http://www.revistadechimie.ro REV.CHIM.(Bucharest)♦70♦ No. 3 ♦2019 1080 From the Complex Process of Gold Ions Recovery in New Antimicrobial Product MARIA MIHAILESCU 1 , PETRU NEGREA 1 *, NARCIS DUTEANU 1 , ADINA NEGREA 1 , MIHAELA CIOPEC 1 , VASILE GHERMAN 1 *, RAMONA BUZATU 2 , MARILENA MOTOC 2 1 Politehnica University of Timisoara, Faculty of Industrial Chemistry and Environmental Engineering, 2 Victoriei Sq., 300006 Timisoara, Romania 2 Victor Babes University of Medicine and Pharmacy Timisoara, 2 Eftimie Murgu Sq., 300041, Timisoara, Romania Production of new antibacterial materials is really important due to high resistance bacteria at classical antibiotics. In present study,using the adsorption process of gold ions loaded onto Amberlite XAD7-L-glutamic acid, antibacterial material wasproduced.The antibacterial activity of produced material was studied. In order to test this activity, frstly it was necessary to know the microbiological behaviour of Au(III), by running several toxicity tests . Synthesized material show good antibacterial activity against a broad spectrum of bacteria collected form BegaRiver. These studies were performed in order to find a new application of such materials as paints used as antibacterial agents in hospitals and for domestic use. Keywords:Amberlite XAD7, antibacterial activities, gold, L-glutamic acid, toxicity Gold extraction from different minerals is possible by using hydrometallurgical processes, although the traditional method is the cyanide extraction. Starting with the beginning of the XX century this method was unanimous accepted around the world[1]. Main disadvantage of such process is represented by higher toxicity of the cyanide, which can pollute the groundwater as a consequence of accidental leaking, representing a real threat to human health. Because of that it is really important to develop and implement new and clean technologies for gold production and recovery, like adsorption, thus avoiding the appearance of other residual contaminants. Materials with adsorbent properties used for gold recovery can be: active carbon particles [2], mesoporous adsorbents[3],chitosan, or chemical modified oxides [4,5]. Field of materials engineering should consider aspects of antibacterial and bactericidal properties in the design of new materials for advanced biomaterial systems with medical applications [6]. Last decades brought a larger use of gold in fields like electronic or medical devices. Gold usage has a long history, for example it was used as medicine (Chrysitherapy)since antiquity. Gold has been used to treat diseases such as small pox, syphilis, skin ulcers and measles [7,8]. Its usage as medicine shows several benefits such as: stress and anxiety reduction, depression recovery, increased determination, increase of the intelligence coefficient until 20 units on Stanford-Binet scale, toning weakened organs, consequently improving the well-being of subjects. Since 70’s gold was included into the category of modern drugs used to ensure a good health of the joints especially in serious diseases such as rheumatoid arthritis [9]. At physical level gold is acting over the endocrine system and especially over the pituitary gland. Materials containing gold particles can be used in medical imaging and as well as into the cancer therapy [10]. Also, an enhanced and harmonized function of the endocrine gland which balancing secretion of different peptides - hormones, neurotransmitters - having a reviving and rejuvenating role was observed. Some tests proved that gold drugs strengthen the bone system and improve the sexual * email: petru.negrea@upt.ro; ghermanvasile2000@yahoo.com; function. On cardiac level - was noticed that gold present a good efficiency into the equilibration of cardiac function, myocardial toning, adjusting heart rate, adjusting blood pressure, sanguine flow, elimination of cardiomyopathy and heart failure[11-13].A big number of experimental studies proved that gold particles and gold ionic form present good antimicrobial and antibacterial effects[14]. It was proved that the cationic form of gold presents a moderate toxicity and the anionic form present zero toxicity[15]. Gold is probably the oldest metal used as delivery vehicle for gene therapy, and one of the most advanced agents in all drug pharmacopoeias, its administration to humans being both deliberate and unintentional. The widest clinical application of gold (in rheumatoid arthritis) derives from a premise that was totally flawed. It has been used clinically to perform immune suppression but has caused toxicity. Despite the many known advantages of gold applications into different various economic areas, there is a serious concern about the toxicity of such materials on living organisms. The toxicity of gold, unlike most drugs, is not predictably related to the levels it achieves in body tissues.As a result, gold pharmacology and toxicology is remarkably complex. Recent laboratory findings on gold metabolism have highlighted the important metabolic differences between the three oxidation states (0, I and III). When placed in the context of a wealth of clinical experience, these findings provide useful information on its toxicology and mechanisms that involve the seemingly paradoxical behaviour of gold [16]. Toxic effect of gold materials onto the living organisms depends on the availability of materials. Bioavailability of gold particles is determined by adsorption, which depends on the particle size and superficial load. If materials exhibit a good bioavailability, they can also induce teratogenic effects [15]. In most cases, the toxicity tests of different materials are made using in vivo test onthe cells cultures. Thus, the goal of this study was to determine the minimum concentration at which gold ions become toxic for bacterial cultures. Based on these results same amount of gold was adsorbed onto the surface of Amberlite XAD7