1. An analyst measured the concentration of caffeine in a cup of espresso from Dunkin(sample D) and from Starbucks (sample S). Since he used different HPLC machines to run the measurements, he added 0.1 mM theobromine to each sample as internal standard. The results of his work are presented below. Based on the Analyst’s results, estimate [Caffeine]D/[Caffeine]S.
(a) 0.625
(b) 1.250
(c) 1.875
(d) 2.875