Factors affecting the desorption of organic analytes from activated carbon (7440440) were investigated, using a statistical design employing a two level factorial protocol. Loading of the sorbent per 100 milligrams charcoal, volume of the desorbent agent, and the presence or absence of compounds other than the analyte were examined. Carbon-disulfide (75150) (CS2) was used as the desorbent. Test analytes were 2-ethoxyethyl-acetate (111159) (cellosolve- acetate), 2-butoxyethanol (111762) (butyl-cellosolve), n-butanol (71363), toluene (108883), and biphenyl (92524). Mixture tested consisted of a polar mixture containing cellosolve-acetate, butyl- cellosolve, n-butanol, and toluene; a mixture of a polar and nonpolar compound of cellosolve-acetate and biphenyl; and a mixture of two nonpolar compounds containing biphenyl and toluene. All factors were tested at a high and a low range. Desorption efficiencies were: 100 percent for toluene; 47 to 92 percent for butanol; 53 to 103 for cellosolve-acetate in the polar mixture experiment and 53 to 97 percent in the polar/nonpolar experiment; 12 to 77 percent for butyl-cellosolve; and 58 to 92 percent for biphenyl. For nonpolar compounds and for a mixture of a polar and nonpolar compound, no effect was observed for the presence of any one compound in the mixture on the desorption efficiency of the others. For polar compounds a dependency was seen on the presence of other compounds. The authors suggest that an adequate explanation of all the main effects and interactions, including the signs of the latter, can be advanced on equilibrium grounds.