Machine learning approaches for simultaneous spectrophotometric determination of heavy metal ions in water samples



  • Nguyen Thi Lan Anh (Corresponding Author) Institute of Chemistry and Materials, Academy of Military Science and Technology
  • Bui Phuong Thi Faculty of Chemistry, VNU University of Science
  • Do Thi Nhat Quyen Faculty of Chemistry, VNU University of Science
  • Vu Quynh Thu Faculty of Chemistry, VNU University of Science
  • Nguyen Thu Huong Institute of Chemistry and Materials, Academy of Military Science and Technology
  • Khuat Hoang Binh Institute of Chemistry and Materials, Academy of Military Science and Technology
  • Khong Manh Hung Institute of Chemistry and Materials, Academy of Military Science and Technology
  • Nguyen Chi Thanh Institute of Information Technology, Academy of Military Science and Technology
  • Ta Thi Thao Faculty of Chemistry, VNU University of Science



Simultaneous determination; Heavy metal; ANN method; 4-(2-pyridylazo) resorcinol.


In this study, the simultaneous determination of Co, Cd, Ni, Cu, and Pb was carried out as a color complex with 4-(2-pyridylazo) resorcinol in an aqueous solution under the assesting of machine learning. A partial least-squares multivariate linear regression and artificial neuron network for the analysis of mixtures of metals were developed. MATLAB is a powerful software machine learning program that was used to support matrix calculations and displays. The benefit of MATLAB in the construction of the machine learning model allows the development of a rapid and highly effective analysis of multiple components in the mixtures without separation and enrichment. For individual determinations, the working ranges were discovered as the important information for choosing the initial concentration of each heavy metal in a mixture, r. The results of analysis of Ni2+, Pb2+, and Cd2+ by two methods Partial Least Squares - PLS and Artificial Neural Networks - ANN are sensitive and accurate for simultaneous determination of the concentration of these ions in the synthesis mixture with a high regression coefficient of 0.993, respectively, 0.997, 0.997 for Ni2+, Pb2+ and Cd2+. As for Cu2+ and Co2+, the accuracy is higher when using the ANN method.


[1]. Duruibe, J. O., Ogwuegbu, M. O. C., Egwurugwu, J. N., “Heavy metal pollution and human biotoxic effects”, International Journal of Physical Sciences, Vol. 2 (5), pp.112-118, (2007).

[2]. Muhammad Aqeel Ashraf et al., “Speciation of heavy metals in the surface waters of a former tin mining catchment”, Chemical Speciation & Bioavailability, 24, pp.1-12, (2015). DOI:

[3]. Herawati N, Suzuki S, Hayashi K, Rivai If, Koyoma H. Cadmium, “Copper and zinc levels in rice and soil of japan, indonesia and china by soil type”, Bulletin of Environmental Contamination and Toxicology, 64, pp.33-39, (2000). DOI:

[4]. He Zl, Yang Xe, Stoffella Pj., “Trace elements in agroecosystems and impacts on the environment”, Journal of Trace Elements in Medicine and Biology, 19(2–3), pp.125-140, (2005). DOI:

[5]. Korbas, M.; O’donoghue, J.L.; Watson, G.E.; Pickering, I.J.; Singh, S.P.; Myers, G.J.; Clarkson, T.W.; George, G.N., “The chemical nature of mercury in human brain following poisoning or environmental exposure”, Acs Chem. Neurosci., 1, pp.810–818, (2010). DOI:

[6]. Zhou, Y.; Vaidya, V.S.; Brown, R.P.; Zhang, J.; Rosenzweig, B.A.; Thompson, K.L.; Miller, T.J.; Bonventre, J.V.; Goering, P.L., “Comparison of kidney injury molecule-1 and other nephrotoxicity biomarkers in urine and kidney following acute exposure to gentamicin, mercury, and chromium”, Toxicol. Sci., 101, pp.159–170, (2007). DOI:

[7]. Strong FC, Martin NJ, “Rapid determination of zinc and iron in food by flow – injection analysis with flame atomic – absorption spectrophotometry and slurry nebulization”, Talanta 7:11-718, (1990).

[8]. Šmirjákova, S., Ondrašovičová, O., Kašková, A., Laktičová, “The effect of cadmium and lead pollution on human and animal healths”, 49, 3: — Supplementum, S31—S32, (2005).

[9]. Davidson, C. M. “Methods for the Determination of Heavy Metals and Metalloids in Soils”. Heavy Metals in Soils, pp.97–140, (2012).

[10]. Khamms AA, Al-Ayash AS, Jasin F. “Indirect electrothermal atomization AAS Spectrometric determination of drugs, desferrioxamine in some pharmaceutical preparations using Vanadium (V) as a mediatory element elestial”. J. Anal. Chem. 3, pp.257- 269, (2009).

[11]. Davidson, C. M. “Methods for the determination of heavy metals and metalloids in soils”. Heavy metals in soils: Trace metals and metalloids in soils and their bioavailability, 97-140, (2013). DOI:

[12]. Makedonski, L., Peycheva, K., & Stancheva, M. “Determination of heavy metals in selected black sea fish species”. Food Control, 72, 313-318, (2017). DOI:

[13]. Ugulu, I. “Determination of heavy metal accumulation in plant samples by spectrometric techniques in Turkey”. Applied Spectroscopy Reviews, 50(2), 113-151, (2015). DOI:

[14]. Adebayo, I. A. “Determination of heavy metals in water, fish and sediment from Ureje water reservoir”. Journal of Environmental & Analytical Toxicology, 7(4), 1-4, (2017). DOI:

[15]. Okoye COB, “Spectroscopic methods of analysis.Undergraduate Analytical Chemistry”, Jolyn Publishers, Nsukka, pp. 98-119, (2005).

[16]. Soomro R, Jamahiddin MA, Menpou N, Khan H, “A simple and selective spectrophotometric method for the determination of trace Gold on real Environmental”, Biological, Geological and Soil samples using Bis, (Salicylaldehyde) Orthphenyldiamine. J. Anal. Chem. Insights 3, pp.75-90, (2009). DOI:

[17]. Zeiner, M., Rezic, I., & Steffan, I. “Analytical methods for the determination of heavy metals in the textile industry”. Kem. Ind, 56(11), 587-59, (2007).

[18]. Ahmed, A., Singh, A., Padha, B., Sundramoorthy, A. K., Tomar, A., & Arya, S. “UV–vis spectroscopic method for detection and removal of heavy metal ions in water using Ag doped ZnO nanoparticles”. Chemosphere, 303, 135208, (2022). DOI:

[19]. Echioda, S., Ogunieye, A. O., Salisu, S., Abdulrasheed, A. A., Chindo, I. Y., & Kolo, A. M. “UV-Vis spectrophotometric determination of selected heavy metals (Pb, Cr, Cd and As) in environmental, water and biological samples with synthesized glutaraldehyde phenyl hydrazone as the chromogenic reagent”. European Journal of Advanced Chemistry Research, 2(3), 1-5, (2021). DOI:

[20]. Nai-Liang H, Hong-wen G, Biao ZI, Guo-Qing Z. “Simultaneous Determinations of Cobalt and Nickel in waste water with 2.- Hydroxyl – 5 – benzene azoformoamithiozone by spectral correction Technique”. J. Chin. Chem. Soc. 52, pp.1145-1152, (2005). DOI:

[21]. Śliwińska, A., Smolinski, A., & Kucharski, P. “Simultaneous analysis of heavy metal concentration in soil samples”. Applied Sciences, 9(21), 4705, (2019). DOI:

[22]. Ding, Y., Xia, G., Ji, H., & Xiong, X. “Accurate quantitative determination of heavy metals in oily soil by laser induced breakdown spectroscopy (LIBS) combined with interval partial least squares (IPLS)”. Analytical methods, 11(29), 3657-3664, (2019). DOI:

[23]. Ucun Ozel, H., Gemici, B. T., Gemici, E., Ozel, H. B., Cetin, M., & Sevik, H. “Application of artificial neural networks to predict the heavy metal contamination in the Bartin River”. Environmental Science and Pollution Research, 27, 42495-42512, (2020). DOI:

[24]. Alizamir, M., & Sobhanardakani, S. “Forecasting of heavy metals concentration in groundwater resources of Asadabad plain using artificial neural network approach”. Journal of Advances in Environmental Health Research, 4(2), 68-77, (2016).

[25]. Pyo, J., Hong, S. M., Kwon, Y. S., Kim, M. S., & Cho, K. H. “Estimation of heavy metals using deep neural network with visible and infrared spectroscopy of soil”. Science of the Total Environment, 741, 140162, (2020). DOI:

[26]. Liu, L., Huan, H., Zhang, L., Zhao, B., & Shao, X. “Determination of heavy metal soil contaminants based on photoacoustic spectroscopy”. International Journal of Thermophysics, 41, 1-10, (2020). DOI:

[27]. Emiko Ohyoshi, “Relative stabilities of metal complexes of 4-(2-pyridylazo) resorcinol and 4-(2-thiazolylazo) resorcinol”, Polyhedron, Vol. 5, No. 6, pp.1165-1170, (1985). DOI:

[28]. J. Ghasemi Et Al., “Spectrophotometric studies on the protonation and nickel complexation equilibria of 4-(2-pyridylazo) resorcinol using global analysis in aqueous solution”, J. Braz. Chem. Soc., Vol. 18, No. 2, pp.267-272, (2007). DOI:




How to Cite

Nguyễn, L. A., Bui Phuong Thi, Do Thi Nhat Quyen, Vu Quynh Thu, Nguyen Thu Huong, Khuat Hoang Binh, Khong Manh Hung, Nguyen Chi Thanh, and Ta Thi Thao. “Machine Learning Approaches for Simultaneous Spectrophotometric Determination of Heavy Metal Ions in Water Samples”. Journal of Military Science and Technology, vol. 95, no. 95, May 2024, pp. 47-54, doi:10.54939/1859-1043.j.mst.95.2024.47-54.



Research Articles


Most read articles by the same author(s)