Sterol analysis in cancer cells using atmospheric pressure ionization techniques

Area of Science:

• Analytical Chemistry
• Biochemistry
• Mass Spectrometry

Background:

• Sterol biosynthesis analysis faces challenges like wide concentration ranges and matrix interferences causing ion suppression.
• Liquid chromatography-mass spectrometry (LC-MS) is crucial, but sensitive detection relies heavily on effective ionization techniques.

Purpose of the Study:

• To develop and evaluate a novel tube plasma ionization (TPI) source for LC-MS sterol analysis.
• To compare the performance of TPI against established electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) methods.

Main Methods:

• Development of a new tube plasma ion source for LC-MS.
• Comparative analysis of TPI, ESI, and APCI for sterol ionization efficiency and sensitivity.
• Application of the TPI source to complex biological matrices: human plasma, HepG2 cells, and liver tissue.

Main Results:

• The TPI source demonstrated comparable limits of quantitation (LOQs) to APCI and superior sensitivity compared to ESI.
• TPI and APCI provided stable signals during long measurements, unlike ESI which suffered from significant ion suppression.
• Sterol quantification results using TPI closely matched those obtained with APCI in all tested biological samples.

Conclusions:

• The novel TPI source is a sensitive and robust tool for sterol analysis in complex biological matrices.
• TPI offers a promising alternative to ESI and APCI for challenging sterol quantification workflows.
• This advancement facilitates more reliable analysis of sterol biosynthesis and related metabolic pathways.