Standard test method for the determination of corrosion inhibitor additive containing di-linoleic acid in aviation turbine fuel using liquid-liquid extraction and colorimetry

1. This test method describes the procedure used to quantify corrosion inhibitor (CI) additive containing di-linoleic acid (sold commercially as DCI-4A) in CGSB-3.24 aviation turbine fuel (ATF) military grade F-34 sample using liquid-liquid extraction and color measurements.The linear dynamic range for this test method is between 3800 ppm and 21900 ppm DCI-4A.

2. This test method is also valid for CGSB-3.24, military grade F-44 ATF and CGSB-3.23, Grade Jet A-1 ATF, if di-linoleic acid CI additive is present.

3. In this method, a calibration curve is generated with standard solutions.Each standard solution is prepared with the same batch of CI additive used to additize the ATF sample.This is strongly recommended to improve the accuracy and precision of the test method.

    

   NOTE – This test method could be used to measure the CI additive containing di-linoleic acid in ATF samples even when standard solutions are prepared with a different batch of CI additive.  The calibration curve would have to be developed using any batch available.  Consequently, the color measurements could vary from the actual additive concentration because the di-linoleic acid content in neat additive varies between batches.  For example, the concentration of di-linoleic acid in neat DCI-4A additive is known to vary between 41% and 65%, with an average of 60%.

The testing and evaluation of a product against this method may require the use of materials and/or equipment that could be hazardous. This document does not purport to address all the safety aspects associated with its use.  Anyone using this method has the responsibility to consult the appropriate authorities to establish appropriate health and safety practices in conjunction with any applicable regulatory requirements prior to its use.