Investigation of correlation between histidine levels and metal concentrations of some hyperaccummulator plants grown around industrial area

SUMMARYINVESTİGATİON OF CORRELATİON BETWEEN HİSTİDİNE LEVELS AND METAL CONCENTRATİONS OF SOME HYPERACCUMMULATOR PLANTS GROWN AROUND İNDUSTRİAL AREASome plants can accumulate high concentrations of metals without damaging to the above-ground tissues such as leaves and twig. In these plants called as hyperacummulators, it was described that the absorption mechanisms of metals by plants can be interested to ligands such as systein, histidin and citrate. The aim of this study is to examine the correlation between metal and histidin in the plants reported as hyperaccumulator in literature. In the study, Pb, Cd, Ni and Cu concentrations and histidin levels of plants such as Pinus nigra L., Nerium oleander L., Robinia pseudoacacio L., Vitis vinifera L., Morus L., Angustifolia L., Juglans regia L., Platanus L., Populus nigra L. Cupressus arizonica L., collected from industrial areas in Gaziantep and Bursa and control sites were determined by ICP-MS and HPLC-MS, respectively. From the optimization studies for histidine determination by HPLC-MS, optimum conditions were found to be the flow rate: 0.2 mL/min, injection volume:15 ?L, column temperature:20 ºC and fragmentor potential:70 V. From the optimization studies for extraction of the plant samples, optimum conditions was found to be water as the best solvent, the optimum extraction period: 30 min and the optimum ratio of solvent/solid: 20/1 (v/w). To determine the reliability of results, standard additions metod was applied. From the results, it was found that Pb concentrations between 0.5-375 mg/kg, Cd concentrations between 0.011-0.605 mg/kg, Cu concentrations between 2.6-11.7 mg/kg and Ni concentrations between 0.6-9.9. Concentrations of histidine in plant samples were found to be in range of 0.9-32.7 mg/kg. When the obtained results were evaluated statistically, the correlation between Ni and histidine (p<0.05) in mulberry plant was found to be meaningful statistically while correlation between histidine and metals including Pb, Cd and Cu for the same plant species was meaningless. Similarly, correlation between histidine and the Ni and Cd in Robinia pseudoacacio L. (p<0.05) and Pb in Cupressus arizonica L. (p<0.05) were found to be meaningful statistically.Key Words: Histidine, HPLC-MS, lead, cadmium, nickel, cupper, hyperaccumulator plant.