ASTM D5708 Method for Nickel, Vanadium, and Iron in Crude Oils and Residual Fuels
ASTM D5708 Standard Test Methods for Determination of Nickel, Vanadium, and Iron in Crude Oils and Residual Fuels by Inductively Coupled Plasma (ICP) Atomic Emission Spectrometry
18. Calculations
18.1 For Test Method A, calculate the concentration of each analyte in the sample using the following equation:
analyte concentration, mg/kg = C x F
where:
C = concentration of the analyte in the specimen solution, mg/kg, and
F = dilution factor.

18.2 For Test Method B, calculate the concentration of each analyte in the sample using the following equation:
analyte concentration, mg/kg = (C x V x F)/W
where:
C = concentration of the analyte in the specimen solution (corrected for the concentration determined in the reagent blank), mg/L
V = volume of the specimen solution, mL,
F = dilution factor, and
W = sample mass, g.

19. Quality Control
19.1 Confirm the performance of the test procedure by analyzing a quality control (QC) sample (9.5 for Test Method A or 14.5 for Test Method B).
19.1.1 When QC/Quality Assurance (QA) protocols are already established in the testing facility, these may be used to confirm the reliability of the test result.

19.1.2 When there is no QC/QA protocol established in the testing facility, Appendix X1 can be used as the QC/QA system.