ASTM International

Standard Test Method for Measurement of Cellular Adenosine Triphosphate in Fuel, Fuel/Water Mixtures, and Fuel-Associated Water with Sample Concentration by Filtration
 N D7687

Annotation

This test method covers a protocol for capturing, extracting and quantifying the cellular adenosine triphosphate (cellular-ATP) content associated with microorganisms found in fuels, fuel/water mixtures and fuel-associated water.

The ATP is measured using a bioluminescence enzyme assay, whereby light is generated in amounts proportional to the concentration of cellular-ATP in the samples. The light is produced and measured quantitatively as relative light units (RLU) which are converted by comparison with an ATP standard, computation to pg ATP/mL and optional further transformation to Log10[pg ATP/mL].

This test method is equally suitable for use as a laboratory or portable method.

This test method is limited to fuels with a nominal viscosity < 75cSt at test temperature.

This test method detectsATP concentrations in the range of 5.0 pg ATP/mL (0.699 log10[pg ATP/mL]) to 100 000 pg ATP/mL (5.000 log10[pg ATP/mL]) for 20 mL samples of fuel or fuel/water mixtures, and 20 pg ATP/mL (1.301 log10[pg ATP/mL]) to 400 000 pg ATP/mL (5.602 log10[pg ATP/mL]) for 5 mL samples of fuel-associated water.

NOTE 1—These ranges were calculated with the formula for calculating sample ATP in pg/mL provided in 12.1 based on the minimum recommended RLU for a 1 ng ATP/mL standard when using the reagents specified in Section 7 and the luminometer specified in 6.4 and corrected with a reagent-method blank as determined in Appendix X5.

Providing interferences can be overcome, bioluminescence is a reliable and proven method for qualifying and quantifying ATP. This test method does not differentiate between ATP from different sources, for example: from different types of microorganisms, such as bacteria and fungi.