History and Prospects of the Development of Sorbents and Instruments for Ion Chromatography in Russia

Abstract

According to artificial intelligence (which is increasingly becoming a part of our lives), the annual market for chromatography equipment is approximately 100,000 units per year. Unfortunately, sales (and, consequently, usage) of these instruments are unevenly distributed. Russia accounts for only approximately 1% of global sales. This, of course, is neither encouraging nor in keeping with Russia's global role.

In the USSR, it was decided to develop and promote the use of ion chromatography in analytical practice in 1982. However, there were no instruments, no methodology, and no sorbents. What were the characteristics of science and instrumentation at that time? There were undeniable advantages and disadvantages. It was a large, centralized industry. Dozens of specialized research institutes and factories were successfully operating. Production focused on industrial and military applications (nuclear, chemical, and space). There was a strong scientific base, combining classical universities with powerful industry research institutes. However, there was a lack of integration and technological lag. Access to new technologies (electronics, detectors, software) was limited. There was a clear lag in materials science and production flexibility, as well as in the design and precision of materials processing. Automation and production organization were lacking. However, it should be noted that they were able to do something at that time: sensibly and reasonably divide a complex task into more or less non-overlapping subtasks, select teams capable of solving them, set deadlines, personalize responsibility, and demand unconditional fulfillment. This article examines the main groups working on the project. As a result of such cooperation, the task of introducing ion chromatography into analytical practice was accomplished remarkably quickly and effectively. Within a year (by 1983-1984), the first ion chromatographs (Tsvet-3006) were manufactured, domestic anion exchangers (HIKS-1, ANIEKS) were created, and methods for determining anions in water were developed. The results were fully consistent with the best international analogues at the time.

However, with the collapse of the Soviet Union, sorbent synthesis ceased. Old stocks were still used until sometime in the 1990s, but then their shelf life expired and they became unusable. In the 2000s, imports boomed, and everyone working in this field switched to foreign anion exchangers, which were rapidly developing and improving. In Russia, the synthesis of new sorbents was carried out only for scientific purposes, and even then, intermittently. However, extensive practical experience was accumulated.

The synthesis of modern anion-exchange stationary phases for ion chromatography is an extremely complex, labor-intensive, and time-consuming task. From the reagents to the finished column, up to 30 chemical steps can be counted. Failure at any stage can lead to the inoperability of the entire batch of sorbent.

This article presents the main types of anion-exchange materials, the years of their development, and their advantages and disadvantages. A possible way to overcome these disadvantages may be to coat a styrene-divinylbenzene matrix with layers of graphene oxide, followed by functionalization of the material. This article discusses a promising route to synthesizing ion-exchange sorbents with high selectivity and efficiency based on a styrene-divinylbenzene copolymer with an adsorbed layer of graphene oxide with an increased number of epoxy groups. Approaches to the formation of anion exchangers and the anchoring of a hyperbranched layer are proposed. The predominant contribution of ion exchange to the mechanism of separation of polarizable and highly polarizable ions on sorbents is revealed. Further improvement of the stability of the sorbents requires covalent anchoring of graphene oxide to a polymer or silica gel matrix.