On behalf of the Scientific and Organizing Committees it is our great pleasure to invite researchers and practitioners of liquid and gaseous phase chromatography as well as capillary electromigration separation techniques to participate in the 21st International Symposium on Separation Sciences, which will be held on June 30 - July 3 2015 in Ljubljana, Slovenia. The program will include invited lectures, oral and poster presentations. The Exhibition will form an integral part of the Symposium and will be located in the venue halls. The symposium will cover new advances and challenges in all fields of separation sciences and hyphenated techniques thereof. It will provide an excellent opportunity for young scientists as well as renowned researches and industrial partners to exchange opinions, introduce ground-breaking ideas, and acquire new practical knowledge. Attractive and rich social programmes will create a perfect atmosphere to connect with old acquaintances and build long-lasting friendships that may blossom into fruitful joint adventures.