WCPS: Improved Productivity for the Determination of Metals in Oil Samples using the Agilent 5110 Radial View (RV) ICP-OES with Advanced valve system

Significance of the Method

The rapid and accurate monitoring of metal content in lubricating and engine oils is essential for equipment health assessment and quality control of base oils and additive packages. The ASTM D5185-13 standard has become a benchmark for detecting wear and additive elements in used and new oils. Advanced instrumentation that enhances throughput and reduces operating costs while maintaining data quality can drive efficiency in industrial and research laboratories.

Objectives and Study Overview

This study evaluates the performance of the Agilent 5110 Radial View ICP-OES equipped with an Advanced Valve System AVS 6 and an SPS 4 sample preparation system for the determination of 22 metals in engine oil. Key aims include assessing method accuracy via spike recovery, establishing detection limits, measuring linear dynamic range, and demonstrating long term stability and argon consumption for high throughput analysis.

Methodology and Instrumentation

The analysis followed ASTM D5185-13 protocols. Sample introduction employed an SPS 4 autosampler and AVS 6 valve system to automate uptake, stabilization and washout steps. A radial view plasma with a plug and play torch and a solid state RF generator handled organic solvent matrices. Operating parameters included an RF power of 1.3 kW, plasma flow of 12 L/min, auxiliary flow of 1 L/min and nebulizer flow of 0.65 L/min. Calibration standards ranged from 0 to 100 ppm, with higher concentration standards for specific elements. All solutions were matrix matched in 10 weight percent oil in kerosene.

• ICP-OES Model: Agilent 5110 Radial View
• Sample Introduction: Agilent SPS 4 and AVS 6 Advanced Valve System
• Plasma Gas Conditions: RF power 1.3 kW, plasma flow 12 L/min, auxiliary flow 1 L/min, nebulizer flow 0.65 L/min
• Calibration Range: 0 to 100 ppm and extended ranges for selected elements
• Matrix: Base Mineral Oil 75 cSt in kerosene

Main Results and Discussion

Excellent linearity was observed for all elements, with correlation coefficients above 0.999. Calcium calibration up to 250 ppm exhibited an error below 3 percent at each level. Method detection limits ranged from low micrograms per kilogram for trace elements to sub milligram per kilogram levels for major elements. Spike recoveries for all 22 elements fell within plus or minus 10 percent of expected values. Long term stability over a six hour sequence of 1000 samples yielded relative standard deviations between 1.1 and 2.7 percent and concentration deviations under 10 percent. The sample throughput was 22 seconds per sample with AVS 6, consuming 7 liters of argon gas per run. Without the AVS 6, analysis time increased to 52 seconds per sample.

Benefits and Practical Applications

• High throughput analysis enabling over 150 samples per hour
• Reduced argon consumption translating into lower operating costs
• Robust performance with minimal signal drift and excellent repeatability
• Accurate monitoring of wear metals for predictive maintenance programs
• Quality assurance of base oils and additive evaluations in industrial laboratories

Future Trends and Opportunities

The integration of advanced valve systems and automated sample handling is expected to expand into other challenging matrices such as biodiesel and complex environmental samples. Further developments in ICP-OES plasma control and detector sensitivity may enable simultaneous extended dynamic range analysis with minimal method optimization. Coupling this approach with real time data processing and machine learning algorithms could enhance predictive maintenance strategies and quality control workflows.

Conclusion

The Agilent 5110 Radial View ICP-OES with SPS 4 and AVS 6 provides a powerful solution for rapid and reliable determination of metals in oil samples. It combines high throughput, low argon consumption, robust long term stability, and accurate quantification in line with ASTM D5185-13. This configuration facilitates efficient industrial and research laboratory operations for oil condition monitoring and quality assurance.

References

• ASTM D5185-13 Standard Test Method for Oil Analysis
• Drvodelic N and Kulikov E Agilent Application Note EWCPS17 P 368