Agilent 720/725 ICP-OES

Significance of the Topic

The determination of elemental composition in diverse sample matrices is critical for environmental monitoring, food safety, industrial quality control, and research. Simultaneous, high-throughput, and interference-free analysis of major, minor, and trace elements drives greater productivity and confidence in analytical results. Advanced ICP-OES platforms that combine robust plasma generation, minimal maintenance, and efficient resource consumption are indispensable for modern laboratories facing stringent regulatory standards and complex sample challenges.

Objectives and Overview of the Article

This application note presents the key features, performance enhancements, and application scope of the Agilent 720 and 725 ICP-OES systems. It aims to demonstrate:

• How next-generation detector and optical designs improve sensitivity, dynamic range, and simultaneous measurement capability.
• The differences between axially-viewed (720) and radially-viewed (725) configurations for various sample types.
• Software innovations and accessories that streamline method development, interference correction, and automated workflows.
• Practical benefits, cost savings, and real-world application examples across environmental, industrial, petrochemical, food, agricultural, and mining analyses.

Methodology and Instrumentation

The Agilent 720/725 ICP-OES systems employ a hermetically sealed VistaChip II CCD detector optimized for an echelle polychromator. Key methodological elements include:

• Adaptive Integration Technology (AIT) for real-time adjustment of integration times per wavelength, ensuring optimum signal-to-noise ratios across concentration ranges.
• Image Mapping Technology (I-MAP) to match the two-dimensional optical image directly to the detector pixel array, achieving full wavelength coverage (167–785 nm) without multiple detectors or slits.
• Custom Cooled Cone Interface (CCI) on the 720 system to remove cool plasma tail emissions, extending linear dynamic range and reducing matrix interferences in axial view.
• Choice of axial (720) or radial (725) plasma viewing orientation to optimize sensitivity or matrix tolerance depending on the application.
• ICP Expert II software features: Fitted Background Correction (FBC), Fast Automated Curve-fitting Technique (FACT), MultiCal for dynamic range extension, Smart Rinse, AutoMax optimization, and Time Resolved Spectroscopy (TRS) for speciation.

Main Results and Discussion

Performance metrics and findings highlight:

• True simultaneous, one-shot measurement of all elements and internal standards across ppb to percent levels, maximizing throughput.
• An optical resolution <8 pm and pixel resolution of 3 pm that resolve closely spaced lines (e.g., Cu 213.598 nm vs. P 213.618 nm).
• Trace detection limits in axial view (720) suitable for environmental, food, and agricultural samples; robust matrix tolerance in radial view (725) for petrochemical, mining, and high dissolved solids analyses.
• Dynamic range extension over seven orders of magnitude by combining multiple emission lines with differing sensitivities using MultiCal.
• High stability over eight-hour sequences with relative standard deviations <1% across major, minor, and trace elements without internal standardization.
• Argon consumption reduced by 20–40% compared to competing low-flow systems, due to a sealed detector requiring no purge, compact optics, and efficient RF plasma sustaining at lower gas flows.

Benefits and Practical Applications

The combined hardware and software innovations deliver tangible laboratory advantages:

• Reliable results with extended dynamic range and minimized spectral interferences by FBC and FACT, reducing method development time.
• Enhanced productivity through one-step measurement, rapid warm-up, automated optimization, and reduced carryover via Smart Rinse and SVS 2 switching valves.
• Cost savings from lower argon use, minimal maintenance requirements, and elimination of shear gas or dual-view complexity.
• Versatility across applications: environmental waters, soils, sediments; food and agricultural matrices; petrochemical solvents; industrial chemicals; mining ores; biodiesel and fuel additives; pharmaceuticals; wear metals in oils; precious metals analysis.

Future Trends and Opportunities

Emerging prospects for ICP-OES and allied techniques include:

• Integration with chromatographic (HPLC) or laser ablation sample introduction for advanced speciation and spatially resolved analysis.
• Enhanced data analytics and machine-learning algorithms for predictive maintenance, real-time interference correction, and method optimization.
• Integration of triple-quadrupole ICP-MS and MP-AES platforms for complementary elemental coverage, improved detection limits, and air-based plasma operation.
• Development of even more inert and high-throughput sample introduction systems to accommodate challenging matrices and ultra-low detection requirements.

Conclusion

The Agilent 720 and 725 ICP-OES systems set a new benchmark in simultaneous, high-performance optical emission spectrometry. By combining a sealed high-resolution CCD detector, optimized echelle optics, and advanced software, these platforms achieve unparalleled speed, sensitivity, robustness, and cost efficiency. Laboratories across environmental, industrial, petrochemical, agricultural, and mining sectors can confidently meet current and future analytical demands with improved productivity and data quality.

Instrumentation Used

• Agilent 720 ICP-OES (axial view) with Cooled Cone Interface (CCI)
• Agilent 725 ICP-OES (radial view)
• VistaChip II hermetically sealed CCD detector
• Echelle polychromator with CaF₂ prism cross-disperser
• Agilent ICP Expert II software
• Accessories: MSIS hydride system, SVS 2 switching valve, SPS 3 autosampler, OneNeb nebulizer, sheath gas torch