Lab-made solid phase microextraction phases for off line extraction and direct mass spectrometry analysis: Evaluating...

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Materials Science

Background:

• Analysis of drugs and metabolites in complex matrices is challenging due to endogenous compounds and matrix complexity.
• Traditional methods often require extensive sample pre-treatment steps.
• Direct analysis techniques are desirable for simplified workflows.

Purpose of the Study:

• To develop and evaluate two lab-made extractive phases for direct analysis using probe electrospray ionization mass spectrometry (PESI-MS).
• To assess the applicability of these phases for analyzing illicit drugs in biological fluids and phorbol esters in plant extracts.
• To provide sensitive and accurate analytical methods for complex sample matrices.

Main Methods:

• Electropolymerization of polypyrrole (PPy) onto a platinum wire using cyclic voltammetry.
• Synthesis of a molecularly imprinted polymer (MIP) adhered onto a stainless-steel needle.
• Integration of PPy and MIP phases with PESI-MS for direct sample analysis.
• Validation of analytical methods for linearity, accuracy, and precision.

Main Results:

• The PPy-PESI-MS method demonstrated linearity from 1 to 500 μg L⁻¹, with accuracy between -2.1% and 14%, and precision between 0.8% and 10.8%.
• The MIP-PESI-MS method showed linearity from 0.9 to 30 mg L⁻¹, with accuracy between -1.6% and -15.3%, and precision between 4.1% and 13.5%.
• Both methods proved effective for direct analysis in complex matrices, reducing sample preparation needs.

Conclusions:

• Lab-made PPy and MIP extractive phases are effective for direct analysis via PESI-MS.
• These methods offer viable solutions for analyzing drugs in biological fluids and phorbol esters in plant extracts.
• The developed PESI-MS approaches simplify sample analysis and improve efficiency.