Electrolytic suppressors are the easiest to use on the market. They make their own regenerant inside the suppressor directly with water in one of two ways: in recycled eluent mode or external water mode. In recycled eluent mode, the water used for regeneration comes from recycled suppressed eluent, making this mode of operation the easiest to use. In external water mode, the water is delivered from an external source either pneumatically using pressurized gas, using a second pump, or with a direct feed from a deionized water system (with flow-rate regulator). However you choose to set it up, your users won’t have to prepare any reagent.
Chemical suppressors do sacrifice some ease of use compared with the electrolytic suppressor, since they require manually prepared chemical regenerant, but the regenerant is passed through a parallel channel, allowing for continuous regeneration.
Packed bed suppressors are based on decades old technology first developed in the 1970s. This type of suppressor has a finite capacity and must be taken offline to regenerate. One work around is the rotating packed bed suppressor—this is three suppressors in one that rotate between analyses. While one suppressor is used in the analysis, the second one is being regenerated and the third is being rinsed. This poses several problems, including some drift as the suppressor slowly exhausts, and the possibility that for analyses with long run times, the in-use suppressor cartridge will exhaust before the analysis is complete. The biggest issue is with validation.
The lifetime of electrolytic suppressors is shorter because the technology we use to make a suppressor that doesn’t require regenerant is a little more sensitive to the eluents and samples the suppressor encounters. Not having to use sulfuric acid means additional convenience and safety for our customers. For those who prefer chemical suppression, we still offer that as an option.
Suppressors need to be replaced at regular intervals because they come into direct contact with eluent and sample material and eventually become depleted and need to be discarded. For most our customers, it makes more sense to replace these at regular intervals than it does to have the instrument downtime required to verify and warranty these items.
For example, competitor warranties have several stipulations that don’t make sense for most labs—they require that the suppressors not be used continuously, a rigorous verification process, that all system maintenance be performed by the system manufacturer (at the owner’s expense after the first year, including field service engineer travel), and that the suppressor be sent back to the manufacturer at the customer’s expense. This makes the warranty extremely costly for the customer and requires lengthy system downtime that is unacceptable for most of our customers.
For customers who feel more comfortable with a warranty, we offer a 5-year extended warranty on our chemical suppressors and a 2-year extended warranty on our electrolytic suppressors.
We strive to limit the number of chemicals in your lab to help reduce disposal costs and for the health and safety of our customers. Packed bed cation suppressors can use Nitric acid with trace amounts of rubidium—classified as hazardous waste, which is expensive to dispose. Packed bed anion suppressors require sulfuric acid for regeneration. This is also expensive to dispose of and poses a health risk to operators.
We offer different types of suppressors so that we can support the widest range of applications with the best performance.
No. In addition to eliminating the need to dispose of hazardous waste, newer suppressor technology offers several other maintenance savings. For example, when competitor suppressors are exposed to certain contaminants, they cannot be regenerated by normal means—each suppressor unit must be rinsed until it is exhausted, which can take up 12 hours to regenerate all three cartridges. The accompanying peristaltic pump also requires routine maintenance, including replacing the tubing every six weeks or regenerant flow will drop, leading to excess drift and loss of peak recoveries.
We offer high efficiency suppressors with high capacity and high efficiency columns—this gives you the best detection limits and the ability to handle complex samples.
No. The biggest concern with validated methods is multiple suppressor cartridges, because they must all be validated separately, and the operator must keep track of which suppressor cartridge was used for each analysis. In strictly validated environments, only one suppressor cartridge can be validated, which can greatly reduce throughput in systems with multiple suppressor cartridges—the second and third cartridges cannot be used for analysis and the entire system is idle during regeneration and rinsing of the operational suppressor.
All Thermo Scientific Dionex suppressors use a single suppressor that requires one-off validation, with only one system-level calibration and blank per analytical sequence.
We get it, you want to get right to the analysis as quickly as possible. Luckily, once properly hydrated, our suppressors can run continuously without any interruptions. Older suppressor technology requires a lot more steps—regenerant preparation, preparation of a flush solution, pump maintenance—which can lead to long start-up times and down-times.