Purite has provided the ion chromatography unit at Aston University with a customised Select Fusion water purification system, enabling researchers to achieve consistently accurate test results.
Ion chromatography (IC) is a subdivision of high performance liquid chromatography (HPLC).
HPLC is an analytical technique based on the separation of a mixture in solution using a liquid mobile phase to carry the mixture through a chromatographic column, which separates the components of the mixture by selective absorption.
Ion chromatography is used to determine the concentration of ionic species in a solution by separating them out based on their relative atomic mass and ionic charge.
Solutions to be analysed are injected into a column containing a specific ion-exchange absorbent resin; to determine the presence of cations, a cation-exchange resin column is used and for anions an anion-exchange resin column is required.
As the solution passes down through the reaction column, under pressure, the dissolved ions from the solution are absorbed onto the exchange sites on the resin in a specific order, with the heaviest ions with the higher number of charges first.
Following the loading of the column with the sample solution, an eluent solution is then passed through the column which displaces the absorbed ions off into distinct concentration bands.
As these bands of ions come through, the conductivity of the eluted solution is measured and expressed graphically as a peak against retention time.
The peak heights are then compared to a calibrated standard to determine actual ion concentrations.
For the process to be carried out effectively a consistent supply of high quality purified water is required to carry the mixture through the column without introducing impurities that could affect the results.
Dr Anisa Mahomed, a researcher at the university, explained, "Prior to implementing the Purite solution, we had encountered a number of problems with obtaining consistent and accurate test results.
We were carrying containers of purified water across campus to the laboratory, resulting in carbon contamination on route, which prevented us from achieving a steady base line when testing.
"We needed a solution that would offer us a supply of 18.2megohm water in the lab, enabling us to carry out experiments with the knowledge that the water was pure.
Having had excellent results with Purite equipment elsewhere in the university, we asked them to offer us a solution." Following close collaboration with the laboratory staff and students, Purite offered its Select Fusion system, modified to provide a constant recirculation flow to the laboratory's ion chromatography equipment.
By providing a continuous flow of purified water to the reservoir, the water in the reservoir is constantly maintained at 18.2Mohm-cm.
The Select Fusion is a dual grade purification unit, specifically designed for use in demanding analytical laboratory and life sciences applications.
In addition to providing the ion chromatography reservoir with one litre/minute of 18.2megohm water, the unit is able to provide water at a purity of 1-10megohm via the Fusion's integral 15 litre storage tank for general laboratory duties, meeting all the laboratory's pure water needs on-site and in one compact unit.
The system incorporates pre-treatment, reverse osmosis, ion exchange and photo-oxidation purification techniques in a robust enclosure, with a front panel mounted LCD control panel, helping the students to carry out experiments simply and efficiently.
The LCD panel clearly displays the system status and parameters such as water quality, total organic carbon (TOC) and temperature, with visual and audible alarms to alert users of any discrepancies so that action can be taken immediately and test results salvaged.
Anisa Mahomed is pleased with the results: "The Purite system has made life so much easier, giving us a consistent and dependable supply of 18.2Mohm-cm water in the lab.
"It has effectively eliminated the earlier problems we were having with impurities in the water affecting test results, enabling us to achieve accurate results every time.
"Purite's knowledge and expertise has been essential to us in achieving this."
