ISSN:
1040-7685
Keywords:
caffeine
;
coffee
;
micellar electrokinetic capillary chromatography (MECC)
;
reproducibility
;
HPLC
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Samples of regular and decaffeinated varieties of green coffee beans, instant coffee, and “roast & grind” coffee have been examined by micellar electrokinetic capillary chromatography (MECC). The separation conditions affecting the reproducibility of the determination of caffeine in these samples are presented. Sodium dodecyl sulfate (SDS) and cetyltrimethylammonium chloride (CTAC) Were employed to demonstrate the role of the surfactant system in reproducibility. The use of NaOH and HCl was explored for column rinsing to enhance the stability of the electroosmotic flow. The levels of caffeine ranged from 3.95% (by weight) for regular coffee to 0.07% for decaffeinated coffee. The relative standard deviation (RSD) for the migration time of the peak corresponding to caffeine in coffee samples was 0.74%. The RSDs for the peak areas and heights were 1.04 and 2.07%, respectively. The results of the quantitation of caffeine by MECC are compared to levels determined by high-performance liquid chromatography (HPLC).
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mcs.1220060103
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