Determination of Elemental Impurities in Petroleum Distillates Using ICP-MS ~ASTM D8110-17~

Significance of the Topic

Petroleum distillates often contain trace metal impurities such as nickel, vanadium and iron, which can poison catalysts, degrade fuel quality and increase environmental emissions. Sensitive and reliable analysis of these elemental impurities supports quality control and regulatory compliance in the refining and petrochemical industries.

Goals and Overview of the Study

This study applies ASTM D8110-17 to quantify elemental impurities in light and middle petroleum distillates using the Shimadzu ICPMS-2050 with an organic solvent introduction system. Key objectives include validating a simple dilution-based sample preparation, determining detection limits, confirming accuracy via spike recoveries and certified reference materials, and assessing long-term analytical stability.

Methodology

• Sample Preparation: Diesel oil, petroleum benzine and petroleum ether were diluted 10× (w/w) with organic solvent (PremiSolv). Residual fuel oil reference material was diluted 1 000× for Ni, V and S analysis. Spike recovery tests employed known additions of oil-based multi-element standards.
• Calibration: Oil-based mixed and single-element standards (Li, Na, Mg, … Pb) were prepared at five concentration levels (STD1–STD5). A check standard matching STD2 concentration was used to monitor calibration drift.
• Interference Removal: Carbon-related polyatomic interferences (e.g. 12C12C+, 12C16O+) were suppressed via collision (He) and reaction (H₂) cell modes. Reaction mode (H2-B) reduced the background equivalent concentration for 24Mg to 0.8 ng/g.

Instrumentation

• ICPMS-2050 with organic solvent torch and cyclonic spray chamber.
• Platinum sampling cone, nickel skimmer cone and Ar–O₂ mixed gas to prevent carbon deposition.
• Solvent-resistant peristaltic pump tubing enabling inline addition of internal standards (Be, Sc, Y, In, Bi).

Main Results and Discussion

• Detection Limits: Instrument detection limits ranged from 0.004 ng/g (Mo) to 500 ng/g (S), depending on element and cell condition.
• Reference Material Analysis: Measured Ni (22 ppm), V (52 ppm) and S (3.45%) matched certified values within 2%.
• Spike Recoveries: Recoveries for 25 elements in diesel, benzine and ether ranged from 82% to 115%, demonstrating robust accuracy across matrices.
• Long-Term Stability: Over 6 h continuous analysis, check standard recoveries stayed within 90–110% and internal standard signals varied by less than 20%, meeting ASTM D8110-17 validation criteria.

Benefits and Practical Applications

• Eliminates complex acid digestion by employing simple organic solvent dilution, reducing risk of contamination or volatilization losses.
• Delivers high sensitivity and low detection limits for a broad range of metals in petroleum matrices.
• Demonstrates robust long-term performance suitable for routine quality control and regulatory testing.

Future Trends and Potential Applications

Advancements in solvent-tolerant interfaces and collision/reaction cell chemistries will further lower detection limits and increase throughput. Coupling with automated sample handling and data processing could enable real-time monitoring of refinery streams, additive evaluation in lubricants and direct analysis of environmental emissions.

Conclusion

The ICPMS-2050 with organic solvent introduction provides a validated, sensitive and stable method for quantifying trace elemental impurities in petroleum distillates according to ASTM D8110-17. Its simplified sample preparation, accurate calibration and long-term robustness make it a powerful tool for refining quality control, environmental monitoring and petrochemical analysis.

References

1. ASTM D7111-16 Standard Test Method for Determination of Trace Elements in Middle Distillate Fuels by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES)
2. ASTM D8110-17 Standard Test Method for Elemental Analysis of Distillate Products by Inductively Coupled Plasma Mass Spectrometry (ICP-MS)