Automating the Workflow for the Analysis of Soils by ICP-OES

Importance of the Topic

The analysis of soil samples by ICP-OES is crucial in environmental monitoring pollution assessment and regulatory compliance High matrix soils present challenges in dilution calibration and throughput Automation of dilution and sample introduction reduces errors accelerates analysis and improves data quality

Objectives and Study Overview

This study evaluates the integration of an Advanced Dilution System ADS2 and an Advanced Valve System AVS7 with an Agilent 5800 Vertical Dual View VDV ICP-OES for automated analysis of soils following EPA 6010D The goal is to demonstrate how workflow automation handles high sample loads maintains accuracy and preserves throughput

Methodology and Instrumentation

Soil samples were digested by microwave assisted HNO3 according to EPA 3051A Calibration standards and sample dilutions were prepared inline using the ADS2 with dilution factors up to 400 Reactive and prescriptive autodilutions were applied based on QC limits Sample introduction was managed by AVS7 switching valve and an SPS4 autosampler Data acquisition used Agilent ICP Expert Pro software

Instrumentation Used

• Agilent 5800 VDV ICP-OES with VistaChip III detector
• Advanced Valve System AVS7 for rapid sample switching
• Advanced Dilution System ADS2 dual syringe autodiluter
• SPS4 autosampler
• CEM microwave digestion system

Main Results and Discussion

Detection limits in solution corresponded to sample MDLs below 1 mgkg for most elements Calibration curves achieved correlation coefficients above 09998 SRM recoveries fell within certified ranges across 33 elements Spike recoveries for trace analytes met EPA acceptance criteria of plusminus 25 Autodilution proved precise with CCV solutions remaining within plusminus 10 and RSDs below 2 over seven hours Sample to sample times increased by only two seconds when undiluted automation was active

Benefits and Practical Applications of the Method

• Automated creation of multilevel calibrations from single stocks spanning wide concentration ranges
• Prescriptive autodilution reduces manual preparation time and potential contamination
• Reactive autodilution ensures in range measurements and minimizes reanalysis
• Result summary feature consolidates data from multiple dilutions without analyst intervention

Future Trends and Potential Applications

Further integration of automation and remote operation can extend to field portable systems Machine learning based QC decision making and real time data correction may enhance throughput and robustness Advances in microfluidics could lead to more compact autodilution modules Green chemistry approaches may reduce reagent consumption and waste

Conclusion

The combination of the Agilent 5800 VDV ICP-OES with ADS2 and AVS7 delivers accurate multi element soil analysis with minimal manual intervention High throughput low detection limits and robust quality controls make this workflow well suited for environmental laboratories complying with EPA standards

References

1. Agilent Technologies Advanced Dilution System ADS2 Technical Overview publication 59947211EN
2. US EPA Method 6010D Inductively Coupled Plasma Atomic Emission Spectrometry Revision 5 July 2018
3. US EPA Method 3051A Microwave Assisted Acid Digestion of Sediments Sludges Soils and Oils Revision 1 February 2007
4. Riles P Analysis of Waste Samples According to US EPA Method 6010D Agilent publication 59942027EN