Document Type : Original Research Article


1 Department of Chemistry, faculty arts & science Alabyar, University of Benghazi, Libya

2 Department of Chemistry, Faculty of Science, University of Benghazi, Benghazi, Libya


This article presents a new approach to measure the concentrations of lead and cadmium in soil marine samples. The technique involves a two-step process: first, the samples are pre-concentrated using liquid-liquid extraction, and then atomic fluorescence spectrometry is used for analysis. In this process, dithizone is used as the chelating agent. During the procedure, a complex is formed between lead and cadmium with dithizone. The researchers also investigated important factors that may affect the efficiency of the extraction, such as pH of the sample and shaking duration.
The results demonstrated that the extraction process yielded optimal results within a pH range of 7 to 9, and the ideal duration of shaking was between 10 to 30 minutes. Through stoichiometry analysis, it was determined that the most probable structure of the extracted ion pair complex consisted of one metal ion bonded to two ligand molecules (1M+2:2HDZ-). The influence of organic solvents on the extraction process showed that the distribution ratio (D) for extraction increased with a decrease in dielectric constant. Particularly, carbon tetrachloride demonstrated a higher distribution ratio (D), possibly due to its lower dielectric constant, which aids in the disruption of hydration shell around metal cations (Cd and Pb), allowing for enhanced coordination between the ligand molecules and metal cations. A previously described method for analyzing Cd and Pb in marine soil was adapted for this study. 

Graphical Abstract

Evaluation of Cadmium (II) and Lead (II) in marine soil in Benghazi city using Atomic Absorption Spectroscopy


Main Subjects


    1. Qi X, Xu X, Zhong C, Jiang T, Wei W, Song X. Removal of cadmium and lead from contaminated soils using sophorolipids from fermentation culture of Starmerella bombicola CGMCC 1576 fermentation, International journal of environmental research and public health; 2018 Nov; 15(11):2334.
    2. Briffa J, Sinagra E, Blundell R. Heavy metal pollution in the environment and their toxicological effects on humans, Heliyon; 2020 Sep 1; 6(9).
    3. Sturgeon RE, Berman SS, Desaulniers JA, Mykytiuk AP, McLaren JW, Russell DS. Comparison of methods for the determination of trace elements in seawater, Analytical Chemistry; 1980 Sep 1; 52(11):1585-8.
    4. Danielsson LG, Magnusson B, Westerlund S. An improved metal extraction procedure for the determination of trace metals in sea water by atomic absorption spectrometry with electrothermal atomization, Analytica chimica acta; 1978 May 1; 98(1):47-57.
    5. Sugimae A. Determination of trace elements in sea water by inductively-coupled plasma emission spectrometry, Analytica Chimica Acta; 1980 Dec 1; 121:331-6.
    6. Smith Jr RG, Windom HL. A solvent extraction technique for determining nanogram per liter concentrations of cadmium, copper, nickel and zinc in sea water, Analytica Chimica Acta; 1980 Jan 1; 113(1):39-46.
    7. Kiwan AM, Wanas GA, Hassan FM. Studies of 1, 5-Bis (3, 4, 5-trimethoxyphenyl)-and 1, 5-Bis (2-methoxy-4-methylphenyl)-3-mercaptoformazans and Their Reactions with Metal Ions, Analytical sciences; 1993 Oct; 9(5):687-90.
    8. Purnamawaty E, Amimoto T, Imura H, Usui Y, Ohashi K. Extraction equilibrium of Molybdenum (VI) with several alkylated 8-Quinolinol derivatives, Analytical sciences; 1994 Oct 10; 10(5):749-53.
    9. Itoh Y, Kawamoto H, Akaiwa H. Preconcentration of cobalt (II) using synergistic extraction with dithizone and tributylphosphine oxide, Analytical sciences; 1986; 2(1):43-6.
    10. Akaiwa H, Kawamoto H, Tanaka T. Rate-promoting effect of pyridine bases on the extraction of cobalt (II) and nickel (II) with dithizone, Analytical sciences; 1987 Apr; 3(2):113-6.
    11. Larson SB, Dalley NK. Structure of the potassium thiocyanate complex of 3, 6, 9, 12, 15-pentaoxa-21-azabicyclo [15.3. 1] henicosa-1 (21), 17, 19-triene-2, 16-dione, Acta Crystallographica Section B: Structural Crystallography and Crystal Chemistry; 1980 May 15; 36(5):1201-4.
    12. Oliveira ED. Sample preparation for atomic spectroscopy: evolution and future trends, Journal of the Brazilian Chemical Society; 2003; 14:174-82.
    13. Hoenig M, de Kersabiec AM. Sample preparation steps for analysis by atomic spectroscopy methods: present status, Spectrochimica Acta Part B: Atomic Spectroscopy; 1996 Sep 1; 51(11):1297-307.
    14. Cal-Prieto MJ, Felipe-Sotelo M, Carlosena A, Andrade JM, López-Mahıa P, Muniategui S, Prada D. Slurry sampling for direct analysis of solid materials by electrothermal atomic absorption spectrometry (ETAAS). A literature review from 1990 to 2000, Talanta; 2002 Jan 4; 56(1):1-51.
    15. Bader NR. Sample preparation for flame atomic absorption spectroscopy: an overview, Rasayan Journal of Chemistry; 2011; 4(1):49-55.
    16. Kratochvil B, Taylor JK. Sampling for chemical analysis, Analytical Chemistry; 1981 Jul 1; 53(8):924A-38A.
    17. Fritz JS, Schenk GH, Quantitative analytical chemistry, Allyn, Bacon Inc, Boston Massachusetts; 1979.
    18. Harris DC. Quantitative Chemical Analysis, 845-846, 863-864.
    19. Anal., 190, 118 (1878).
    20. Anal., 212, 316 (1882).
    21. Iwantscheff G, Fischer H. Das Dithizon und seine Anwendung in der Mikro-und Spurenanalyse. (No Title). 1958.
    22. Sandell, E. Colorimetric Determination of traces of Metals, Imerscience Publishers, Inc., New York, N. Y., (1959).
    23. Yavuz Ö, Guzel R, Aydin F, Tegin I, Ziyadanogullari R. Removal of Cadmium and Lead from Aqueous Solution by Calcite, Polish journal of environmental studies; 2007 May 1; 16(3).
    24. Micheal, T. Greenberg, A., Hoak, R .Standard Methods for the Examination of Water and Wastewater. Washington: American Public Health Association, American Water works Association & Water Pollution Control Federation. (1976).
    25. Donnelly KC, Brown KW, Thomas JC. Mutagenic potential of municipal sewage sludge amended soils. Water, Air, and Soil Pollution. 1989 Dec;48:435-49.
    26. Irving HM, Kiwan AM, Rupainwar DC, Sahota SS. Studies with dithizone: Part XXV. The deterioration of stock solutions and the identification of two oxidation products, Analytica Chimica Acta; 1971 Sep 1; 56(2):205-20.
    27. Mawby A, Irving HM. The crystal structure of primary zinc (II) dithizonate, Journal of Inorganic and Nuclear Chemistry; 1972 Jan 1; 34(1):109-15.
    28. Daoji L, Daler D. Ocean pollution from land-based sources: East China Sea, China, Ambio; 2004 Feb 1; 107-13.




    Mohammed Y. gargoghil, Fatma A. Rajab, Najwa H. Ansir, Evaluation of Cadmium (II) and Lead (II) in Marine Soil in Benghazi City Using Atomic Absorption Spectroscopy, Ad. J. Chem. B, 5 (2023) 320-329.

    DOI: 10.48309/ajcb.2023.407758.1180