3.1. Pure substance RM (caffeine)
In order to ensure extraction of caffeine from roasted coffee, a sample of the standard caffeine purchased from Alfa Aesar and a sample of the extracted caffeine were run on the HPLC system and the UV/Vis spectrophotometer under the same conditions. The produced HPLC chromatograms of both samples are shown in Figure 1, Figure 2, and the absorbance peaks produced by the spectrophotometer are shown in Figure 3, Figure 4. From Figure 1, Figure 2, it is clear that the peaks of the two samples appear at the same retention time (1.75 minutes), and from Figure 3, Figure 4 we can also see that the two absorption peaks appear at 273±1 nm. This clearly assures the extraction of caffeine from roasted coffee. The extract was then purified on a silica gel column and dried. The whole purified caffeine RM was bottled in 25 vials, each containing 0.2 g. Stratified random selection was applied to select five vials for homogeneity study and for certification of the caffeine purity %.
3.1. Pure substance RM (caffeine)In order to ensure extraction of caffeine from roasted coffee, a sample of the standard caffeine purchased from Alfa Aesar and a sample of the extracted caffeine were run on the HPLC system and the UV/Vis spectrophotometer under the same conditions. The produced HPLC chromatograms of both samples are shown in Figure 1, Figure 2, and the absorbance peaks produced by the spectrophotometer are shown in Figure 3, Figure 4. From Figure 1, Figure 2, it is clear that the peaks of the two samples appear at the same retention time (1.75 minutes), and from Figure 3, Figure 4 we can also see that the two absorption peaks appear at 273±1 nm. This clearly assures the extraction of caffeine from roasted coffee. The extract was then purified on a silica gel column and dried. The whole purified caffeine RM was bottled in 25 vials, each containing 0.2 g. Stratified random selection was applied to select five vials for homogeneity study and for certification of the caffeine purity %.
การแปล กรุณารอสักครู่..
