GCC: Best practices for the analyses of complex samples by ICP-OES and ICP-MS: Streamline workflow for accurate results

Importance of the Topic

ICP-OES and ICP-MS are core techniques for multi-element and trace-level elemental analysis across petrochemical, environmental, and quality-control laboratories. Complex sample matrices such as crude oil, wastewater, brines, and sludges pose significant challenges to accuracy, sensitivity, and throughput. Streamlining the analytical workflow is essential to deliver reliable results while meeting stringent regulatory requirements and reducing downtime.

Study Objectives and Overview

This work by Mike Mourgas (Thermo Fisher Scientific) identifies common obstacles in the analysis of complex matrices by ICP-OES and ICP-MS and presents best practices, instrumental innovations, and method optimizations to enhance data quality, speed, and robustness. The focus spans sample preparation, instrumentation, software tools, and troubleshooting strategies aimed at environmental, petrochemical, and industrial laboratories.

Methodology and Instrumentation

Key aspects of the streamlined workflow include:

• Sample and Standard Preparation
  • Use of high-purity reagents, plastics (PTFE, PFA, PP), Class A glassware where necessary, and ultrapure water to minimize contamination.
  • Implementation of hot-plate, hot-block, or microwave digestion depending on sample type, balancing throughput with digestion quality.
  • Automated standard and sample dilution using autosampler autodilution systems to reduce manual errors and preparation time.
• Sample Introduction Components
  • Selection of nebulizer, spray chamber, injector, and torch based on matrix (e.g., concentric glass for low-TDS, PFA or high-solids kits for brines, ceramic D-torch for HF or oil samples).
  • Use of sheath-gas adaptors to enhance plasma robustness when analyzing high-solid or high-salt matrices.
• Instrument Innovations
  • Thermo Scientific iCAP PRO Series ICP-OES featuring compact footprint, enhanced optics (CID detector, eUV mode), and Purged Optical Path for high matrix tolerance.
  • Thermo Scientific iCAP RQ and TQ ICP-MS systems offering quick-connect sample introduction, interchangeable cones, QCell collision/reaction technology (He KED + LMCO) for comprehensive interference removal, and advanced skimmer-cone inserts for robustness.
• Software and Method Development
  • Qtegra ISDS software integrates instrument control, autotuning, LabBook creation, 21 CFR 11 compliance tools, and streamlined data processing.
  • Auto-Tune feature automatically optimizes plasma power, nebulizer gas flows, and viewing parameters based on signal-to-background criteria.

Main Results and Discussion

Application of these best practices and technologies led to:

• Significant reduction in sample preparation and digestion times—from hours to minutes with microwave systems.
• Improved stability and reduced drift when analyzing high-TDS and organic-rich samples by selecting appropriate torches, injectors, and sheath gas configurations.
• Lower detection limits and expanded linear ranges through optimized plasma conditions and autodilution, enhancing quantitation from major to trace levels in a single run.
• Robust interference correction via background point placement, interelement correction factors, and QCell collision/reaction cell modes assuring accurate results in the presence of spectral overlaps and easily ionized element effects.
• Enhanced workflow efficiency and reproducibility through autosampler automation and integrated software controls, reducing operator variability and manual intervention.

Benefits and Practical Applications

The optimized workflow supports:

• High-throughput QA/QC in refining, lubricant analysis, and in-service chemical monitoring with rapid turnaround to sustain continuous plant operations.
• Comprehensive environmental monitoring of wastewater, solid wastes, and regulatory compliance testing under EPA, ASTM, and drinking water standards with reliable low detection limits.
• Streamlined laboratory operations with reduced instrument maintenance, fewer sample reruns, and minimized contamination risk, resulting in cost and time savings.

Future Trends and Potential Applications

Emerging directions include:

• Broader adoption of triple-quadrupole ICP-MS for advanced speciation and even greater interference control.
• Integration of AI-driven diagnostics and remote monitoring to predict maintenance needs and optimize performance in real time.
• Further miniaturization and green chemistry approaches to reduce reagent consumption and lab footprint.
• Seamless data exchange with LIMS, blockchain-enabled data security, and enhanced digital compliance tools.

Conclusion

By combining rigorous sample preparation, tailored sample introduction, innovative instrumentation, and intelligent software, laboratories can achieve accurate, reproducible, and efficient elemental analyses of the most challenging sample matrices. Implementing these best practices not only enhances data quality and regulatory compliance but also streamlines operations and reduces total cost of ownership.

References

• Mourgas M. Best practices for the analyses of complex samples by ICP-OES and ICP-MS: Streamline workflow for accurate results. Thermo Fisher Scientific; 2022.