Rapid Quantification of Endogenous Steroids in Human Serum Using Leidenfrost Effect-Assisted Thermal Desorption Atmospheric Pressure Photoionization Orbitrap Mass Spectrometry

Abstract

Unconjugated sex steroids in human serum play a crucial role in physiological and pathological studies and are frequently considered as biomarkers in clinical diagnosis. Because of their low polarity, poor volatility, and low concentration, the rapid and highly sensitive analysis of sex steroids in real serum matrix by ambient mass spectrometry is still challenging. Here, Leidenfrost effect-assisted thermal desorption atmospheric pressure photoionization orbitrap mass spectrometry (LETD-APPI-MS) was developed and applied to quantify free sex steroids in human serum without derivatization and chromatography separation within a few minutes. The concentration of target analyte could be increased by approximately two orders during the LETD process. The limit of quantifications and detections of endogenous sex steroids in human serum were measured at the ppt level. In contrast with commonly used immunoassays in clinical laboratories, LETD-APPI-MS enables the accurate measurements of multiple free sex steroids without the interference of cross-reactions. The endogenous sex steroids of 38 female serums at four physiological stages during pregnancy were rapidly tested by LETD-APPI-MS, whose results were highly consistent with that using liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC-APCI-MS), indicating LETD-APPI-MS has a strong clinical application potential in steroid analysis.

Improving the Sensitivity and Linear Range of Photoionization Ion Mobility Spectrometry via Confining the Ion Recombination and Space Charge Effects Assisted by Theoretical Modeling

“…1 It produces no or very few fragment ions and demonstrates high sensitivity for unsaturated aromatic compounds. 2,3 With the development of commercial compact vacuum ultraviolet (VUV) light sources, like 10.6 eV VUV Kr lamps, PI hyphenated to ion mobility spectrometry (IMS) or mass spectrometry (MS) has been widely employed in various on-site analysis fields such as clinical diagnosis, 4,5 food quality control, 6,7 environmental pollutant monitoring, 8,9 and national security. 10,11 Sensitivity and linear dynamic range are key parameters for evaluating the performance of analytical instruments.…”

“…Photoionization (PI) is an efficient ionization technique that can ionize a wide range of volatile organic compounds (VOCs) with ionization energy lower than the photon energy . It produces no or very few fragment ions and demonstrates high sensitivity for unsaturated aromatic compounds. , With the development of commercial compact vacuum ultraviolet (VUV) light sources, like 10.6 eV VUV Kr lamps, PI hyphenated to ion mobility spectrometry (IMS) or mass spectrometry (MS) has been widely employed in various on-site analysis fields such as clinical diagnosis, , food quality control, , environmental pollutant monitoring, , and national security. , …”

Nanoliter atmospheric pressure photoionization-mass spectrometry for direct bioanalysis of polycyclic aromatic hydrocarbons

“…Pan et al combined Leidenfrost effect-assisted thermal desorption (LETD) with atmospheric pressure photoionization (APPI) to quantify free sex steroids in human serum. 25 The limits of quantification (LOQs) and detection (LODs) of endogenous sex steroids in human serum were measured at the parts-per-trillion ( ppt) level. Kostiainen et al proposed infrared laser ablation atmospheric pressure photoionization mass spectrometry (LAAPPIMS) for the imaging analysis of Arabidopsis thaliana, realizing a 70 μm lateral resolution.…”