Phenolic compounds determination in stingless bee by dispersive liquid-liquid microextraction coupled with capillary...

Area of Science:

• Analytical Chemistry
• Environmental Chemistry
• Food Chemistry

Background:

• Phenolic compounds (PCs) are vital antioxidants found in honey, but their accurate quantification requires efficient extraction and sensitive detection methods.
• Existing methods for PC analysis can be complex and environmentally taxing.
• Stingless bee honey (SBH) is a rich source of bioactive compounds, necessitating robust analytical techniques for its characterization.

Purpose of the Study:

• To develop and validate a novel dispersive liquid-liquid microextraction (DLLME) coupled with capillary electrophoresis-diode array detection (CE-DAD) method.
• To optimize DLLME conditions for efficient extraction of sixteen phenolic compounds.
• To apply the validated method for the determination of phenolic compounds in Tualang and stingless bee honey.

Main Methods:

• Dispersive liquid-liquid microextraction (DLLME) using ethyl acetate and acetonitrile as solvents.
• Capillary electrophoresis (CE) separation using a fused-silica capillary and a borax buffer (40 mmol L^-1, pH 9.3) with 10% ethanol.
• Diode array detection (DAD) with optimized voltage (20 kV), temperature (25 °C), and hydrodynamic injection (30 mbar for 6 s).

Main Results:

• The DLLME-CE-DAD method successfully separated sixteen phenolic compounds within 32 minutes.
• Linear calibration curves (r² > 0.998) were achieved for PCs in the range of 0.3-20 mg L^-1.
• The method demonstrated good recoveries (85.2-110.7%), low detection limits (0.01-0.52 mg L^-1), and acceptable precision (RSD ≤ 5.66%).
• The method achieved favorable greenness scores (AGREEprep: 0.35, AGREE: 0.54).

Conclusions:

• The developed DLLME-CE-DAD method is a simple, sensitive, and environmentally friendly technique for quantifying phenolic compounds.
• The method is suitable for the analysis of phenolic compounds in complex matrices like stingless bee honey.
• This approach offers a valuable tool for quality control and research involving honey products.