ASTM D4768 for 2,6-Ditertiary-Butyl Para-Cresol and 2,6-Ditertiary-Butyl Phenol
ASTM D4768 Standard Test Method for Analysis of 2,6-Ditertiary-Butyl Para-Cresol and 2,6-Ditertiary-Butyl Phenol in Insulating Liquids by Gas Chromatography
3. Summary of Test Method
3.1 The test specimen is placed onto a column containing activated alumina and extracted to remove interfering substances. The inhibitors are then eluted from the column with suitable solvent and analyzed by gas chromatography. The inhibitor type and quantity are determined by comparison of each component with a working standard tested under similar conditions.
4. Significance and Use
4.1 In new electrical insulating oil, this test method provides a quantitative measure of the amounts of 2,6-ditertiary-butyl para-cresol and 2,6-ditertiary-butyl phenol that have been added to the oil. In a used oil, the test measures the amount of these inhibitors remaining in the oil. This test method is suitable for manufacturing control, specification acceptance, and service evaluation.
4.2 This test method is used to separate, identify, and quantify the inhibitors with minimal interference and matrix effects.
4.3 This test method has also been used successfully to determine the inhibitor concentrations in other insulating liquids such as esters and high-temperature hydrocarbons.
