ABSTRACT
ObjectiveTo compare the effects of different drying methods on volatile components of Pseudostellariae Radix. MethodThe samples were dried by different methods， including air drying， sun drying， hot air drying （40， 60， 80 ℃） and vacuum freeze drying. Gas chromatography-ion mobility spectrometry （GC-IMS） was used to compare the changes of volatile components in the samples after different treatments. The samples were incubated at 80 ℃ and 500 r·min-1 for 15 min， the injection temperature was 85 ℃， the injection volume was 200 μL， the flow rate of carrier gas was from 2 mL to 150 mL during 20 min， and the temperature of IMS detector was 60 ℃. SE-54 capillary column （0.32 mm×30 m， 0.25 μm） was used， the column temperature was 60 ℃， and the analysis time was 35 min. The differential spectra of volatile components were constructed and analyzed by principal component analysis （PCA）. ResultA total of 37 volatile components were identified from dried Pseudostellariae Radix. The number of compounds in descending order was ketones， aldehydes and alcohols. There were some differences in the volatile components in samples dried by different methods. And the volatile components in samples with sun drying， air drying and hot air drying at 40 ℃ were similar， compared with other drying methods， vacuum freeze drying and hot air drying at 80 ℃ had great effects on the volatile components of Pseudostellariae Radix， and the compounds in the samples with vacuum freeze drying were the least. ConclusionIn this study， GC-IMS for the detection and analysis of volatile components in Pseudostellariae Radix is established， which has the characteristics of high efficiency， nondestructive inspection and simple sample processing. This method can be used for the distinction of Pseudostellariae Radix dried by different methods. And hot air drying at 40 ℃ can effectively retain the volatile components of Pseudostellariae Radix， and achieve similar flavor to samples with sun drying and air drying.