Absolute mass spectrometry: A theoretical analytical technique for quantification

Abstract

Mass spectrometry (MS) is an analytical chemistry technique that requires calibration with standards in order to quantify an analyte in a sample. In many cases the reference standards may be difficult to obtain or unavailable. In fact, when MS is applied to study reactions that yield multiple products, their quantification requires several standards and involves time-consuming and tedious calibration procedures. In other applications like Mass Spectrometry Imaging (MSI), quantification becomes even more tedious when on-tissue standards or mimetic tissue models are required. In this work, we introduce a new measurement technique that we called the Absolute Mass Spectrometry (AbMS), which allows the absolute quantification of an analyte without the need for calibration standards. This technique is based on the “Influence Method” developed in 2015 for nuclear measurements which, when applied to MS, produces this improvement for analyte quantification. Two possible applications of this technique are presented. One is the conceptual development of a mass spectrometer with electronic ionization that does not require calibration to determine the amount of analyte. The other one describes how to apply this technique in a mass spectrometer with other ionization sources like MALDI, DESI, and SIMS, which are used in MSI. AbMS technique uses the conceptual basis of Influence Method and two consecutive measurements to estimate the amount of analyte. Specifically, AbMS can be directly employed as an absolute method for quantification in MSI. Therefore, it constitutes an attractive complement for research applications in pharmaceutical and health sciences.