Reducing the background interference of liquid-liquid extraction method during Baijiu aroma analysis

Area of Science:

• Analytical Chemistry
• Food Science

Background:

• Liquid-liquid extraction (LLE) is crucial for Baijiu aroma analysis using gas chromatography-mass spectrometry (GC/MS).
• Background contamination from LLE, however, is poorly understood and can interfere with accurate analysis.
• Ghost peaks, particularly 2,4-di-tert-butylphenol (2,4-DTBP), have been observed in traditional LLE-GC/MS analyses of synthetic Baijiu.

Purpose of the Study:

• To investigate and identify the sources of background problems in LLE-GC/MS analysis of Baijiu.
• To determine the origin of ghost peaks, specifically 2,4-DTBP, observed during Baijiu aroma profiling.
• To develop effective strategies for mitigating LLE-induced background contamination.

Main Methods:

• Analysis of synthetic Baijiu using traditional LLE-GC/MS.
• Single-factor experiments to identify contaminant sources.
• Evaluation of high-temperature baking as a decontamination method.
• Development of a combined strategy for background reduction.

Main Results:

• Ghost peaks, including 2,4-DTBP, palmitic acid, and oleanitrile, were detected between 47.0-60.0 min retention time.
• 2,4-DTBP was confirmed to originate from sodium sulfate and sodium chloride, not Baijiu itself.
• High-temperature baking proved effective in eliminating these interfering compounds.
• A combined strategy of standard cleaning and high-temperature baking was proposed.

Conclusions:

• LLE-GC/MS analysis of Baijiu is susceptible to background contamination from inorganic salts.
• High-temperature baking is a viable method to remove contaminants like 2,4-DTBP.
• The proposed combined strategy enhances the reliability of Baijiu aroma analysis and allows for the identification of more trace compounds.