A high-temperature sensor analyzer: Determination of difficult volatile organic impurities in solvents

It was shown that an automated analyzer with solid-electrolyte sensor cells can be used to determine difficult volatile organic impurities (technical oils, gasoline, and kerosene) in organic solvents (alcohols, acetone, and turpentine) by their two-stage oxidation with atmospheric oxygen at 100 °C (evaporation of a light fraction) and at a temperature of 900 °C and higher (burning impurities). Optimum conditions are found for the rapid determination of trace amounts of MS-20 oil in washing solvents (ethanol, benzene): time of determination, 5 min/sample; aliquot portion, 10 μL; linearity range of the calibration graph, from 20 to 100 mg/L of organic impurity; detection limit, 2.5 mg/L; RSD ≥ 8%. The results of determining the concentrations of gasolines of different grades and other organic mixtures for identifying substance grades are discussed. The novelty and advantages of the developed method consist in the rapid and quantitative determination of the octane number and other parameters of hydrocarbon fuels without preliminary sample preparation and also in the possibility of analyzing liquid samples of any other origin without resorting to the chemical methods of analysis. The ecological safety of the method is also important.