SFC 的PDA检测器和FTIR光谱仪双重检测萃取留兰香油中的香芹酮

Application Note 2/4Application NotePurification of Carvone in Spearmint Oil Purification of Carvone in Spearmint Oil using SFC with PDA andFTIR Dual-Monitoring Terpenes in essential oils are easily oxidizedand can cause a decrease in the flavor in foodsRemoval of Terpenes is commonly practicedin perfume industry to yield higher quality oils.Natural spearmint oilcontains I-limonene thatis quite unlike d-limonene， the aroma is notreminiscent of citrus but of a light， clean Terpenehydrocarbon fragrance. Conventionally， Terpenesare removed using vacuum distillation. However，it is difficult to monitor the fractionation processin real-time during this process. We used SFC with a PDA detector and anFTIR spectrometer as a dual monitoring systemto enable selective monitoring of the targetcompound Carvone in real time during elutionand fractionation. The PDA provides broadinformation on the separation， but cannotdifferentiate between limonene and Carvone. Keyword： Terpenes， essential oil purification， Spearmint Oil，Limonene， Carvone， CO2， SFC， FTIR， Enrichment HPLC-FTIR Figure 1. Structures of Carvone and Limonene. d-carvone ispresent in caraway oil while l-carvone is present in spearmint oil.They are easily differentiated by the nose.d-limonene is presentin citrus oils while I-limonene is present in spearmint oil， pine oil， etc.It is desirable to remove l-limonene from spearmint oil. Figure 2. UV and IR Spectra of Limonene and Carvone Standards. Figure 2， Limonene and Carvone have very similar UV spectra， but show differences in the IR. Co-elutionin the chromatogram detected using UV as shown in figure 3 and 4 illustrates the inability of using UV totrigger fraction collection. Figure 5 shows IR chromatograms at two different wave number ranges and the fractions collected usingthose chromatograms. A Carvone standard and Spearmint oil were separated using HPLC and fractions 1and 2 were compared to confirm the separation and purity as seen in Figure 6. SFC Conditions CO2 Flow rate： Figure 3. PDA Contour Plot of Spearmint Oil. The PDA could not differentiate limonene from carvone due to apparent co-elution.Therefore fraction timing could not be set based on the PDA. Figure 4. SFC Chromatograms of Spearmint Oil by PDA Detection. ( Application Library： http：//www.jascoinc.com/applications ) Figure 5. IR Chromatogram of Spearmint Oil used for Fractionation. Figure 6. HPLC Chromatograms. HPLC Conditions： Column： Crestpak C18S， Mobile Phase： CH3CN/H2O 60/40Flow rate： 1.0mL/min， Column Temperature： 40°C. Conclusions The carvone content in the original spearmint oil (62.7%) was successfully enriched to 89.1%. During thefractionation process the limonene peak was clearly detected using FTIR and was easily removed asfraction 1. HPLC was used to analyze the purity of the two fractions and confirmed the removal limonenefrom the spearmint oil. Application Library： http：//www.jascoinc.com/applications JASCO INC.Mary’s Court， Easton， MD USATel： ( Fax：( pplication Library： http：//www.jascoinc.com/applications