Inductively Coupled Plasma Spectroscopy (ICP)
1. Introduction
Inductively Coupled Plasma (ICP) Spectroscopy is a highly sensitive analytical technique used
to detect and quantify trace and ultra-trace elements in a wide variety of samples—
environmental, biological, pharmaceutical, geological, and industrial.
It employs a high-temperature argon plasma as the excitation source to atomize and ionize
the sample.
ICP can be coupled with Atomic Emission Spectroscopy (ICP-AES/OES) or Mass
Spectrometry (ICP-MS) depending on whether emission lines or ions are measured.
2. Principle of ICP Spectroscopy
Plasma Generation: A radio-frequency (RF) electromagnetic field ionizes a flowing argon
gas, creating an extremely hot plasma (~6,000–10,000 K).
Sample Introduction: The sample—usually as an aerosol—is carried by argon into this
plasma, where it is rapidly desolvated, vaporized, atomized, and ionized.
Detection:
ICP-OES/AES: Measures characteristic wavelengths of light emitted as excited atoms
and ions return to lower energy states.
ICP-MS: Detects mass-to-charge ratios (m/z) of ions using a mass spectrometer,
offering part-per-trillion sensitivity.
3. Major Components of an ICP System
3.1 Sample Introduction System
Nebulizer: Converts liquid sample into a fine aerosol.
Spray Chamber: Removes larger droplets to ensure uniform aerosol flow.
, 3.2 Plasma Torch
Made of quartz tubes with three concentric channels for argon gas flows:
Plasma gas (outer flow) sustains the plasma.
Auxiliary gas shapes and stabilizes the plasma.
Carrier gas transports the aerosolized sample.
3.3 RF Coil and Generator
A radio-frequency coil (commonly 27 or 40 MHz) surrounds the torch.
RF energy induces a time-varying magnetic field that sustains the plasma by inductive
coupling.
3.4 Optical or Mass Detection System
ICP-OES: High-resolution spectrometer with a photomultiplier or CCD detector.
ICP-MS: Interface cones (sampler and skimmer) introduce ions into a high-vacuum mass
spectrometer.
4. Operating Steps
1. Introduction
Inductively Coupled Plasma (ICP) Spectroscopy is a highly sensitive analytical technique used
to detect and quantify trace and ultra-trace elements in a wide variety of samples—
environmental, biological, pharmaceutical, geological, and industrial.
It employs a high-temperature argon plasma as the excitation source to atomize and ionize
the sample.
ICP can be coupled with Atomic Emission Spectroscopy (ICP-AES/OES) or Mass
Spectrometry (ICP-MS) depending on whether emission lines or ions are measured.
2. Principle of ICP Spectroscopy
Plasma Generation: A radio-frequency (RF) electromagnetic field ionizes a flowing argon
gas, creating an extremely hot plasma (~6,000–10,000 K).
Sample Introduction: The sample—usually as an aerosol—is carried by argon into this
plasma, where it is rapidly desolvated, vaporized, atomized, and ionized.
Detection:
ICP-OES/AES: Measures characteristic wavelengths of light emitted as excited atoms
and ions return to lower energy states.
ICP-MS: Detects mass-to-charge ratios (m/z) of ions using a mass spectrometer,
offering part-per-trillion sensitivity.
3. Major Components of an ICP System
3.1 Sample Introduction System
Nebulizer: Converts liquid sample into a fine aerosol.
Spray Chamber: Removes larger droplets to ensure uniform aerosol flow.
, 3.2 Plasma Torch
Made of quartz tubes with three concentric channels for argon gas flows:
Plasma gas (outer flow) sustains the plasma.
Auxiliary gas shapes and stabilizes the plasma.
Carrier gas transports the aerosolized sample.
3.3 RF Coil and Generator
A radio-frequency coil (commonly 27 or 40 MHz) surrounds the torch.
RF energy induces a time-varying magnetic field that sustains the plasma by inductive
coupling.
3.4 Optical or Mass Detection System
ICP-OES: High-resolution spectrometer with a photomultiplier or CCD detector.
ICP-MS: Interface cones (sampler and skimmer) introduce ions into a high-vacuum mass
spectrometer.
4. Operating Steps
