Screening of volatile compounds in honey using a new sampling strategy combining multiple extraction temperatures in a single assay by HS-SPME-GC-MS

Abstract

This paper proposes a new optimization strategy for the extraction of volatile compounds from honey samples using headspace solid-phase microextraction (HS-SPME) and separation/detection by gas chromatography-mass spectrometry (GC-MS). The new optimization strategy was based on the use of three different extraction temperatures in a single assay, aiming at extracting a high number of compounds with wide range of volatilities. As an analytical tool, experimental designs were used for the optimization. The variables extraction time (10-80 min), extraction temperature (0-60 °C), water volume (0.5-5 mL) and percentage of sodium chloride saturation in water (0-100%) were optimised using a five-level fractional central composite design with CAR/DVB/PDMS fibre. The final optimised combination of extraction times at each temperature was 60 min with the sample temperature being held at 60 °C for 36 min, 40 °C for 18 min and 0 °C for 6 min. The proposed method was compared to conventional methods which employ one or two extraction temperatures. It was found that the proposed method presented better results considering the response in terms of the arithmetic means of the peak areas. The use of multiple extraction temperatures for the HS-SPME procedure proved to be an excellent alternative for the screening of compounds present in honey with a wide range of volatilities.

Keywords: HS-SPME; Honey; Multiple extraction temperatures; Multivariate optimization.