Determination of Puberulic Acid in Monascus-Fermented Red Yeast Rice by LC-MS/MS Combined with Precolumn...

Area of Science:

• Analytical Chemistry
• Food Safety
• Mycotoxicology

Background:

• Puberulic acid (PA) is a mycotoxin linked to fatalities from red yeast rice supplements.
• Detecting low concentrations of PA presents a significant analytical challenge.

Purpose of the Study:

• To develop a simple, sensitive, and rapid method for puberulic acid detection in red yeast rice.
• To establish a reliable analytical technique for assessing PA contamination in dietary supplements.

Main Methods:

• A derivatization-based liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed.
• Methylating derivatization using trimethylsilyldiazomethane (TMSCHN2) enhanced analytical performance.
• Method parameters including solvent, reagent amounts, and reaction time were optimized for sensitivity.

Main Results:

• The LC-MS/MS method demonstrated over 100-fold higher sensitivity compared to traditional liquid chromatography.
• Excellent linearity (R²=0.99952), recovery (82.2-84.2%), and repeatability (RSD 2.1-10.4%) were achieved.
• The method achieved limits of detection and quantification of 2 µg/kg and 50 µg/kg, respectively.

Conclusions:

• The developed LC-MS/MS method is highly sensitive and suitable for routine analysis of PA in red yeast rice.
• Analysis of 42 batches of red yeast rice indicated a low risk of PA contamination in products from China.
• The method's applicability was confirmed for other health food products containing red yeast rice.