ORIGINAL ARTICLE High-frequency plasma in heritage photo decontamination Emil Ghiocel Ioanid & Dorina Rusu & Simona Dunca & Catalin Tanase Received: 2 February 2010 / Accepted: 30 March 2010 / Published online: 4 May 2010 # Springer-Verlag and the University of Milan 2010 Abstract This paper attempts to prove that high frequency (HF) plasma decontamination of photos is an efficient method. The color and gloss measurement, SEM and microbiological analysis were used to evidence the differ- ences which appear after plasma treatment. The HF cold air plasma experiments were carried out under the following working conditions: temperature 35–40°C, pressure 3.5×10 -1 –7×10 -1 mbar, frequency 13.5 MHz, over a period of 20 or 30 min. Microbiological analysis has proved the presence of the bacteria (genera: Bacillus, Sarcina, Micro- coccus, Clostridium) and fungi (genera: Alternaria, Clado- sporium, Aspergillus, Penicillium, Rhizopus). After the treatment, the total fungic decontamination point to the effect of HF plasma on genera Aspergillus, Cladosporium, Alternaria, Penicillium and Rhizopus. In bacterial decon- tamination, the inhibition of growth and strain development in the genera Sarcina and Micrococcus is noticeable after a plasma treatment of 20 and 30 min. The growth and strain development of Clostridium and Bacillus were inhibited only after 30 min treatment. The difference of color after the treatment indicates the cleaning effects of plasma. Keywords HF plasma . Disinfection . Bacteria . Fungi . Photos Introduction The preservation of cultural heritage artwork on organic support, which is very sensitive to the attack by micro- organisms, has become in recent decades a major preoccu- pation worldwide, gathering an increased number of specialists—restorers, conservators, physicists, biologists— dedicated to their mission of finding the best methods for the conservation and preservation of the cultural heritage objects. The virulent and long duration of attack by micro- organisms, especially bacteria and fungi, cause major degradations to the material support (Cappitelli et al. 2006). The degradation phenomenon constitutes an irreversible process of structural modifications affecting the matter and the object’ s value (Laguardia et al. 2005). Being very diverse from the point of view of structure and composi- tion, the objects degrade in their own specific way (Allsop et al. 2004). Photographs have a paper support, coated with a photosensitive substance (suspension of silver haloid in gelatin). Both paper made of cellulose and gelatins are natural organic compounds, which are very prone to attack by microorganisms generating chain degradation and consequently affecting the clarity of the images. Due to the biotical attack, a discoloration of the affected areas occurs and stains appear. Fungi cause structural and chromatic changes with consequences for the physico- mechanical behavior of the support. Although bacteria are found in smaller amounts on cultural heritage objects, as compared to fungi, they can also produce serious deterio- ration. Cellulosolitic bacteria decompose the cellulose, making it easily friable (Cappitelli and Sorlini 2005). E. G. Ioanid Romanian Academy “Petru Poni” Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, Ro.700487 Iasi, Romania D. Rusu (*) “Moldova” National Museum Complex, 1 Stefan cel Mare si Sfant, Ro. 700028 Iasi, Romania e-mail: dorina.emilia@yahoo.com S. Dunca : C. Tanase Faculty of Biology, “Alexandru Ioan Cuza” University, Iasi, Romania Ann Microbiol (2010) 60:355–361 DOI 10.1007/s13213-010-0051-2