High sensitivity steroid analysis using liquid chromatography/solvent-assisted inlet ionization mass spectrometry

Area of Science:

• Analytical Chemistry
• Biochemistry
• Forensic Science

Background:

• Steroids are used therapeutically for muscle growth but raise concerns regarding synthetic forms in food and athlete doping.
• Accurate detection of steroids is crucial for consumer safety and anti-doping efforts.
• Existing analytical methods require improvement in sensitivity and efficiency.

Purpose of the Study:

• To introduce and validate a novel ionization technique for enhanced steroid detection.
• To assess the sensitivity and quantitation limits of the new method for steroid analysis.
• To compare the performance of the new method against established ionization techniques.

Main Methods:

• Solvent-assisted inlet ionization (SAII) mass spectrometry was directly coupled with liquid chromatography (LC/MS).
• High-resolution accurate mass data were acquired using Orbitrap and QTOF mass spectrometers.
• Limits of detection and quantitation were determined for selected steroids in various matrices.

Main Results:

• SAII demonstrated very low limits of detection (low ppqt) and quantitation (low ppt) for steroids.
• Sensitive detection (low ppb) was achieved in spiked urine samples with minimal sample preparation.
• The method provided high signal-to-noise ratios, indicating robust performance.

Conclusions:

• Liquid chromatography coupled with solvent-assisted inlet ionization mass spectrometry (LC/SAII-MS) offers superior sensitivity compared to electrospray ionization (ESI) for steroid analysis.
• LC/SAII-MS has previously shown high sensitivity for peptide analysis.
• This easily implemented ionization method presents a promising alternative to ESI for diverse analytical applications.