatography performed on an octadecylsilica column (55 x 2 mm, 3 /im). The mobile phase consisted of methanol-10 mM ammonium acetate (60 40). Omeprazole and the internal standard, flunitra-zepam, elute at 0.80 0.1 min with a total rim time 1.35 min. Quantification was through positive-ion made and selected reaction monitoring mode at m/z 346.1 —> 197.9 for omeprazole and m/z 314 —> 268 for flunitrazepam, respectively. The lower limit of quantification was 1.2 ng/ml using 0.25 ml of plasma and linearity was observed from 1.2 to 1200 ng/ml. The method was applied to the analysis of samples from a pharmacokinetic study. 

Pharmacokinetics Quantitative bioanalysis Selected ion monitoring Selected reaction monitoring Automated off-line solid-phase extraction Automated on-line extraction Fouda et al., 1991 Wang-Iverson et al., 1992 Covey et al., 1986 Kaye et al., 1992 Allanson et al., 1996 Simpson et al., 1998 Needham et al., 1998... 

DE, two-dimensional gel electrophoresis WB, Western blot MS, mass spectrometry LC, liquid chromatography 2DE DICE, two-dimensional difference gel electrophoresis, SRM, selected-reaction monitoring MRM, multiple reaction monitoring AQUA, absolute protein quantitation SMIM, selected MS/MS ion monitoring. ... 

K. A. Francesconi, S. A. Pergantis, Application of selected reaction monitoring tandem mass spectrometry to the quantitative determination of an arsenic-containing nucleoside in a crude biological extract, Analyst, 129 (2004), 398-399. 

For purposes of quantitative analysis, selected ion monitoring (SIM) and selected reaction monitoring (SRM) are two commonly utilized approaches. The latter is also referred to as multiple reaction monitoring (MRM). In both modes, considerable structural information is lost nonetheless, these techniques are extremely powerful for target compound quantihcation in biological matrices, if the compound of interest is known. 

The use of selected reaction monitoring (SRM) methods for quantitative bioanalysis represents increased dimensions of mass spectrometry analysis. A SRM method that features a tandem quadrupole MS/MS instrument for the quantitative analysis of an antipsychotic agent, clozapine, in human plasma was recently described by Dear et al. l Preclinical development studies of clozapine in rats and dogs used HPLC with fluorescence detection (FLD). With this method, a better limit of quantitation (LOQ) of Ing/ml was obtained. As the compound moved into the clinical stages of development, a more sensitive method of... 

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