Determination of Caffeine level in Coffee and Artemisinin in Artemisia annua
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Date
2009-07
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Addis Ababa Universty
Abstract
Coffee is the second important raw material within the international trade, the
most important foreign exchange supplier for many agricultural oriented
countries, and the most popular drink. Assessment of the caffeine level is crucial
to coffee quality.
An HPLC-UV method with microwave assisted extraction was developed, which
allowed the determination of caffeine in green, roasted, home-and coffee-house
brewed coffee samples. The chromatographic separation was achieved on
reversed-phase C-18 pre-packed analytical column (RP-18 Lichrospher®,
Waters, 5μm, 4.6 X 150 mm i.d.) using water: Acetonitrile (70:30, v/v) as isocratic
mobile phase at 0.8 mL/min flow rate. The method has been applied to samples
to afford average caffeine contents (0.8-1.0%) green and roasted, (48-102 mg)
home- brewed, (24-56%) coffee-house brewed. The overall procedure had
percent recoveries of 93%. The within day and between day percent RSD in
coffee samples ranged from 2.4-6 and 0.8-14%, respectively. HPLC-UV is a
method used for caffeine routine analysis.
Artemisia annua is the only commercial source of artemisinin. Due to the
absence of appropriate UV absorption, artemisinin should be converted into UV
active compound before HPLC analysis. It can be analyzed using Quantitative
TLC method with anisaldehyde visualization reagent
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Coffee and Artemisinin in Artemisia annua