ASTM D3831 for Manganese in Gasoline By Atomic Absorption Spectroscopy
9. Procedure
9.1 Deliver 100 µL of bromine solution into a vial.
9.2 Add 1.0 mL of the gasoline sample. Mix well.
9.3 Add 9.0 mL of methyl isobutyl ketone. Mix well.
9.4 Aspirate the working standards and the sample into the flame and record the absorbances of each.
NOTE 3 - Measure absorbances of the working standards and the samples promptly as the sample absorbances may change with time.
10. Calculations
10.1 The direct concentration read out of the instrument is the preferred mode of quantification. Alternatively, plot the absorbance values that were obtained by aspirating the working standard solutions versus manganese concentration and draw the best straight line through the points. From the plot read the manganese concentration corresponding to the absorbance of the gasoline sample. Report the manganese content of the gasoline to the nearest 0.1 mg/L Mn.
11. Quality Control
11.1 Confirm the performance of the test procedure by analyzing a quality control (QC) sample that is stable and representative of the sample of interest.
11.2 When the quality control/quality assurance protocols are already established in the testing facility, these may be used to confirm the reliability of the test result.
11.3 When there is no quality control/quality assurance protocol established in the testing facility, Appendix X1 can be used to perform this function.
