Single Quadrupole Multiple Reaction Monitoring Q-MRM enables Quantitative Mass Spectrometry
Authors: Xue Jingchuan , Derks Rico J.E. , Wwebb William , Aisporna Aries , Giera Martin , Siuzdak Gary 
Published: May 2021

A single quadrupole combined with enhanced in-source fragmentation/annotation (EISA) was used to perform multiple reaction monitoring (Q-MRM) for quantitative mass spectrometry analysis. EISA amplifies fragmentation of traditional soft electrospray ionization to produce fragment ions that have been found to be identical to those generated in tandem mass spectrometry. We have combined EISA fragmentation data with criteria established by the European Union Commission Directive 2002/657/EC for electron ionization single quadrupole quantitative analysis to perform quantitative Q-MRM experiments. These experiments were performed on multiple types of complex samples that included a mixture of 50 standards, as well as cell and plasma extracts. The dynamic range for Q-MRM quantitative analysis was comparable to triple quadrupole multiple reaction monitoring (QqQ-MRM) analyses at up to 5 orders of magnitude with the cell and plasma extracts showing similar matrix effects across both platforms. Amino acid and fatty acid measurements performed from certified NIST 1950 plasma with isotopically labelled standards demonstrated Q-MRM accuracy in the range of 91-110% for the amino acids, 76-129% for the fatty acids, and good precision (coefficient of variation < 10%). In order to enhance specificity, a newly developed Correlated Ion Monitoring (CIM) algorithm was designed to facilitate these analyses. CIM autonomously processes, aligns, filters, and compiles multiple ions within one chromatogram enabling both precursor and in-source fragment ions to be correlated within a single chromatogram, also enabling the detection of co-eluting species based on precursor and fragment ion ratios. Q-MRM and CIM with single quadrupole instrumentation has been designed as an alternative to QqQ-MRM technology by correlating precursor and fragment ions to facilitate high sensitivity Q-MRM quantitative analysis on existing instrumentation that are generally inexpensive, easy to operate, and technically less complex. @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:3 0 0 0 1 0;}p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin:0in; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman",serif; mso-fareast-font-family:"Times New Roman";}.MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; font-size:11.0pt; mso-ansi-font-size:11.0pt; mso-bidi-font-size:11.0pt; font-family:"Calibri",sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:DengXian; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-fareast-language:ZH-CN;}.MsoPapDefault {mso-style-type:export-only; margin-bottom:8.0pt; line-height:107%;}div.WordSection1 {page:WordSection1;}