Thermo Fisher Scientific announced a new approach using high-performance anion-exchange (HPAE) chromatography with pulsed amperometric detection (PAD) for the determination of carbohydrates in extracts from instant coffee and green coffee beans. Application Note 280: "Carbohydrate in Coffee: AOAC Method 995.13 vs a New Fast Ion Chromatography Method" compares two methods: the Association of Analytical Chemists ( AOAC) official method 995.13 and a fast method using the CarboPac ™ SA10 column . The former method has a longer run time (80 minutes) compared to the fast method (10 minutes). For certain sugars that may be difficult to resolve with the official method, minor modifications are suggested. The fast method, proposed for analyzing coffee carbohydrates, resolves 7 of the 11 coffee carbohydrates in 8 minutes and needs only the addition of deionized water for continuous operation.
Both methods have high precision and acceptable recovery for the carbohydrates in instant and green coffee extracts. In addition, disposable gold working electrodes provide consistently high detector response for both methods, assuring greater instrument-to-instrument and lab-to-lab reproducibility. In summary, both the AOAC official method 995.13 and the fast method are sensitive, accurate, reliable, and differ primarily in their total analysis time and peak resolutions for coffee carbohydrate determinations.