Optimization and validation of a head space solid-phase microextraction-arrow gas chromatography-mass spectrometry method using central composite design for determination of aroma compounds in Chinese liquor (Baijiu).

A headspace solid-phase microextraction Arrow (HS-SPME Arrow) method coupled with gas chromatography-mass spectrometry (GC-MS) was developed for the quantitation of a large number of aroma compounds in Chinese liquor (Baijiu). Optimization of extraction conditions by a central composite experimental design revealed that the dilution of the alcohol content of 5 mL of Baijiu to 10%, followed by the addition of 1.5 g of NaCl and subsequent SPME Arrow extraction with DVB/CAR/PDMS fiber coating over 45 min at 45 °C was the most suitable. The quantitative method allowed the extraction and identification of 82 aroma compounds (esters, alcohols, fatty acids, aldehydes & ketones, furans, pyrazines, sulfur compounds, phenols, terpenes, and lactones) in the Baijiu sample. The method was validated with good repeatability, inter and intra-day precision (almost below 15%), and accuracy (almost in the range of 81.5-119.96%). Furthermore, the method was validated successfully for the most significant compounds and was applied to study the composition of volatile compounds in different types of Baijiu. This research proved that SPME Arrow is an effective method for the extraction of aroma compounds in Baijiu and other distilled spirits. This developed method will allow improved analysis of other distilled spirits.