Abstract: A method for the analysis of peroxide in hydrocarbon fuels such as jet fuels, diesel fuel, kerosene and gasoline is disclosed which can be performed both at remote locations as well as in a laboratory setting. A sample of the fuel to be tested is mixed with a solution containing a water-soluble salt and aqueous iodide solution to reduce the peroxide and produce free iodine. The sample is then subjected to a single sweep voltammetric analysis to measure the current through the sample as a function of the potential applied. The resulting peak of current on a current-potential plot can then be used to determine the amount of peroxide in solution.

Abstract: A method for analysis of freshness of fuels, food products, and oils, lubricants and other fluids, and other organic materials, is disclosed which quickly analyzes oxidative degradation of a sample off-line by measuring the oxidation products of the material. A sample of the material is dissolved and subjected to single sweep voltammetric analysis to measure the current through the sample as a function of the potential applied. The resulting current-voltage plot reflects the level of oxidation products present in the material sampled. The method results in data which can be used to evaluate the freshness of unused materials which degrade during storage, as well as to monitor deterioration of materials during use.

Abstract: A method and apparatus is disclosed for the complete analysis of used oils, lubricants, and fluids. The method can monitor antioxidant depletion, oxidation initiators buildup, product buildup, or liquid contamination or combinations thereof. The method can be performed either on-line or off-line but is preferably an on-line system, either a built-in system or a dip-stick type system, having a working microelectrode, a reference electrode, and an auxiliary electrode. A sample is contacted by the electrodes and subjected to cyclic voltammetric analysis, whereby a varying electric current is produced within the sample. The current is measured and recorded, and the conductance is measured. The remaining useful life of the oil, lubricant, or fluid is then determined from the wave heights of the oxidation and reduction peaks, and the contamination is determined from the conductance.

Abstract: A method is disclosed for measuring the remaining useful life of a hydrocarbon oil containing at least one additive species. An oil sample is mixed with a solvent, a solid substrate, and in some cases an electrolyte to produce an analysis sample. The analysis sample is placed into an electrolytic cell and subjected to a voltammetric analysis, whereby increasing potential is applied to the cell to produce an oxidation reaction and a varying electric current. The current during the voltammetric analysis is measured and recorded. Remaining useful life for the oil is then determined from the oxidation current wave height produced.

Abstract: A method is disclosed for measuring the remaining useful life of an ester-based lubricant containing at least one antioxidant species. A lubricant sample is mixed with a solvent, an organic base and an electrolyte to produce an analysis sample. The analysis sample is placed into an electrolytic cell and subjected to a cyclic voltammetric analysis, whereby a varying electric current is produced within the cell. The current during the cyclic voltammetric analysis is measured and recorded. Remaining useful life for the lubricant is then determined from the average maximum reduction current wave height produced.

Abstract: The degree of wear metal contamination in an oil is determined by treating a sample of the oil with a mixture of HF/HCl/nitric acid, diluting the oil/acid mixture with a solvent mixture consisting of a nonionic surfactant and a diluent, and spectrometrically analyzing the resulting diluted mixture. Severe wear in an oil wetted apparatus may be detected by directly analyzing spectrometrically a sample of the oil and comparing the results of such analysis with the results obtained according to the acid dissolution method described above.