Food Chemistry 42 (1991) 81-87 ! Simultaneous Determination of Total Chlorogenic Acid and Caffeine in Coffee by High Performance Gel Filtration Chromatography L. C. Trugo, C. A. B. De Maria & C. C. Werneck Department of Biochemistry, Institute of Chemistry, Universidade Federal do Rio de Janeiro, C. T. bloco A, Cidade Universitaria, 21944 Rio de Janeiro, Brazil (Received 24 August 1990; accepted 24 September 1990) ABSTRACT A method based on high performance gelfiltration chromatograph),, using a TSK 3000-S W column, was developed for the simultaneous determination of total chlorogenic acid and caffeine in coffee samples. The method presented good linearities and recoveries Jbr both compounds. Comparison with results obtained by reversed phase chromatography for caffeine and by the A OA C procedure and an adapted reversed phase chromatographic method .]'or chlorogenic acid showed good correlations between the proposed method and the reversed phase procedures (0"997for caffeine and 0"998for chlorogenic acid). The A OA C results for chlorogenic acid showed systematically higher values than the proposed method. The proposed method gave a C V( % ) of 6.5 for caffeine and 5"O for chlorogenic acid and is adequate when applied to the analysis of different samples of green, roasted decaffeinated and instant coffees. INTRODUCTION Monitoring of caffeine in coffee is of importance particularly for the coffee industry, not only for assessing caffeine level in green coffee beans before processing, but also to determine the final content in coffee products. Several methods have been used for the determination of caffeine mainly based on spectrophotometry (Newton, 1979), gas chromatography (Schilling & Gal, 1973; Strahl et aL, 1977; Hughes & Thorpe, 1987; Rauch et al., 1989) or high 81 Food Chemistry 0308-8146/91/$03"50 © 1991 Elsevier Science Publishers Ltd, England. Printed in Great Britain