[1] Zickerick was a research associate at the Friedrich Ebert Stiftung in Lagos, Nigeria.

[1] Zickerick began his diplomatic career in 1980, working for the German Foreign Office as an attaché.

[1] In the late 1990s he worked in Germany, focusing on the federal government's programs for relationships with Eastern Europe and implementing the Stability and Growth Pact.

[1] In 2000 Zickerick was appointed as the German ambassador to Moldova, taking up residence at the Embassy of Germany, Chișinău.

[1][4] While serving as director general, Zickerick oversaw an agreement to deter tax evasion and abolish double income taxation and capital gains.

[6] At his farewell celebration, he presented the German-Taiwanese Friendship Medal to Charlotte Han, the honorary president of the Sino-German Cultural and Economic Association, to Angelika Chen, a businesswoman from Southern Taiwan, and to Der-Tsai Lee, president of National Chung Hsing University.