Petrochemical Analysis: Determination of Antioxidant Additives in Gasoline
HPLC method for quantification of antioxidant additives in gasoline and petroleum products.
Petrochemical Analysis: Determination of Antioxidant Additives in Gasoline Article ID: AN-004 Category: Application Notes Subcategory: Petrochemical Analysis Author: Manus AI Published Date: 2026-02-05 --- Introduction Gasoline is a complex mixture of hydrocarbons that is susceptible to oxidation during storage, leading to the formation of gums and deposits that can impair engine performance. To prevent this degradation, antioxidant additives are added to gasoline formulations. These additives, typically hindered phenols, inhibit the oxidation process and ensure fuel stability. Monitoring the concentration of these antioxidants is a critical quality control step in the petrochemical industry, ensuring that the fuel meets specifications and will remain stable over time. This application note describes a normal-phase High-Performance Liquid Chromatography (NP-HPLC) method for the determination of two common phenolic antioxidants, 2,6-di-tert-butylphenol (BHT) and 2,4-dimethyl-6-tert-butylphenol, in gasoline samples. This method is relevant for refineries and fuel testing laboratories in regions like Russia and South America, where fuel quality standards are strictly enforced. Experimental Conditions Normal-phase HPLC is preferred for this analysis because gasoline is a non-polar matrix. A direct injection of gasoline onto a reversed-phase column would cause the non-polar gasoline components to be strongly retained, fouling the column. | Parameter | Condition | | :--- | :--- | | Instrument | Standard HPLC system with UV Detector | | Column | Silica, 5 µm, 4.6 x 250 mm | | Mobile Phase | n-Hexane : Isopropanol (99:1, v/v) | | Flow Rate | 1.5 mL/min | | Column Temperature | Ambient (25 °C) | | Detection Wavelength | 280 nm | | Injection Volume | 20 µL | Sample Preparation On