Abstract: The trace lead content of gasoline, specifically in lead concentrations of about 0.01 to 0.10 grams of lead per U.S. gallon of gasoline, is determined colorimetrically by the steps of mixing an iodine solution with the gasoline, subjecting the mixture to ultra-violet light and adding an indicator solution containing 4-(2-pyridylazo)-resorcinol disodium salt with agitation and comparing the resulting color to standard indicator solutions.

Abstract: Oxidation catalysts containing platinum or other noble metal components used in automobile exhaust emission control are reactivated, after thermal deactivation, by subjecting the catalyst to a halogen-containing gas at a temperature of from 500.degree.F. to about 1000.degree.F. The passing of carbonyl halide or a mixture of carbon monoxide and halogen, alone or in a carrier gas, over the catalyst reduces the CO-oxidation and hydrocarbon-oxidation temperature to almost that of fresh catalyst. Carbonyl chloride or the carbon monoxide-chlorine mixture is preferred. This treatment may also be used in the reactivation of noble metal-containing reforming catalysts.

Abstract: Multiple metal complexes of nitrogen compounds are prepared by reacting in any desired order (1) an organic reactant, preferably an alkenylsuccinic acid or anhydride or a polyalkylphenol-aldehyde reaction mixture, or a halogenated polyolefin; (2) a polyamine, having one nitrogen atom reactive with the organic reactant and at least one additional nitrogen atom such as an ethylene polyamine and the imidazoline or imidazolidine derivative thereof; (3) and at least two metal compounds, one of which is a metal of Groups IB, IIB, IVA, IVB, VIB, VIIB or VIII of the Periodic Table, capable of both forming a coordinated complex of the Werner type with the polyamine and also forming a complex with the second metal compound, and the said metal compound of metals of the above groups plus alkali and alkaline earth metals. The reactants may be reacted in any order, such as the above order, or the amine reactant may be precomplexed.

Abstract: Alkyl lactone esters or sulfidic esters are prepared by reacting an alkenylsuccinic anhydride with an alcohol or thiol in the presence of an acid-acting catalyst. The esters are useful as dispersants or detergents in aqueous or hydrocarbon systems or they may be further reacted with amines to produce other useful additives for such systems. Esters of monohydroxy alcohols or monothiols or polyhydroxy alcohols or polythiols may be prepared and used in this invention.