ASTM D1840 Test Method for Naphthalene Hydrocarbons in Aviation Turbine Fuels
ASTM D1840 Standard Test Method for Naphthalene Hydrocarbons in Aviation Turbine Fuels by Ultraviolet Spectrophotometry
12. Calculations
12.1 Calculate the mass percentage of naphthalenes in the sample as follows:
Naphthalenes, mass % = (AK/33.7W) x 100
where:
A = corrected absorbance (observed absorbance minus cell correction) of the dilution measured,
For Procedure A in Section 10 using serial dilutions,
K = equivalent volume of solvent, in liters, if the dilution had been made in a single step. For the first dilution K = 0.025, for the second dilution K = 0.25, for the third dilution K = 2.5. For the suggested alternative third dilution K = 0.625,
For Procedure B in Section 11 using 100-mL dilution,
K = 0.10,
W = grams of sample used, and
33.7 = the average absorptivity of C10 to C13 naphthalenes in litres per gram-centimeter.
12.2 Calculate the volume percentage of naphthalenes as follows:
Naphthalenes, volume % = M x (B/C)
where:
M = percentage of naphthalenes by mass,
B = relative density of the total fuel (15°C/15°C), and
C = relative density of the naphthalenes (15°C/15°C) = 1.00.
