Content Analysis of Toxic Elements in Soil by ICPE-9800 Series

Importance of the Topic

Assessing toxic elements in soil is essential for safeguarding water quality and human health. Contaminated soil can leach harmful metals into drinking water sources and pose direct ingestion risks, particularly to children.

Objectives and Study Overview

This study evaluates the performance of the Shimadzu ICPE-9800 series inductively coupled plasma atomic emission spectrometer for the quantification of seven toxic elements in soil. Both a standard elution protocol and a total digestion approach are compared against certified reference materials JSAC0402 and JSAC0403.

Methodology

Two sample preparation methods were implemented:

• Acid elution following Ministry of the Environment Notification No. 19: 6 g soil extracted with 200 mL of 1 M HCl, filtered, and spiked with ytterbium (Yb) and indium (In) as internal standards.
• Total digestion via microwave-assisted sample preparation: 0.2 g soil treated with nitric and hydrofluoric acids, heated to near dryness, redissolved in dilute acids, and spiked with Yb and In; final volume adjusted to 20 mL.

Applied Instrumentation

The ICPE-9800 series offers high-throughput multi-element analysis with reduced running costs:

• Mini torch plasma with gas flows of 10 L/min (plasma), 0.6 L/min (auxiliary), and 0.7 L/min (carrier)
• RF power: 1.2 kW; axial observation mode; 2.5 min per sample (including rinse)
• CCD detector for simultaneous wavelength acquisition; Eco mode and vacuum spectrometer design to minimize gas and power usage

Main Results and Discussion

Spectral overlap from matrix elements (e.g., Fe interference at Cd 214.438 nm) was effectively corrected using software interference element correction, improving accuracy. Detection limits achieved were below one-tenth of regulatory reference values for all target elements. Quantified concentrations closely matched certified values for both JSAC0402 and JSAC0403 across preparation methods.

Benefits and Practical Applications

• High sensitivity and precision enable trace-level quantification compliant with soil contamination standards.
• Eco-mode operation and minimized gas consumption reduce operational costs.
• Capability for rapid analysis supports large-scale environmental monitoring and regulatory compliance.

Future Trends and Opportunities

Further enhancements in torch design and detector sensitivity could lower detection limits. Automation of sample preparation and integration with data-analysis algorithms will streamline workflows. Applying this technology to a broader range of environmental and industrial matrices presents ongoing opportunities.

Conclusion

The Shimadzu ICPE-9800 series ICP-AES system provides rapid, accurate, and cost-effective measurement of toxic elements in soil, meeting stringent regulatory requirements and supporting environmental risk assessment.

Reference

1. Ministry of the Environment Ordinance No. 29, Soil Contamination Countermeasures Law Enforcement Regulations, 2002.
2. Ministry of the Environment Notification No. 19, Determination of Measurement Methods According to Soil Content Investigation, 2003.
3. JIS K0102-2013 Testing Method for Industrial Wastewater.
4. US EPA SW-846 Method 3052 Microwave Assisted Acid Digestion of Siliceous and Organically Based Matrices.