Shell Oil Company, Woo~l River Research Laboratory. Wood River. Illinois Qualttat,,~e and qttanti~ati'~e analyses have been made of the more stab/e reectlon products of clear and k:ad~ t~0b. <~ctanc t;~med in a motored, single-cylinder" CFR en$ine. By varying the compf~ton ratio (CR) of tEr-emllli~. oxidative t,:actions could be followed from iniua| reaction to incipient autoignition. Cool flam~ ~tm~utt~ or" the fuels were followed and peak cycle prยข:,sures were measured. Techniques we.re developed to oMte~ telmmt~, mc~sure and identif~ the comlMeX mixtures of reaction products. The combination ofcapilhLry gas,-4iquid cttmm~t~-
โข gr~tphy (GLC) and timยข-~f-flight mass spetnrometry proved to be particularly veluetble in idemt0/it~ minor products. Twenty compounds were identified, accounting for approximately 95% w of the l~rMt~ct~ tsobutene, the isomers of diisob~tyiene, two Cs cyclic ethers, and a Cs aldehyde were lhe predomma~ intermediates detected. Tetraethyliead f~EL~ markedly red.ueed the intensity of the tool flame ~ a~L m general, inhibited, the degradation of isooctnr e at all severity levels stnd;ed. At incipient autoigttitiorL TEL r~lmmd the concentration iper unit volume} of detet:t~x~ peroxides to a significantly gre~tter extent than troy o4tlb~ peoat~ ยขit ciass of prodt~cts measured. Thus, the mare aclion of TEL appears to be the deactivation of peroxide, a~l petrmqยข chf in-branching mterraed~tes.