Choosing between ICP-MS and ICP-OES starts with a measurement requirement. An impressive sensitivity claim is useful only if it helps answer the elemental question in the actual material submitted.
Specify the decision before comparing the instruments
Both techniques use an inductively coupled plasma. ICP-OES measures characteristic emitted light, whereas ICP-MS measures ions separated by mass-to-charge ratio. Their signals and interference problems therefore differ.Thermo Fisher Scientific — Elemental impurities analysis FAQ (opens in a new tab)
The Thermo Fisher technical discussion also distinguishes instrument detection capability from method performance after preparation and dilution. Dilution can move the concentration of interest below the capability of a particular optical-emission method.Thermo Fisher Scientific — Elemental impurities analysis FAQ (opens in a new tab)
For a research-material request, start with named elements and the concentration range that matters to the experiment. “Heavy metals tested” leaves both the analyte list and the meaning of a satisfactory result unresolved.
This article compares how to assess analytical suitability. It does not assign pharmaceutical limits to a research vial or select an instrument from a marketing sensitivity figure.
An optical-emission study shows why element-specific exceptions matter
Støving and colleagues developed an ICP-OES method for 18 elemental impurities in tablets. Their reported detection and quantitation limits were below the historical limits used in that study.Støving and colleagues — ICP-OES quantitation of elemental impurities in tablets (opens in a new tab)
The method nevertheless had a notable exception: osmium showed a memory effect, with recovery and repeatability outside the performance achieved for the other tested elements. The authors identified further development as necessary for that analyte.Støving and colleagues — ICP-OES quantitation of elemental impurities in tablets (opens in a new tab)
This is a useful counterexample to both blanket claims: an optical method was not automatically insufficient, and successful results for most elements did not validate every element.
When reviewing a multi-element panel, look for exceptions hidden behind its overall description. A statement that a platform measures 18 elements does not establish equally reliable quantification of all 18 in every matrix.
An ICP-MS application establishes a defined scope
A 2025 study by Gundogdu and colleagues validated simultaneous sodium, potassium and aluminium measurement in a human albumin solution. It assessed the method for that formulation and reported testing two product batches.Gundogdu and colleagues — Simultaneous ICP-MS measurement in albumin solution (opens in a new tab)
That result supports a specific application of ICP-MS. It does not compare the same peptide powder on both platforms, and it cannot establish universal superiority over ICP-OES.
| Evidence | What to establish |
|---|---|
| Preparation | The reported concentration can be traced back to the original sample. |
| Working range | The prepared sample falls within supported measurement capability. |
| Interference assessment | Other sample components do not create an unresolved target signal. |
| Recovery | The relevant analyte can be measured in the tested matrix. |
The strongest comparison would apply suitable methods to matched samples and evaluate the decision-relevant differences. Comparing results from unrelated formulations is contextual evidence, not a head-to-head trial.
Request a method-level answer
An effective laboratory query states the material, target elements, reporting units and required quantitation level. It then asks which supported method meets those requirements and what limitations remain.
For an illustrative case, a lower instrument detection limit brings no additional decision value if both complete methods already quantify well below the study threshold. Conversely, inadequate quantitation at that threshold cannot be repaired by a prestigious instrument label.
Cost and turnaround can be compared after analytical suitability is established. The conclusion should identify the capable method and its scope, including any element needing a different approach.
Sources and further detail
- Thermo Fisher Scientific — Elemental impurities analysis FAQ (opens in a new tab)
Manufacturer technical document read for detection principles and preparation-dependent capability; regulatory and universal performance claims are not adopted.
- Støving and colleagues — ICP-OES quantitation of elemental impurities in tablets (opens in a new tab)
Original 2013 abstract read. Historical concentration limits and the osmium exception are retained as study-specific findings.
- Gundogdu and colleagues — Simultaneous ICP-MS measurement in albumin solution (opens in a new tab)
Indexed original methods, results and conclusions read; direct PMC retrieval presented a browser check. No peptide-matrix validation is inferred.
Sources checked 20 September 2026. Worked examples are illustrative unless a supplied report is explicitly identified. This article has not undergone independent scientific peer review.