Multi-elemental determination of gasoline using Agilent 5100 ICP-OES with oxygen injection and a temperature controlled spray chamber

Significance of the topic

Determination of trace metals in gasoline is crucial due to potential environmental impact and engine component damage such as catalyst poisoning and sensor fouling. Reliable multi-element analysis at sub-ppm levels supports quality control and regulatory compliance in fuel production.

Study objectives and overview

This application note demonstrates the use of the Agilent 5100 SVDV ICP-OES with oxygen injection and a temperature controlled spray chamber for simultaneous determination of 21 elements in gasoline. The aim is to achieve high sensitivity, stable plasma operation and robust long term performance when analyzing volatile organic matrices.

Methodology and instrumentation

The study employed the method of standard additions to compensate for matrix effects in a 10% oil–in–solvent dilution of gasoline. Key features of the setup included:

• Agilent 5100 Synchronous Vertical Dual View ICP-OES operating at 27 MHz SSRF
• Radial view with a vertical organic torch (0.8 mm injector) and temperature controlled IsoMist spray chamber at –10 °C
• Oxygen injection into the auxiliary argon flow to minimize carbon deposition and improve plasma stability

An autosampler and glass concentric nebulizer completed the volatile organics introduction system.

Main results and discussion

Calibration showed excellent linearity (correlation coefficients > 0.999) across all analytes. Method detection limits were in the sub-ppm range for all 21 elements. FAST Automated Curve-fitting Technique (FACT) background correction further improved detection limits for phosphorus and lead. Spike recoveries at 0.5 and 1.0 ppm ranged between 98 and 108%. Only silicon was detected in the unspiked gasoline at around 0.0117 mg/kg. Long term stability testing over eight hours and 600 injections demonstrated < 3% RSD for all elements without recalibration.

Benefits and practical applications of the method

• Sub-ppm detection limits enable trace analysis of critical elements
• Stable plasma with minimal carbon fouling allows extended unattended runs
• Standard additions approach ensures accuracy in complex hydrocarbon matrices
• Versatile technique applicable to routine quality control in petrochemical laboratories

Future trends and potential applications

Anticipated developments include:

• Integration with online monitoring systems for continuous fuel quality assessment
• Expansion to biofuel blends and other volatile organic matrices
• Combination with separation techniques for element speciation
• Advances in spectral deconvolution algorithms to further reduce interferences

Conclusion

The Agilent 5100 SVDV ICP-OES with oxygen injection and cooled spray chamber offers a robust and sensitive platform for multi-element analysis in gasoline. The method delivers reliable quantification at trace levels, excellent precision over long runs, and straightforward operation for routine analytical workflows.

Reference

• Real-time spectral correction of complex samples using FACT spectral deconvolution software, Agilent publication 5991-4854EN (2014)