Ion Chromatography
IC (Ion Chromatography) separates and quantifies inorganic anions and cations in a sample based on their affinity for an ion-exchange stationary phase.
O que é IC
How Ion Chromatography Quantifies Inorganic Anions and Cations
IC (Ion Chromatography) is a separation technique in which a liquid sample is passed through a column packed with an ion-exchange resin, where dissolved ions such as chloride, sulfate, nitrate, sodium and other anions or cations separate based on the strength of their electrostatic interaction with the resin and elute at different retention times. A conductivity detector, often after a suppressor stage that lowers the background signal from the eluent, then measures each ion as it elutes, giving both identification and precise quantification down to sub-ppm levels. IC is the standard method for inorganic ion analysis in water, formulations and raw materials where atomic techniques like ICP or AAS do not apply, since those measure elements, not the specific ionic species present.
What sets us apart
We don't hand over a spectrum. We hand over the interpretation.
Any lab can return peaks and numbers. Our report reads the data. Three differences define what we deliver — illustrated below with a real, anonymized case.
Multiple techniques, one integrated report
We don't hand back five loose reports. We cross-reference every technique's results into a single reading — each signal checked against the others — to reach an answer, not a pile of data.
- Contamination investigation — identifying and tracing the source of a foreign species.
- Performance degradation — explaining why a batch behaves outside expectations.
- New supplier validation — proving equivalence before switching.
3 LDPE batches · 4 techniques converge, NMR reveals the difference
In semicrystalline polymer systems, thermomechanical processing variables influence chain conformational dynamics¹. Solid-state NMR resolves chemical environments at the nanometer scale², sensitive to changes not detectable by XRD or FTIR³.
Technical justification anchored in the literature
Every technique choice and every inference in the report is backed by peer-reviewed literature — with citations in the text. The conclusion isn't loose opinion: it's a traceable argument, defensible in an audit and in front of the client.
- Numbered citations linking claim to source
- Official standards and methods referenced per analyte
- Auditable reasoning end to end
Conclusion and expert opinion
The report closes with a clear position, signed by the Principal Investigator: what the data shows, what can't yet be claimed, and the next step. It includes an honest caveat on the limits of inference — what separates a technical opinion from a guess.
- Explicit technical position, not just results
- Inference limits declared honestly
- Next-step recommendation signed by the P.I.
Four techniques confirmed equivalence; only the solid-state NMR revealed the subtle conformational change not distinguishable by conventional QC — a molecular signature consistent with the atypical filtration behavior.
Without the industrial line's parameters, no direct causal correlation can be established — a complementary step is recommended for elucidation.
Aplicações de mercado
Onde a IC entrega resultados
Market Applications
FAQ
Frequently Asked Questions about Ion Chromatography (IC)
What does ion chromatography (IC) measure that other chromatography techniques don't?
- IC is specifically designed to separate and quantify inorganic and small organic ions — such as chloride, sulfate, nitrate, phosphate, sodium, potassium, calcium and ammonium — based on their interaction with an ion-exchange resin, a separation mechanism that GC and conventional LC are not optimized for.
What kind of detector does IC typically use?
- IC most commonly uses suppressed conductivity detection, which measures the electrical conductivity of separated ions after a suppressor reduces background conductivity from the mobile phase — giving high sensitivity for ions that otherwise have no useful UV absorbance or other easily detected property.
Can IC analyze both anions and cations?
- Yes, though typically in separate runs with different columns and eluents optimized for each — one method and column set targets anions (like chloride, sulfate, nitrate), and another targets cations (like sodium, potassium, calcium, ammonium).
What is combustion ion chromatography used for?
- Combustion IC first burns the sample to convert halogens (such as chlorine, bromine, fluorine) and sulfur into their ionic forms, which are then trapped and quantified by conventional ion chromatography — a standard approach for determining total halogen or sulfur content in a sample, including in contexts such as extractables/leachables and elemental impurity screening, without needing to identify each individual compound contributing to that total.
What are typical applications of ion chromatography?
- Common applications include water quality testing (anion/cation profiles), pharmaceutical counter-ion identification and quantification in salts, and screening raw materials or formulations for specific inorganic contaminants.
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