Modular Point-of-Need Tropane Alkaloid Detection at Regulatory Levels: Combining Solid-Liquid Extraction from...

Area of Science:

• Analytical Chemistry
• Food Safety
• Microfluidics

Background:

• Tropane alkaloid contamination in cereals is a growing global concern.
• Existing detection methods (e.g., LC-MS) are time-consuming, expensive, and lack portability.
• Miniaturized alternatives suffer from low sensitivity and robustness, necessitating improved screening tools.

Purpose of the Study:

• To develop an inexpensive, on-site applicable modular workflow for detecting tropane alkaloids in buckwheat.
• To integrate paper microfluidics and 3D-printed sample preparation for efficient analysis.
• To enable rapid screening of contaminants like atropine and scopolamine in food matrices.

Main Methods:

• A modular workflow combining paper microfluidics and 3D-printed sample preparation tools was developed.
• Tropane alkaloids were extracted using a mixture of alkaline aqueous and organic solvents.
• Paper-immobilized liquid-phase microextraction (PI-LPME) was employed for concentration, followed by elution and detection via indirect competitive lateral flow immunoassay (icLFIA).

Main Results:

• The workflow demonstrated effective extraction (66-79%) and concentration (60-108×) of tropane alkaloids.
• Indirect competitive lateral flow immunoassay (icLFIA) enabled semi-quantification of atropine with an IC50 of 0.56 ng mL⁻¹.
• Validation in spiked buckwheat samples showed low false negative (1%) and false positive (0.68%) rates, establishing a reliable cutoff value.

Conclusions:

• The developed modular workflow provides a fast, inexpensive, and on-site solution for atropine detection in buckwheat by non-experts.
• The PI-LPME method is versatile and applicable to other compounds with pH-dependent polarity.
• Integration with scopolamine-specific icLFIA can expand the workflow's capability for broader tropane alkaloid screening.