Overview
This lecture explains the working principle of ICP-OES spectrometers and describes their role in analyzing the elemental composition of various samples.
Purpose and Principle of ICP-OES
- An ICP-OES spectrometer is used to analyze the elemental composition and concentration in substances.
- The sample is converted into light, which is then measured to determine elemental quantities.
- The instrument uses extremely hot plasma to excite atoms and ions, causing them to emit light.
- The intensity of the emitted light correlates with the concentration of specific elements.
How ICP-OES Spectrometers Work (Step-by-Step)
- The sample solution enters the spectrometer via a peristaltic pump.
- In the nebulizer, the liquid sample is converted into an aerosol (fine mist).
- The spray chamber removes larger droplets, allowing only small droplets to pass into the plasma.
- Inside the plasma, the sample aerosol evaporates and atoms/ions become excited, emitting light.
- The emitted light is collected and dispersed into individual spectral lines by the optics system.
- The detector array records the wavelength and intensity of the emitted light.
- Specialized software calculates the concentrations of elements from these measurements.
Features of High-End ICP-OES (e.g., SPECTRO ARCOS)
- Features high-resolution, purge-free, sealed optical systems for accurate measurements.
- Especially suitable for high-load laboratory environments due to reliability and precision.
Key Terms & Definitions
- ICP-OES — Inductively Coupled Plasma Optical Emission Spectroscopy, a technique for detecting elements using plasma and optical measurements.
- Plasma — Extremely hot, ionized gas used to excite sample atoms and ions.
- Nebulizer — Device that turns a liquid sample into an aerosol.
- Spectral Line — Unique wavelength of light emitted by an excited atom or ion, characteristic of each element.
Action Items / Next Steps
- Review the step-by-step process of sample introduction and analysis in ICP-OES.
- Become familiar with the terms and functions of spectrometer components.