Quantitative Determination of H2 in Human Blood by 22Ne-aided Gas Chromatography-Mass Spectrometry Using a Single Quadrupole Instrument

Abstract

Here, we present a quantitative method for H2 detection by gas chromatography-selected ion monitoring-mass spectrometry (GC-SIM-MS) using a single quadrupole instrument. Additionally, the developed method was applied to the detection of H2 in human blood by GC-SIM-MS analysis using the existing 22 Ne in air as an internal standard (IS). H2 was analyzed by GC-SIM-MS using a single quadrupole instrument with double TC-Molsieve 5A capillary columns for the separation of permanent gases. The detections of H2 (analyte) and 22 Ne (IS) were performed at m/z 2 and 22, respectively, by GC-SIM-MS. The analyte and IS were separated using He as the carrier gas. The ratio of the peak area of H2 to 22 Ne was employed to obtain a calibration curve for H2 determination in the gas phase. The proposed GC-SIM-MS method exhibited high sensitivity in terms of the limits of detection (LOD) (1.7 ppm) and quantitation (LOQ) (5.8 ppm) for H2 analysis. The developed quantitative assay of H2 in the headspace of blood samples achieved high repeatability with a relative standard deviation (RSD) of 1.4-4.7%. We successfully detected and quantified H2 in the headspaces of vacuum blood-collection tubes containing whole blood from 11 deceased individuals with several causes of death by employing the developed GC-SIM-MS method. The quantitative value of H2 ranged from 5 to 905 ppm. The proposed GC-SIM-MS method was applicable to the quantitative assay of H2 in biological samples without tedious pretreatment requirements.