Covalent

Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES)

ICP‑OES quantifies multiple elements at very low concentrations, delivering fast, defensible results across complex samples.

What Is Inductively Coupled Plasma Optical Emission Spectroscopy?

Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), also called ICP Atomic Emission Spectroscopy (ICP-AES), measures the elemental composition of liquids or digested solid samples.

In ICP-OES, the atoms in an argon plasma are energized, causing them to emit light at element-specific wavelengths, each wavelength indicating a unique fingerprint.

ICP‑OES supports detection at the parts‑per‑billion (ppb) level. At Covalent, every method is built with rigorous control over sample prep, calibration, and spectral interpretation to ensure the data aligns with your decision-making needs.

Matrix Flexibility

Tolerates complex mixtures (biological, environmental, industrial) with robust digestion workflows that preserve accuracy.

Multi-Element Speed

Screens and quantifies dozens of elements in a single scan, with rapid throughput for both research and QA workflows.

High Sensitivity

Detects trace metals down to low parts-per-billion while maintaining linear response across wide concentration ranges.

Why Use ICP-OES?

ICP‑OES is an excellent choice for quick, economical trace elemental analysis, supporting projects that demand accurate multi‑element quantification without the complexity of higher‑sensitivity techniques.

It is ideally suited for trace metal detection, elemental impurity analysis, leaching studies, and stoichiometry determination, enabling reliable insights across research, manufacturing, and quality control workflows.

With excellent sensitivity, broad linear range, and robust matrix tolerance, ICP‑OES delivers fast, defensible results even for complex sample types, making it a practical and efficient tool for most elemental testing requirements.

Analytical Breadth

Handles trace to bulk concentrations (ppb to ppm), enabling impurity detection, stoichiometry validation, and compliance checks.

Application Versatility

Supports industries from semiconductors and energy storage to pharmaceuticals, food, and mining, with proven regulatory alignment.

Workflow Integration

Compatible with complementary methods (ICP‑MS, combustion, microwave digestion) to extend analytical coverage and confidence.

How ICP-OES Works

ICP-OES translates emitted light into quantitative elemental data. A liquid or digested solid sample is nebulized into a fine aerosol and then injected into a high-temperature argon plasma.

Inside the plasma, atoms emit photons as electrons return to the ground state. A detector captures these emissions, correlating wavelength intensity to elemental abundance.

Covalent’s platform is engineered to deliver accurate elemental profiles from even difficult sample matrices.

Equipment Used for ICP-OES

ThermoFisher Scientific iCAP-7400 Duo

  • Broad elemental coverage: Measures wavelengths from 166 to 847 nm for flexible multi-element analysis.
  • Stable detection: CID86 technology provides precise, repeatable measurements across wide concentration ranges.
  • Controlled optics: A temperature-stabilized polychromator maintains consistent resolution and accuracy.
  • Flexible workflows: Supports diverse sample matrices, autosampling, and microwave digestion.
  • High-throughput performance: Enables reliable trace metals analysis and rapid processing of large sample batches.
Specifications

Key Differentiators

ICP-OES is built for rapid, high-precision multi-element analysis. Our configuration supports both exploratory research and routine QA programs.

ICP‑OES detects trace and bulk elemental concentrations (ppb to ppm), enabling multi‑element profiling in complex mixtures and revealing impurities, leachates, and major constituents. Compatible with aqueous solutions, digested solids, alloys, polymers, oils, ceramics, biomaterials, pharmaceuticals, and minerals, ICP‑OES adapts to nearly any plasma‑ready matrix.

ICP-OES vs ICP-MS

Both techniques rely on plasma excitation but diverge in detection mode.

ParameterICP-OESICP-MS
DetectionOptical emission spectroscopyMass spectrometry
SensitivityModerate (ppb)High (ppt)
Isotopic AnalysisNot availableAvailable
Matrix ToleranceHighLower
ThroughputHigh (faster setup and analysis)Slower due to prep and interference control

When to Choose ICP-OES:

  • You need fast, multi-element screening.
  • Sample prep time is limited.
  • Matrix interference is a concern.
  • Isotopic or ultra-trace analysis is not required.

Get in touch with our experts to determine the best-fit technique for your matrix, detection thresholds, and reporting requirements.

Strengths

  • Detects elements at ppb concentrations.
  • Simultaneous multi-element scans.
  • Linear dynamic range across orders of magnitude.
  • Minimal sample mass required.
  • Compatible with aggressive digestion workflows.

Limitations

  • Requires samples in solution form.
  • Cannot resolve isotopes or molecular structures.
  • Surface and depth profiling are not supported.
  • Susceptible to matrix effects if not calibrated correctly.

Covalent addresses these challenges through matrix-matched standards, validated digestion workflows, and QA-verified calibration.

Example Outputs

The example below highlights how ICP‑OES delivers precise, repeatable results when quantifying Platinum Group Metals (PGMs) such as Au, Pd, Pt, Rh, and Ru. These elements are critical in advanced technologies and manufacturing, and accurate measurement is essential to ensure quality and performance.

  • Excellent agreement between replicate measurements across three aliquots.
  • High precision, with results closely matching the expected reference values.
  • Reliable quantification of precious metals, even at elevated concentrations.
These results highlight the consistent precision and accuracy of the ThermoFisher iCAP‑7400 ICP‑OES system, giving researchers and engineers confidence in sensitive elemental measurements.

Sample Requirements

ICP-OES can analyze liquids and aqueous extracts, as well as solid materials that can be converted into plasma-compatible solutions, including metals, ceramics, polymers, composites, complex bulk mixtures, and residues.

  • Liquid samples and aqueous extracts can often be analyzed directly or after dilution.
  • Solid samples must be digested or dissolved before analysis.
  • Acid digestion, microwave digestion, or combustion may be required, depending on the sample composition.
  • Samples must be compatible with the plasma and sample introduction system.
  • Milligram-scale quantities are typically sufficient, although exact requirements depend on the material and analytical goals.

ICP-OES Applications by Industry

Semiconductor & Microelectronics

Monitor trace metals in wafers, resists, and components to protect device integrity.

Pharmaceutical / Biotech / Clinical Labs

Detect elemental impurities in APIs, excipients, and biologics for regulatory compliance.

Energy Storage & Power Generation

Analyze electrolytes, electrodes, and degradation products in batteries and fuel cells.

Environmental Monitoring & Compliance

Measure trace metals in water, soils, and effluents to meet safety standards.

Food / Agriculture / Nutrition Science

Profile nutrients and contaminants in consumables, fertilizers, and animal feeds.

Geology / Mining / Metallurgy

Characterize ores, validate alloys, and track elemental composition during extraction and refining.

Techniques That Complement ICP-OES

XRF
Non-destructive solid-state elemental analysis.
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Surface imaging, low-concentration elemental ID.
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Elemental + bonding environment, surface analysis.
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Halides and organic acids not detected by ICP-OES.
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Why Choose Covalent for Your ICP-OES Needs?

Covalent delivers rigorous, high-throughput ICP-OES analysis tailored to each sample’s chemistry and project goals. Our workflows combine microwave digestion, matrix-matched calibration, and controlled combustion with the speed and sensitivity of the iCAP 7400. By aligning reporting thresholds with your compliance, production, and development requirements, we provide accurate, actionable data that supports confident decisions.

Frequently Asked Questions

When should I use ICP-OES instead of ICP-MS or other elemental analysis methods?

ICP‑OES is the better choice when samples have a complex matrix, analyte concentrations are relatively high, and you don’t need isotopic analysis.

What are the detection limits and accuracy levels achievable with ICP-OES at Covalent Metrology?

At Covalent, ICP‑OES can achieve detection limits in the single‑digit parts‑per‑billion range, with relative standard deviation (RSD) typically under 3%.

How is a sample prepared for ICP-OES testing, and what are the minimum volume or concentration requirements?

Solid samples are usually digested or dissolved into a dilute acidic solution. Liquid samples are often diluted in acid, though in many cases they can be analyzed as received.

What kind of data does ICP-OES provide, and how is it typically used in research or quality control?

ICP‑OES provides calibrated, quantitative elemental composition for most elements (excluding atmospheric gases, noble gases, and most halogens). This data is commonly used to confirm stoichiometry, check alloy composition, or identify and quantify impurities in research and quality control.