Profiling Multiple Steroid Subclasses Enabled by Rounded Turn SLIM Ion Mobility.

Area of Science:

• Analytical Chemistry
• Biochemistry
• Spectrometry

Background:

• Ion mobility-mass spectrometry (IM-MS) is crucial for steroid analysis, offering speed and separation of complex mixtures.
• High-resolution ion mobility (HRIM) techniques are increasingly used in steroidomics, but challenges remain for low molecular weight compounds.
• Structures for Lossless Ion Manipulations (SLIM) is an emerging HRIM technique with potential for steroid analysis.

Purpose of the Study:

• To evaluate a novel, low mass-tailored SLIM system for analyzing various steroid subclasses.
• To assess the system's performance in separating challenging steroid isomers.
• To compare the efficiency of the new SLIM platform with traditional designs.

Main Methods:

• Utilized a low mass-tailored SLIM platform with rounded turns, helium buffer gas, and increased RF frequency.
• Determined collision cross section (CCS) values and compared them with drift tube measurements.
• Evaluated separation performance for isomers with small differences in CCS.
• Quantitatively compared rounded turn SLIM with 90° turn SLIM using nitrogen and helium.

Main Results:

• Linear regression-corrected SLIM CCS values showed excellent agreement with drift tube data, highlighting the need for class-specific correction factors.
• The system achieved good resolution for isomers with ΔCCS <1%.
• Rounded turn SLIM with helium buffer gas significantly improved signal compared to traditional systems and nitrogen buffer gas.

Conclusions:

• The low mass-tailored SLIM system demonstrates significant promise for rapid and targeted steroid analysis.
• The optimized SLIM platform enhances the analysis of low molecular weight steroids, including anabolic androgens, bile acids, and hormones.
• This technology has broad applicability in biomedical, clinical, food, environmental, and antidoping fields.