Electroeluent generator is a key component of the new generation of ion chromatography system and one of the two major components of reagent-free ion chromatography system. The electro-eluent generator can transform pure water into potassium hydroxide solution which is positively related to applied current on line. It can fundamentally eliminate many shortcomings of manual preparation of eluent, such as time-consuming, impurities, human error and so on. At the same time, the automation level of the system is significantly improved.
According to the different structure, the eluent generator can be roughly divided into two types: single-film type and double-film type. Single membrane type means that only one type of ion exchange membrane is used to separate the high-pressure eluent channel from the low-pressure reserve chamber, and one of the electrodes is directly placed in the high-pressure eluent channel. When the generator works, the eluent produced in the high-pressure eluent channel is accompanied by a large amount of electrolytic gas, so the eluent needs to be removed by a degassing device before it enters the downstream chromatography. Because the raw materials used for degassing are extremely expensive, the use of degassing device significantly increases the cost of the system, but also increases the dead volume of the system, and increases the delay of gradient elution.
To solve these problems, Professor Yang Bingcheng of East China University of Technology introduced a leachate generator based on double membrane structure. The double-membrane type uses cation exchange membrane and bipolar membrane to separate the electrolyzer from the eluent generator, and the eluent channel is completely separated from the two electrodes in space. The electrolyte gas generated by the generator only exists in the electrolytic cell, but does not enter the eluent channel, thus avoiding the use of the degassing device and eliminating the defects caused by the degassing device. At the same time, it generates high purity potassium hydroxide, which can well match the existing ion chromatography system regardless of the concentration range or pressure range of the eluent produced.