Eliminate the Dilution Step from ICP-MS Sample Prep with the Agilent High Matrix Introduction System

Importance of the topic

Direct measurement of environmental samples with high dissolved solids by ICP-MS is crucial to speed up analysis, reduce preparation errors, lower reagent consumption and cut overall costs while maintaining compliance with regulatory methods.

Objectives and overview of the study

This study aimed to assess the performance of the Agilent High Matrix Introduction accessory on the 7500ce ICP-MS for direct analysis of soil digestates and Toxicity Characteristic Leaching Procedure (TCLP) samples without conventional dilution. Analysts at TestAmerica compared method detection limits, workflow efficiency and operational costs against the standard 1:10 dilution approach.

Methodology and instrumentation used

Sample preparation followed USEPA Method 3050B for soils (10% HCl hot‐plate digestion) and Method 3010A for liquids (5% HCl). The HMI system permitted direct introduction of solutions with total dissolved solids up to 1%. Standards and blanks were prepared in 5% HNO3/5% HCl to match sample acidity. The Agilent 7500ce ICP-MS was operated in an ultra‐robust mode, eliminating the need for platinum cones and minimizing matrix‐related interferences.

• Instrument: Agilent 7500ce ICP-MS with High Matrix Introduction accessory
• Sample types: Soil digestates and TCLP leachates
• Acid matrix for standards and blanks: 5% HNO3/5% HCl

Main results and discussion

Undiluted samples introduced via HMI showed improved method detection limits for most elements compared to 1:10 dilutions. Key observations:

• Significant MDL improvements for elements such as As, Ba, Cr, Fe and others, often by a factor of two or more
• Consistent removal of matrix suppression effects without increased cone wear
• Streamlined workflow by eliminating the dilution step, reducing contamination risk and human error

Benefits and practical applications of the method

Implementation of HMI in routine environmental analysis delivers:

• Increased sample throughput and shorter turnaround times
• Reduced reagent usage and waste generation
• Enhanced detection capabilities via lower MDLs
• Cost efficiencies through fewer consumables and lower disposal volumes

Future trends and applications

The HMI approach is expected to expand into diverse fields such as mining, industrial QA/QC and water quality monitoring. Anticipated advancements include:

• Enhanced collision/reaction cell integration for additional interference removal
• Automation improvements for high-throughput screening
• Adaptation to more challenging matrices like seawater and petroleum residues

Conclusion

The Agilent High Matrix Introduction system paired with the 7500ce ICP-MS enables direct analysis of high-matrix samples, delivering improved detection limits, streamlined workflows and notable cost savings. This innovation supports accurate and efficient environmental testing in line with USEPA guidelines.

References

• Agilent Technologies Inc. Eliminate the Dilution Step from ICP-MS Sample Prep with the Agilent High Matrix Introduction System. Application Note 5989-8573EN, May 21, 2008.