Analysis of Environmental Samples Following US EPA Guidelines Utilizing a New Simultaneous CCD Detector ICP-OES System

Importance of the Topic

Environmental monitoring of trace elements in water and soil is vital to assess contamination, guide cleanup actions and support regulatory enforcement. Complying with US EPA Contract Laboratory Program (CLP) Method ILM05.3 ensures data quality for emergency response, litigation and environmental remediation efforts. Advances in simultaneous CCD-based ICP-OES instrumentation offer faster turnaround, extended dynamic range and robust quality control to meet stringent EPA requirements.

Objectives and Study Overview

This study evaluates a new simultaneous-CCD-detector ICP-OES system (Varian 730-ES) with a four-port switching valve (SVS1) to perform US EPA ILM05.3 compliant analysis of water samples. The goals were to demonstrate achievement of required method detection limits for 22 target elements, to verify accuracy using standard reference materials and spikes, and to show improved sample throughput and reduced operating costs.

Methodology and Used Instrumentation

Sample matrix was acidified water with 1% HNO₃ and 5% HCl. Calibration and QC employed NIST SRM 1643e and EPA CLP kits. Continuous integration technology automatically adjusted read times for optimum signal-to-noise. Quality checks included continuing calibration verification, interference checks and sample spikes.

• ICP-OES system: Varian 730-ES simultaneous CCD detector with I-MAP optics (167–785 nm coverage)
• Switching Valve: Four-port SVS1 for rapid uptake and rinse
• Autosampler: SPS-3 or Cetac ASX-520
• Plasma Conditions: 1.4 kW RF, 15 L/min plasma gas, axial torch
• Background Correction: One or two-point off-peak

Results and Discussion

The system met or exceeded ILM05.3 requirements for all elements, achieving method detection limits well below regulatory concentration reporting levels. Recoveries for NIST SRM 1643e averaged 98–106%. Spike recoveries in tap water ranged from 98–112%. Precision over multiple hours showed RSD <1% for key analytes. Simultaneous detection eliminated the need for sequential wavelength scans.

Benefits and Practical Applications

By combining strong and weak spectral lines and measuring multiple lines per element, the method delivers reliable confirmation of results. The rapid sample uptake and instant rinse protocol reduced carry-over and increased throughput by over 30% versus conventional single-line ICP-OES. Lower argon and torch gas consumption reduce operating expenses.

Future Trends and Potential Applications

Integration of Peltier-cooled CCDs with off-chip electronics and adaptive integration technology paves the way for real-time monitoring of environmental discharges and higher matrix tolerance. Future developments may include automated speciation analysis, coupling with laser ablation for solid samples, and cloud-based data management for large-scale monitoring networks.

Conclusion

The Varian 730-ES simultaneous CCD ICP-OES with SVS1 meets US EPA ILM05.3 requirements while delivering faster, more cost-effective environmental trace element analysis. It ensures regulatory compliance, high data quality and increased laboratory productivity.

Reference

US EPA. ILM05.3, EPA Publication 540-F-04-001; 2004.