Spectroscopic investigation of toxic heavy metals in environmental samples from coastal area of Vlora in Albania using XRFS, AAS, LIBS

This interdisciplinary and complex work represents the spectroscopic investigation performed on environmental samples by EDXRF using Mo secondary target excitation, AAS, and LIBS. In a wide tourist area of interests for its potential and its geographical position including sea, lagoons and river, toxic heavy metals and other metals As, Cr, Cd, Hg, Ni, Pb, Mn, Fe, Zn, Sr, Rb, Ti, Ca, Y, Zr, in marine sediment sea water, suspended particulate matter and Mediterranean mussels were analyzed. As, Cr, Cd, Hg, Pb, Ni, are the most representative elements regarding the environmental risk associated with their massive use, their toxicity, and their wide dissemination. Different spectroscopic methods AAS (CV/AAS, GFAAS, FAAS) were used to analyze Hg, Cd and the other toxic heavy metals in different environmental samples including mussels as bioindicator in the coastal area under the study. Some qualitative multielemental analysis were performed using LIBS (Laser Induced Breakdown Spectroscopy) an effective multitlemental technique, obtaining good results for the presence of toxic heavy metals in the marine sediments under the study. The water samples analysis were performed using two analytical methods: a) EDXRF (multielemental analysis) for the determination of heavy metal ions by precipitation with APDC combined with XRF; b) AAS (Atomic Absorption Spectrometry), Flame & Graphite furnace AAS. The elemental analysis for the determination of Hg in sea water and sediments and mussels were obtained by CV/AAS (Cold Vapor Atomic Absorption Spectroscopy) The detailed analysis of mixed fractions and of the fractions of sediments according to the grain size or granulometric layer obtained by multielemental, reliable, fast, nondestructive and low cost EDXRFS method confirms the right quantity of toxic heavy metals under investigation in some areas of public domain. In particular, we detected large contents of Cr, As, Ni or other element in few selected stations, while Cr resulted to be much higher than any value obtained in previous studies by destructive methods. The intensities of analyte line were determined by the program AXIL and the calculation of the concentration was realized by program COREX which uses backscatter peaks and fundamental parameters. 20 reference materials are used for quality control of the results. The concentration of toxic heavy metals in marine sediments obtained by XRFS and AAS methods were compared with the Sediment Quality Guidelines (SQGs) values in order to evaluate the ecotoxicological risk and to predict biological effects of heavy metals. Our work suggests that XRFS analysis is a good candidate (compared with other analytical methods) to assess the right content of total heavy metals in marine sediments, which suggest us to undertake subsequently the following step determining the bioavailable part and remobilization potential.