Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES)

Overview

Inductively-coupled plasma optical emission spectrometry is a technique used to measure the elemental composition of a material by evaluating characteristic elemental spectra emitted during plasma heating.

The instrument can be used for the measurement of marine and freshwater samples (including seawater, pore water, river water, and lake water) and dissolved geological materials. For water samples measurements include the simultaneous determination of major and minor dissolved elements. For dissolved geologic materials measurements include the elements making up the major oxides, minor elements, and several trace metals that surpass the limits of detection. ICP-OES analytical results are heavily matrix dependent, thus the suite of elemental analytes may be adjusted depending upon the material sampled.

Instrument Make & Model

Agilent 5110 ICP-OES

Estimated Measurement Time

Sample Preparation: ~3 hours
Sample Measurement: ~50 samples/hour

Quantity of Sample Material

solids: 100 - 500 mg per sample
liquids: 100 uL – 10 mL per sample; dependent on dilution

Principles & Analytical Capabilities

Dissolved sample flows through an introduction system in which the component molecules are desolvated, atomized and excited within an argon plasma. The transfer of energy from electronic and atomic collisions within the plasma excites elemental valence electrons across various atomic and ionic orbitals, which in turn release characteristic photons during electron de-excitation. Portions of these photons are directed through an optical chamber and ultimately fall upon a diffraction grating where they are reflected at angles determined by their wavelengths, separating them, like a prism, into discrete spectral orders. The photons impinge on an accurately aligned CCD or CMOS detector chip, and thus are mapped to a 2-D pixel array. A given element concentration is determined by locating its spectra within the array (i.e. on the chip), integrating the spectral intensity over a short time interval and comparing the results against a calibration curve of certified reference material.

Data Generated

Data components:

Major cations measured: Na, Ca, Mg, K
Minor elements measured: B, Ba, Li, Mn, Fe, Sr
Trace elements measured: Al, Br, Sc, Y, Si, Ti, Cr, Ni, V, Zr, Zn, Cu, Co, Nb, Ge
For water samples, data provided in μM or mM. For sediment/rock samples, wt% or ppm.

Data files:

Concentrations (CSV): tabular file of calculated concentration results of elements requested by the user.

Raw files:

Expanded Results (CSV): tabular file of raw concentration results including individual elements and wavelengths (nm), raw intensities, standard deviation and relative standard deviation.

Data Example

Interstitial water sample measurements of calcium, manganese, strontium, silicon, and barium from Hole U1607A of IODP Expedition 400 in the northwest Greenland glaciated margin.¹

Procedures & Manuals

References

¹Knutz, P. C., Jennings, A. E., Childress, L. B., Bryant, R. M., Cargill, S. K., Coxall, H. K., Frank, T. D., Grant, G. R., Gray, R. E., Ives, L., Kumar, V., Le Houedec, S., Martens, J., Naim, F., Nelissen, M., Özen, V., Passchier, S., Pérez, L. F., Ren, J., … Zimmermann, H. H. (2025). IODP Expedition 400 ICP-AES elemental analysis (interstitial water) [Data set]. International Ocean Discovery Program. https://doi.org/10.5281/zenodo.15366867