Interfering factors of distillate fuel oil oxidation safety tester method (accelerated method)
1 Oxidation is the main chemical process that leads to the formation of insolubles. Substances such as copper and chromium can catalyze the oxidation reaction, resulting in an increase in the amount of insolubles formed. Since the instruments used in this standard can also be used in the GB/T 12581 standard, this standard uses copper and steel coils as catalysts. If this standard and CB/T 12581 share a set of oxidation tubes, these metal residues must be thoroughly cleaned before use. At the same time, in order to prevent the presence of chromium ions, do not clean all glass instruments and oxidation tubes with silicate acid.
2 If the reagents with low purity are used in the triple mixture, the amount of adhesive insoluble matter will increase. Therefore, analytically pure or higher-purity reagents must be used when preparing the triple mixture.
3 The exposure of the sample to ultraviolet light will increase the amount of total insoluble matter, so the sample used in the test must avoid ultraviolet light (sunlight or fluorescence). The entire operation process of sample sampling, measurement, filtration and weighing should avoid direct sunlight. Preservation of the sample before oxygenation, oxygenation operation, and cooling after oxygenation should be carried out in the dark.
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