Ion chromatography (IC) is an instrumental technique used extensively in the environmental, pharmaceutical, life sciences, biotechnology, chemical, petrochemical, food and beverage, power generation, and electronics industries. Applications include anion and cations, carbohydrates, organic acids, amino acids, proteins, peptides, oligonucleotides, oxyhalides, carboxylates, polysaccharides, polyphosphates, fatty acids, metals, phenols, surfactants, and ethanolamines.
As IC continues to develop, the number of ion-exchange materials developed for IC has increased, facilitated by the understanding of the process taking place at the surface of the stationary phase.
As IC continues to develop, the number of ion-exchange materials developed for IC has increased, facilitated by the understanding of the process taking place at the surface of the stationary phase.
Depending on the separation mode (ion exchange, ion exclusion or ion pair), different types of stationary phases are used.
Ion-Exchange Chromatography–is used for the separation of both inorganic and organic anions and cations.
Ion-Exclusion Chromatography –is used for the separation of weak inorganic and organic acids from completely dissociated acids that elute as one peak within the void volume of the column. In combination with suitable detection systems, this separation method is also useful for determining amino acids, aldehydes, and alcohols.
Ion-Pair Chromatography –is used for the separation of surface-active anions and cations, sulfur compounds, amines, and transition metal complexes.
Separation method for the ion chromatography system respondents are currently using or planning to use:
| Chemical suppression detection | 33% |
| Electrolytic suppression detection | 19% |
| Ion suppression chromatography | 39% |
| Electronic suppression detection | 7% |
| Other | 2% |
Ion chromatography instruments closely resemble conventional HPLC, where typical components include an autosampler, a high pressure pump, an injection valve with a sample loop of suitable size, a guard column, an analytical column, a flow-through detector, and a data system, which can be of varying complexity.
Respondents selected the following components with their ion chromatography system.
| Chromatography software | 40% |
| Automatic sampler | 30% |
| Chemical suppressor | 21% |
| Automatic dilution/filtration/dialysis | 9% |
With a sensitive technique such as IC, the effects of contamination have serious consequences, with the potential to negate experimental results. The effects of contamination from ions, organics, colloids, bacteria, and gases can all impact sensitivity and reproducibility to some degree. Contaminating ions tend to have a significant but short-term effect, producing high blanks, high background, and chemical interferences that directly degrade results and reduce sensitivity. Varying levels of contaminating ions would result in higher variances in the observed results. While organics, colloids, and bacteria will also affect background/ blanks, they also tend to have a long-term impact through media fouling and surface coating that can affect parts of the instrumentation, such as the chromatography column, the detector, or inner surfaces of the system itself. The net effect of this type of fouling is anomalous baseline shifts, unknown peaks on the baseline, high noise etc.
When choosing a laboratory water purification system for analytical applications such as IC, it is essential to consider systems that combine such technologies and incorporate realtime monitoring of water purity in order to have confidence in the water and confidence in the experimental results.
According to the respondents, ionic and organic are the most common types of contaminants experienced in their IC applications.
| Ionic | 29% |
| Organic | 23% |
| Particulate | 11% |
| Strong acid or base | 10% |
| Bacterial | 4% |
| Gaseous | 4% |
| Don’t know | 8% |
| Other | 1% |
Dionex is the marketshare leader in IC, but there are a few other choices to consider – Metrohm, Waters, Shimadzu, Cecil Instruments, and Bio-Rad. The most important consideration in the purchase of an IC is making sure that the system you are looking at has a proven track record for the analysis you want to do.
IC systems offer a number of advantages that are important to respondents in their purchasing process: quality of data, speed, sensitivity, and increased lab throughput. With the introduction of high efficiency separator columns for ion-exchange, ion-exclusion, and ion-pair chromatography, the average analysis time could be reduced. Therefore, quantitative results are obtained in a fraction of the time previously required for traditional wet-chemical methods, thus increasing the sample throughput.
Top 12 features/factors that influence the buying decision
| Accuracy/Quality of data | 94% |
| Sensitivity | 89% |
| Speed | 85% |
| Ease of maintenance | 85% |
| Increase lab throughput | 83% |
| Resolution | 83% |
| Service and support | 79% |
| Safety | 72% |
| Warranties | 72% |
| Easy transfer of methods | 70% |
| Price | 70% |
| Training | 70% |
Completed Surveys: 173
For more information on Ion Chromatography, visit www.labmanager.com/IC
