Fig. 1. Typical gas chromatography profile of 3-mo-old compost sample extracted at basic pH and derivatized with methanol at low pH. Peaks of methyl esters of formic (1), acetic (2), propionic (3), iso-butyric (4), butyric (5), valeric (6), caproic (7), enanthoic (8), caprylic (9), pelargonic (10), and capric (11) acids are sharp, symmetric, and quantifiable.