The Analysis of Lead Antiknock Additives by Gas Chromatography

Electron transfer with organometals. Steric effects as probes for outer-sphere and inner-sphere oxidations of homoleptic alkylmetals with iron(III) and iridate(IV) complexes

“…Tetraethyllead was a gift from Ethyl Corp. and was purified by steam distillation followed by fractional vacuum distillation. Tetramethyllead was prepared according to Gilman and Jones.56 Diethyldimethyllead was synthesized from diethyllead diacetate and methylmagnesium iodide in tetrahydrofuran.9a The methylethyllead compounds were analyzed by gas-liquid chromatography, being resolved on a 4-ft column containing 10% polyethylene glycol 600/1% Quadrol supported on Chromosorb W. 57 All the symmetrical tetraalkyltin compounds (i.e., RaSn) were prepared by the standard reaction between anhydrous stannic chloride and the corresponding alkyl Grignard reagent in either diethyl ether or di-zi-butyl ether as solvent.56 The unsymmetrical tetraalkyltin compounds (SnR"R'4 -) were prepared from the appropriate alkylchlorotin compound (SnR"Cl4 -n) and the alkyl Grignard reagent (R'MgX) or vice versa.56 Tetraethylsilane and tetraethylgermane were prepared by an analogous procedure from ethylmagnesium bromide and tetrachlorosilane and tetrachlorogermane, respectively.…”

Determination of tetraalkyllead compounds in gasoline by liquid chromatography-atomic absorption spectrometry

“…Parker et al (6) initially sepa- 1 Present address: U.S. Geological Survey, 923 National Center, Reston, VA 22092. rated all five TAL compounds by isothermal gas chromatography (GC), collected them individually in methanolic iodide scrubbers as they eluted from the column, and then measured the total lead content in each fraction by a dithizone spectrophotometric procedure. This lengthy and complex procedure was improved by gas chromatographic techniques which incorporated on-line electron capture (7)(8)(9), catalytic hydrogenation prederivatization flame ionization (10)(11)(12), and hot-wire thermal conductivity (12) detection systems. However, interferences due to coeluting gasoline matrix constituents frequently plaqued the unambiguous detection of all five TAL compounds using such coventional detectors.…”