Determination of Trace Levels of Fatty Acid Methyl Esters in Aviation Fuel by GC × GC–FID and Comparison with the Reference GC–MS Method

Due to the negative impact of the presence of fatty acid methyl esters in kerosene for the aviation industry, in this work a comprehensive two-dimensional gas chromatography method with flame ionization detector for the determination of trace levels of fatty acid methyl esters in kerosene was developed. It is based on the use of a first dimension polar column and a second dimension non-polar column. Identification of fatty acid methyl esters is based on retention times and the external standard calibration is used for quantitation. Results were compared with those obtained from the GC–MS reference method; good recoveries, close to 100 %, and limit of detection in a range from 3 to 6 μg kg⁻¹ were found without requiring a specific detector.

     

Quantitation method of N,N ′‐disalicylidene‐1,2‐propanediamine by comprehensive two‐dimensional gas chromatography coupled to a nitrogen chemiluminescence detector

Metal deactivator additives (MDAs) have been used for over 60 years to prevent metal catalyzed reactions in petroleum products; a commonly used metal deactivator is N,N′‐disalicylidene‐1,2‐propanediamine. The quantitation of low MDA concentrations in fuels is challenging due to the complexity of the sample matrix. In this work, this difficulty was overcome using GC × GC hyphenated with a nitrogen chemiluminescence detector. The high resolution power of GC × GC avoided co‐elution between the MDA and other sample matrix compounds; while the enhanced sensitivity of GC × GC and the use of a nitrogen chemiluminescence detector supplied a high sensitivity and specificity for nitrogen compounds. For the analysis, the MDA additive was derivatized with the silylation agent N,O‐bis (trimethylsilyl)trifluoroacetamide at room temperature and its quantitation was based on an external calibration curve; good linear response was obtained in the 1.4–8.6 ppm range.