ASTM D5863 Nickel, Vanadium, Iron, and Sodium in Crude Oils and Residual Fuels
ASTM D5863 Standard Test Methods for Determination of Nickel, Vanadium, Iron, and Sodium in Crude Oils and Residual Fuels by Flame Atomic Absorption Spectrometry
TEST METHOD B - FLAME ATOMIC ABSORPTION WITH AN ORGANIC SOLVENT TEST SOLUTION
14. Apparatus
14.1 Refer to Section 7.1.
14.2 Test Solution Containers - Glass or plastic vials or bottles, with screw caps and a capacity of between 50 to 100 mL. Glass bottles of 100-mL capacity are satisfactory.
15. Reagents
15.1 Dilution Solvent - Mixed xylenes, o-xylene, tetralin and mixed paraffin-aromatic solvents are satisfactory (Warning - Combustible. Vapor harmful.). Solvent purity can affect analytical accuracy when the sample contains low concentrations (typically, a few mg/kg) of the analytes.
15.2 Mineral Oil - A high-purity oil such as U.S.P. white oil.
15.3 Organometallic Standards - Pre-prepared multi-element concentrates containing 100 mg/kg concentrations of each element are satisfactory.
16. Preparation of Standards and Test Solutions
16.1 Test Solution - Weigh a portion of well-mixed sample into a container and add solvent to achieve a sample concentration of either 5 % (m/m) or 20 % (m/m). Mix well. If the concentration of V, Ni, or Na in the sample exceeds 20 mg/kg, the analysis for that element is performed on a test solution containing 5 % (m/m) sample. For concentrations less than 20 mg/kg, the analysis for that element is performed on a test solution that contains 20 % (m/m) sample.
16.2 Standards - If the test solution contains 5 % (m/m) sample, then the corresponding working standards and check standard must contain 5 % (m/m) oil. Similarly, if the test solution contains 20 % (m/m) sample, the standards must contain 20 % (m/m) oil. A consistent dilution factor is necessary so that all aspirated samples and standards will have the same viscosity. This is essential to obtain consistent uptake rates.
16.2.1 Working Standards - Prepare a blank (from mineral oil) and three additional working standards (from the organo-metallic standards) that cover the ranges of concentration specified in Table 2.
16.2.2 Check Standard - Using the organometallic standards, mineral oil, and dilution solvent, prepare a check standard to contain analyte concentrations approximately the same as expected in the test solutions.
17. Preparation of Apparatus
17.1 Refer to Section 11.
18. Calibration and Analysis
18.1 Refer to Section 12.
19. Quality Assurance/Quality Control (QA/QC)
19.1 Refer to Section 13.
