Capillary-in-Capillary Electrospray Ionization (CC-ESI) Source Enabling Convenient Sampling and Quantitative Analysis...

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Clinical Diagnostics

Background:

• Mass spectrometry (MS) offers high analytical performance for clinical applications.
• Existing sampling and ionization methods can be complex and costly.
• There is a need for simplified, portable MS interfaces for clinical analysis.

Purpose of the Study:

• To develop a novel capillary-in-capillary electrospray ionization (CC-ESI) source.
• To enable spontaneous liquid sampling and direct electrospray ionization mass spectrometry (ESI-MS) analysis.
• To assess the performance of the CC-ESI source coupled with a miniature mass spectrometer (mini-MS) for clinical applications.

Main Methods:

• Fabrication of a capillary-in-capillary (CC) interface for simultaneous sampling and ESI.
• Coupling the CC-ESI source with a miniature mass spectrometer (mini-MS).
• Performance evaluation using standard drug analytes (imatinib, atenolol) in various MS modes (CID, MRM).

Main Results:

• The CC-ESI source demonstrated a limit of detection (LOD) of 1 ng/mL for imatinib in CID tandem MS mode.
• A limit of quantification (LOQ) of 1 ng/mL was achieved for atenolol and imatinib using MRM.
• Successful rapid analysis of abused drugs on surfaces and quantitative analysis of therapeutic drugs in whole blood were demonstrated.

Conclusions:

• The developed CC-ESI source is a low-cost, portable, and disposable tool for ESI-MS.
• It offers good quantitation capability and adequate sensitivity for clinical sample analysis.
• The CC-ESI mini-MS system provides a promising platform for rapid and sensitive clinical diagnostics.