The secondary electrospray ionization mass spectrometry (SESI-MS) technique is a highly sensitive promising technique for the analyses of complex mixtures of trace gaseous analytes in air and breath, achieving limits of detection in the pmol/mol range. However, a major weakness of the SESI-MS method is a lack of accurate quantification of gaseous analytes, which hinders its application in the biological, environmental and medical areas where the approach to relative quantification using standard is difficult for gaseous matrices. It is proposed here to develop robust absolute quantification from the ratios of SESI-MS ion signals based on kinetics of sequences of ion molecule reactions and mathematic description of ion transport processes. Thus a new ion source will be constructed, ion chemistry experiments will be carried out and a numeric model will be formulated that will lead into a practical method of absolute trace vzpour concentration calculations. The method will be validated in case studies in medical, environmental and food science areas.