Quantification of 4-hydroxy-2,5-dimethyl-3-furanone in fruit samples using solid phase microextraction coupled with gas chromatography–mass spectrometry

Furaneol is an important aroma compound. It is very difficult to extract furaneol from food matrices and separate it on a gas chromatography column due to its high polarity and instability. A new quantitative method was developed to quantify furaneol in aqueous samples by the use of derivatization/solid phase microextraction (SPME) coupled with gas chromatography/mass spectrometry (GC/MS). The derivatization was carried out by reacting pentafluorobenzyl bromide with furaneol in basic solutions at elevated temperatures. The derivative was stable and less polar so that SPME-GC/MS could be applied for extraction, separation and detection. The automated analytical method had a limit of detection (LOD) of 0.5 ng mL−1, a limit of quantification (LOQ) of 2 ng mL−1, a repeatability of 9.5%, and a linear range from 2 to 500 ng mL−1. The method was applied to analyze fruit samples. And it was found that the concentrations of furaneol in tomato ranged from 95 to 173 μg kg−1, in strawberries ranged from 1663 to 4852 μg kg−1. The results were verified with a LC procedure. To facilitate analytical method development, some physico-chemical parameters for furaneol were determined in this work. Its solubility in water was determined as 0.315 g mL−1 (25 °C). Its Log D in water and Log P in 0.1 M phosphate buffer were −0.133 and 0.95 (20 °C), respectively. Its pKa was 8.56 (20 °C).