With the employed chromatographic condition, a good base- line separation of individual SCFA and peak shape was obtained for a biogas digester sample with a reasonable short run time of less than 14 min (Fig. 2). As shown in Fig. 2, acetate and propionate were the main constituents of the sample. The peaks shape was sharp and well resolved even if the sample matrix was very complex as expected from organic waste treating biogas digester. These results showed that a good separation of individual SCFA could be achieved without employing the time-consuming derivatization and conventional liquid extraction techniques reported in literature [12]. It took only less than half an hour for biogas digester sample preparation and a single GC/MS run, showing the high throughput of the employed method.