At the beginning of the last century, a new term was introduced into the scientific nomenclature - CHROMATOGRAPHY. Creator of Mikhail Semenovich Tswiett, a professor of botany at the University of Warsaw (Poland), certainly did not expect that the technique he discovered would play such an honorable role in discoveries made, formulating new laws and hypotheses in order to understand the world.

In modern analytical chemistry in the 21st century, separation techniques still play a dominant role. Of course, theoretical achievements based on various physicochemical processes and phenomena’s are still valid, and chromatography has become the dominant method of separation and identification in the natural sciences.

This applies not only to the scale and scope of the project or the method of its implementation, but also to the awareness of people using existing knowledge and technical progress. Hence, conferences, symposiums and/or workshops devoted to this issue are organized in many countries in Europe and around the world. They are organized by formal and informal organizations working together to coordinate, popularize and raise the scientific level of this important branch of chemistry.

The origin of the International Symposia on Separation Sciences (ISSS) can be found in the national gas chromatography scientific meetings held in Croatia in Zagreb from 1967 and later at Plitvice Lakes until 1988. Over the years these meetings have grown to include all chromatographic and other separation techniques. Jože Marsel from Ljubljana, Slovenia, and Srećko Turina from Zagreb, Croatia, came up with the idea to organize joint Slovenian-Croatian meetings on chromatography. Starting from 1990, these scientific meetings have become international being alternatively organized in Bled, Slovenia, and in Opatija, Croatia, until 1998. In spite of the war involving part of Croatia, the organizers decided to continue these meetings which were supported mostly by Slovenia, but also by many scientists from abroad. 

The first such meeting took place in 1990 in Bled, Slovenia, and the next in 1992 in Opatija, Croatia. Later, Jože Marsel and Srećko Turina decided to also invite participants from other countries. In the course of the welcome dinner before symposium in Bled 1994, Jože Marsel and Srećko Turina met the invited speakers Szabolcs Nyiredy from Budapest, Hungary, and Dušan Berek from Bratislava, Slovakia. They exchanged information about the situation in scientific research and education in their countries in general and in the separation sciences in particular. Jože Marsel discussed plans for future meetings and their possible internationalization. The debate continued next evening with attendance of Vratislav Švob from Zagreb, Croatia, and Branko Nikolin from Sarajevo, Bosnia-Herzegovina. Szabolcs Nyiredy informed about his intention to organize in Siofók every two years symposia under auspices of the Hungarian Society of Separation Sciences which he had just founded. Jože Marsel presented his readiness to help organize the next Croatian-Slovenian symposium on chromatography in Opatija in 1996. Srećko Turina informed that he could not take part in the organizational work and Vratislav Švob proposed Nikola Šegudovič from Zagreb as a suitable organizer from the Croatian side. He was accepted and eventually became the most active meeting organizer. It was agreed that a group of organizers of these symposia will create a joint Steering Committee. Next night, the name of the future joint organism was discussed along with its mission and basic rules of operation. During the 4^th ISSS in Opatija, Croatia, in October 1996, was born the idea of extending the mutual scientific cooperation by inviting the corresponding societies from Bosnia and Herzegovina, Hungary and Slovakia with the help of the nominated Steering Committee (Dušan Berek, Bratislava – Slovak Chemical Society; Jože Marsel, Ljubljana – Slovenian Chemical Society; Szabolcs Nyiredy, Budapest – Hungarian Society for Separation Sciences and Nikola Šegudović, Zagreb – Croatian Society of Chemical Engineers). This idea became true at the 5^th ISSS held in Bled, Slovenia, in October 1998, when the Central European Group for Separation Sciences (CEGSS) was founded under the leadership of the Steering Committee formed by Dušan Berek, Jože Marsel, Branko Nikolin, Szabolcs Nyiredy and Nikola Šegudović. The name “Central European Group for Separation Sciences” was proposed by Szabolcs Nyiredy and it was accepted. Following the discussions, it was concluded that the CEGSS would also include several other member countries. Jože Marsel proposed Italy with Corrado Sarzanini as representative of the Italian Chemical Society, and Austria with Wolfgang Buchberger as representative of the Austrian Society for Analytical Chemistry. Dušan Berek proposed Czech Republic with Pavel Jandera as representative of the Czech Chemical Society, and Poland with Bogusław Buszewski as representative of the Polish Chemical Society. He also suggested to consider Serbia, Bulgaria, Romania and Ukraine as possible members. Following discussions, the extension of the CEGSS by including the last four countries was postponed. Jože Marsel and Dušan Berek considered necessary to address the Chemical Societies of corresponding countries to accept their mentioned representatives. The rules of operation were outlined and their principles accepted.

Remembering the successful Bratislava symposia on chromatography, which had been organized in the sixties and seventies and had attracted large international audience, Dušan Berek suggested that a series of symposia devoted to separation sciences should be in turn arranged in several Central European countries. The proposal was accepted. During the 3^rd Balaton Symposium held in 1999 in Siófok, Hungary, the CEGSS was extended by the Czech Chemical Society with Pavel Jandera from Pardubice as representative. Szabolcs Nyiredy promised that some of his Siofók symposia can also be included in the CEGSS series, starting with 2003.

In the year 2000, during the 6^th ISSS at Plitvice Lakes, Croatia, the following three societies joined CEGSS: Austrian Society for Analytical Chemistry with Wolfgang Buchberger from Linz as representative, Italian Chemical Society with Corrado Sarzanini from Torino as representative, and Polish Chemical Society with Bogusław Buszewski from Toruń as representative. It has been decided that the joint meetings organized by the CEGSS Steering Committee will be called International Symposia on Separation Sciences (ISSS).

With just small adjustments, the original Rules of Operation are still valid and they are specified in the attached Mission and Rules of CEGSS. It was also agreed that the Steering Committee would meet at least once a year to determine the directions and priorities of the activities. For organizational reasons and a better coordination, Dušan Berek proposed the appointment of an annual rotating chairman to organize the ISSS symposium in a given year, namely in the person of the representative of the country where the ISSS symposium is organized, and a secretary to represent the group in organizational matters, responsible for the administrative and documentation work of the CEGSS. Both proposals were accepted, in accordance with the Mission and Rules, with elections for five years. It turned out that it was a good decision, and the work within the group picked up the pace. At the request of Dušan Berek, with the support of Pavel Jandera and Bogusław Buszewski, Nikola Šegudović was elected as the first secretary of CEGSS at the 12^th ISSS 2006, Lipica, Slovenia. He was particularly ambitious and consistent in organizing this series of symposia. He established cooperation with the industry and signed a long-term sponsorship contract.

An important task set by the Steering Committee, also in accordance with the assumptions and rules of the mission, was to maintain the organization of events under the CEGSS umbrella, with registration fees as low as possible and a high scientific and organizational level. This fact is all the more important as the prices of ”commercially” organized scientific meetings have increased exorbitantly, making it impossible for colleagues from Eastern, Northern and Central European countries to participate. This applies especially to PhD students and young researchers even though projects such as: Analytica, InCom, ISC and HPLC and others offered the so-called travel grants, but their number was significantly limited.

ISSS symposia are focused on the fundamental and practical aspects of separation and detection methods, sample preparation for analysis, as well as related or hyphenated, multidimensional and miniaturized techniques for analytical, preparative and applied purposes in various fields such as environmental, food, natural products, pharmaceutical and clinical, forensics, industry, chemometrics and so on, including new horizons and challenges in separation sciences. They connect scientists and users of chromatography, electrophoresis and separation techniques from academia and industry around the world, giving young researchers the opportunity to learn more about current progress in separation sciences, to present the latest results of their work and to establish new collaborations. The scientific programme includes plenary and keynote lectures by invited speakers, oral presentations, flash-orals and posters by senior scientists and young researchers. This means stable activity of the members of the Steering Committee and national committees of the countries associated in CEGSS.

Following these, our plans became active, which was undoubtedly due to the effort to organize the ISSS events at a good level, with the participation of internationally recognized scientists in the field of separation sciences. Szabolcs Nyiredy, Hungary, Josef Schmidt and Wolfgang Buchberger, Austria, as well as Corrado Sarzanini, Italy, have shown exceptional activity in this area. The appointment of Bogusław Buszewski to the EuCheMS presidium and the establishment of cooperation with the European Society for Separation Science (EuSSS) [1,2], under the leadership first of Hartmut Frank from Bayreuth, Germany, and then of Bogusław Buszewski from Toruń, Poland, proved here also helpful.

The support of Wolfgang Lindner and Günter Bonn from Austria and Klaus Unger, Klaus Albert, Imre Molnar and Ernst Bayer from Germany, as well as Christ Boven from United Kingdom, Francesco Dondi from Italy and Jozef Lehotay from Slovakia has contributed to the promotion and popularization of chromatography and related separation methods in Europe and around the world. The organization of subsequent symposia in the ISSS series turned out to be a success. In addition, there was a generational change in the representatives of some individual countries. Thus, Lucija Zupančič-Kralj replaced Jože Marsel, who retired, in September 2002 at the 8^th ISSS in Toruń, Poland, and Imre Klebovich replaced Szabolcs Nyiredy, who passed away, in June 2007 at the 13^th ISSS in Štrbske Pleso, Slovakia. CEGSS, however, continued to develop. Within the 13^th ISSS in Štrbské Pleso, High Tatras in Slovakia, at the CEGSS Steering Committee meeting from June 28, 2007, Dušan Berek proposed and the Steering Committee unanimously accepted future contacts to include new CEGSS members, namely Lithuania and Ukraine in 2007 and Romania in 2008. At the CEGSS Steering Committee meeting on October 1, 2008, during the 14^th ISSS in Primošten, Croatia, two new CEGSS members were accepted: the Ukrainian Chromatographic Society with Modest Gertsiuk from Kiev as representative became the 9^th member of CEGSS and the Romanian Chemical Society with Virginia Coman from Cluj-Napoca as representative became the 10^th member of CEGSS.

At this meeting, at the request of Bogusław Buszewski, a prize (medal and diploma) was established for services to CEGSS, especially for organizing the ISSS symposia and the contribution to the promotion and popularization of separation sciences [3].

At beginning of September 2012, Nikola Šegudovič passed away. At the Steering Committee meeting on September 11, 2012, during the 18^th ISSS in Toruń, Poland, Bogusław Buszewski announced that some CEGSS members could not continue their activity and proposed the adoption of new members in the CEGSS Steering Committee and the election of a new secretary to maintain the high efficiency of CEGSS. Therefore, in this Meeting a new generational change took place: in Croatia, Nikola Šegudovič was replaced by Tomislav Bolanča, and due to retirement in Italy, Corrado Sarzanini by Danilo Corradini and in Slovenia Lucija Zupančič-Kralj by Irena Vovk. Dušan Berek was elected the new CEGSS secretary. All proposals were unanimously accepted. At the Steering Committee meeting on September 25, 2013, during the 19^th ISSS in Poreč, Croatia, Dušan Berek, the CEGSS secretary, suggested the necessity of some changes in the leadership of CEGSS. He proposed to elect a president for five years to coordinate and to develop all activities together with the secretary and the annual chairman in charge, forming the Executive Steering Committee (Presidium) of CEGSS. All members of the CEGSS Committee agreed with this proposal and entrusted Bogusław Buszewski with the position of the president of CEGSS for the period of 2013–2018. Then, in 2016, during the 22^nd ISSS in Toruń, Poland, there was another generational change: in Austria, Wolfgang Buchberger was replaced by Erwin Rosenberg and in Slovakia, Jozef Lehotay by Milan Hutta.

In 2018, during the 24^th ISSS in Jasná, Slovakia, at the Meeting of the Steering Committee from June 19, 2018, Bogusław Buszewski proposed the appointment of Dušan Berek, the oldest member of the Steering Committee, as the Honorary President of CEGSS, in recognition of his commitment and activity for over twenty years. Virginia Coman, Romania, was elected the next Secretary of CEGSS and Bogusław Buszewski was re-elected as president of CEGSS. These amendments were approved unanimously. 

The last ISSS symposium, the 25^th edition, before the Corona-Virus pandemic took place in Łódź, Poland, in September 2019. After a break of more than ten years, a new member joined the CEGSS, namely the Serbian Chemical Society, with Živoslav Tešič from Belgrade as its representative. The decision was taken at the Steering Committee Meeting on September 15, 2019, at the 25-ISSS in Łódź, Poland. Other countries proposed by Bogusław Buszewski to be included in the CEGSS were: Bulgaria, Bosnia and Herzegovina, Montenegro, North Macedonia and Greece. He has sent appropriate letters-invitations to the Chemical Societies of these countries and positive responses are expected. 

Table 1. CEGSS representatives of member country societies over the years

¹⁾Founders: Jože Marsel, Srečko Turina, Vratislav Švob, Branko Nikolin;

²⁾Honorary president: Dušan Berek; ³⁾President: Bogusław Buszewski;

⁴⁾Secretaries: 1^st Nikola Šegudović; 2^nd Dušan Berek; 3^rd Virginia Coman;

   Bold – current representative of member society, member of Steering Committee.

After the Corona-Virus pandemic, the statutory activities were resumed and the organization of the annual itinerant symposia was reactivated, thus continuing the CEGSS traditions. Irene Vovk, as the organizer of the 26^th ISSS, two times (2020 and 2021) postponed due to pandemic, performed this in June-July 2022, in Ljubljana, Slovenia, along with the 25^th HPTLC. Unfortunately, during this well-organized symposium, we all experienced great sadness and shock. The Honorary President of CEGSS, Dušan Berek, passed away here in Ljubljana. He was with us until the end. 

We started cooperation with the MDPI (Multidisciplinary Digital Publishing Institute) Publishing House, and in particular with the Separation Journal. There we made the joint decision (MDPI and CEGSS) to publish reports-histories on the separation sciences in individual member states, having as editors Bogusław Buszewski and Erwin Rosenberg ("CEGSS Yesterday, Today and Tomorrow"). So far, we have managed to publish four papers [4-7]. Unfortunately, in 2021, CEGSS suffered two greatest losses – Milan Hutta, Slovakia, and Pavel Jandera, Czechia, passed away. Their places were taken by Robert Góra, Slovakia, and Michal Holčapek, Czechia, who then was replaced by Petr Česla, Czechia. Also, Imre Klebovich, who retired, was replaced by Krisztiàn Horvàth, Hungary. In 2022, during the 26^th ISSS, at the CEGSS Steering Committee Meeting from June 30, 2022, these changes were unanimously accepted. 

In the year 2021, the Steering Committee of EuSSS decided to dissolve the society (Decision of the Register Court of Bayreuth; Bayern, from November 8, 2023). In 2009, at the request of Bogusław Buszewski, Hartmut Frank and Imre Molnár, the EuSSS established the European Prize, Tswett-Nernst [2], in memory of the two recognized scientists, Mikhail Semenovich Tswett, Russian-Italian biologist, inventor of column chromatography in the years 1903, and Walther Nernst, German physicist and chemist, laureate of the 1920 Nobel Prize in Chemistry. In this way, it was intended to appreciate at the European level all those who have made an indisputable contribution to the development of separation techniques and to significantly promote these techniques in the international community. Bogusław Buszewski, Poland, was appointed the chairman of the Tswett-Nernst Award Board and Václav Kašička, Czechia, became the secretary. In accordance with the regulations of this award, the statuette and diploma have been presented during the European Symposia on separation methods from the series of International Symposia on Chromatography, starting in 2010 at the 28^th ISC in Valencia, Spain, and International Symposia on Separation Sciences starting in 2022 at the 26^th ISSS in Ljubljana, Slovenia. As a result of a secret ballot, two winners are selected, one from Western Europe and one from Central, Eastern and Northern European countries. The winners are obliged to deliver a laureate plenary lecture. In 2022, by the decision of the last president of EuSSS, Didier Thiébaut, France, the rights and obligations to conduct the selection and the nomination of candidates were transferred to CEGSS. Starting in 2022 in Ljubljana, the Tswett-Nernst Prize is awarded during the Opening Ceremony of the ISSS symposia [3]. 

The organization of this series of symposia under the CEGSS auspices continues via Cluj-Napoca, Romania, (27^th ISSS 2023) to Messina, Italy, (28^th ISSS 2024) and to Belgrade, Serbia, (29^th ISSS 2025). 

Table 2. The ISSS symposia with places and names of particular organizers 

Reference: 

1. Bogusław Buszewski, What is the European Society for Separation Sciences (EuSSS), what is does, and what it plans to do? J. Sep. Sci., 2010, 33, 1361-1362  https://doi.org/10.1002/jssc.201090024

[2] European Society for Separation Science. Available on-line:

      https://www.mett.hu/eusss/index.php/2-uncategorised/16-nernsttswett-award (accessed on 10 August 2023) 

[3] Central European Group for Separation Sciences. Available on-line:

       https://cegss.ptchem.pl/ (accessed on 27 November 2023)

[4] Bogusław Buszewski, Separation sciences in Poland, Separations, 2022, 9, 50
      https://doi.org/10.3390/separations9020050

[5] Modest Gertsiuk, Chromatography in Ukraine: Development and Achievements,

Separations, 2022, 9, 114. https://doi.org/10.3390/separations9050114

[6] Danilo Corradini, Luigi Mondello, The 20-Year Jubilee of the Interdivisional Group of
      Separation Science of the Italian Chemical Society, Separations, 2022, 9, 123.

     https://doi.org/10.3390/separations9050123

[7] Šime Ukič, Danijela Ašperger, Tomislav Bolanča, A brief review of chromatography in
  Croatia, Separations, 2022, 9, 134. https://doi.org/10.3390/separations9060134

Separation Sciences in CEGSS counries