Improved sample pre-treatment for determination of caffeine in tea using a cartridge filled with polyvinylpolypyrroridone (PVPP).
We have improved sample pre-treatment for the effective removal of polyphenols and simple analysis of caffeine in tea using a cartridge filled with polyvinylpolypyrroridone (PVPP). Nearly 100% of catechins were removed from the green tea sample and caffeine was completely recovered in the range of 98.2-101.3% by sample pre-treatment with a PVPP cartridge. Reproducibility of preparing PVPP pre-treatment cartridges was sufficient for quantitative analysis, because RSDs of analytical values for caffeine obtained by using three individual pre-treatment cartridges filled with 10-200 mg PVPP were 0.60-2.8%. The PVPP pre-treatment cartridge also removed polyphenols perfectly and recovered caffeine faultlessly from oolong and black tea samples. Comparison with the conventional method without sample pre-treatment indicated that the present pre-treatment method with a PVPP cartridge was useful for the simple and precise analysis of caffeine in green, oolong and black tea samples.
Yamauchi
Yuji
Y
Faculty of Pharmaceutical Sciences, Doshisha Women's University, Kyoto, Japan.
Nakamura
Akiko
A
Kitai
Miki
M
Hatanaka
Kirara
K
Kohno
Iho
I
Tanimoto
Tsuyoshi
T
D002110:Caffeine / Q000032:analysis*; D002392:Catechin / Q000032:analysis; D000697:Central Nervous System Stimulants / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D011205:Povidone / Q000031:analogs & derivatives* / Q000032:analysis; D013662:Tea / Q000737:chemistry*