Ultrafast agricultural soil analysis using the Thermo Scientific iCAP 7600 ICP-OES Radial

Importance of the Topic

Precision assessment of soil nutrient levels is fundamental to modern agriculture. Rapid, field-relevant analysis enables targeted fertilization, minimizes waste, and supports both economic efficiency and environmental stewardship.

Study Objectives and Overview

This application note demonstrates an ultrafast screening method for surface soil samples using the Thermo Scientific iCAP 7600 ICP-OES Radial. The primary goal was to achieve analysis times under 20 seconds per sample while maintaining acceptable precision for major, trace, and micronutrient elements.

Methodology

Soil samples were air-dried, sieved to remove debris, and ground to homogenize. Five grams of each sample were extracted with 20 mL of 1 M ammonium acetate (Mehlich 3) solution. After vigorous shaking, the mixture was left to react overnight, re-shaken, filtered, and diluted to 250 mL with deionized water. Extracts were analyzed directly without further dilution.

Used Instrumentation

• Thermo Scientific iCAP 7600 ICP-OES Radial with radial plasma view and integrated Sprint Valve sample introduction system
• Teledyne CETAC ASX-560 autosampler (optionally XLR-860 extended rack for higher throughput)
• Qtegra Intelligent Scientific Data Solution (ISDS) software using Sprint acquisition mode

Main Results and Discussion

Eleven elements (B, Ca, Cu, Fe, K, Mg, Mn, Na, P, S, Zn) were measured at optimized wavelengths. A representative soil extract was analyzed in 50 replicates (five extractions × ten replicates each) over 11 minutes 35 seconds, corresponding to 13.9 seconds per sample. Relative standard deviations across all elements were below 10%, demonstrating acceptable precision for screening purposes.

Benefits and Practical Applications

This workflow delivers high-speed analysis suitable for agronomy labs performing large sample batches. Key advantages include:

• Throughput exceeding 250 samples per hour
• Minimal sample preparation and reagent consumption
• Automated operation reduces labor demands
• Data quality sufficient for guiding variable-rate fertilization

Future Trends and Opportunities

Advances may include integration with in-field sampling devices, miniaturized spectrometers for on-site testing, expansion to additional analytes (e.g., heavy metals), and coupling with machine-learning tools for predictive soil mapping and dynamic fertilization algorithms.

Conclusion

The Thermo Scientific iCAP 7600 ICP-OES Radial achieves ultrafast soil nutrient screening with sub-20-second analysis times and precision suitable for high-throughput agronomic workflows. Its combination of high matrix tolerance, automated sample handling, and rapid acquisition positions it as a powerful tool for precision agriculture.

References

• Thermo Fisher Scientific. 2017. Application Note 43156: Ultrafast agricultural soil analysis using the Thermo Scientific iCAP 7600 ICP-OES Radial.