Global Journal of Science Frontier Research, H: Environment & Earth Science, Volume 22 Issue 5

Validation of X-Ray Fluorescence Spectrometer Technique to Determine Heavy Metal Concentrations in Soil Samples Jessica Briffa ɲ , Renald Blundell ʍ , Emmanuel Sinagra ʌ & Joseph Grech ൿ 1 Global Journal of Science Frontier Research Volume XXII Issue V Year 2022 43 ( H ) Version I © 2022 Global Journals Abstract- Heavy metal soil pollution had increased in recent years and this has produced adverse effects to human wellbeing’s health by being uptaken in the food chain. A potential threat of heavy metal pollution was suspected at the Government Farm in G ħ ammieri. This is due to heavy traffic and fireworks causing concern to the farmers who cultivate fruit and vegetables in these fields. Soil sampling with an instrument that can give rapid results was needed to analyse the data and give the real-time in-situ mapping of heavy metal pollution in the soil. Comparison between an X-Ray Fluorescent (XRF) spectrometer and an Inductively Coupled Plasma – Mass Spectrometer (ICP-MS), both of which are conventional analytical techniques, was performed to measure the heavy metals in the soil by using laboratory and field work. This was performed to make sure that the XRF that was being used, would give accurate results before testing larger sample size. The XRF used was situated at the Department of Chemistry, at the University of Malta, whilst the ICP-MS was situated in Germany, at an accredited laboratory. Five samples were collected from around the whole field, where each sample was split into 2 identical batches. Heavy metal concentrations were determined using the XRF by sample cup method and results were validated using the ICP-MS using aqua regi digestion. To identify heavy metals without processing the sample, XRF is the preferred method due to direct analysis of the sample and less analysis time. XRF analysis produced quantitative results which correlated with high linearity when compared to the accredited ICP-MS data using the Spearman correlation coefficient (R2 = 0.811).A strong positive relationship close to 1 for arsenic (R2 = 0.646) copper (R2 = 0.888), cadmium (R2 = 0.202), lead (R2 =0.837), nickel (R2 = 0.513) and zinc (R2 = 0.699) was observed, whilst no relationship of R2=0 for chromium and mercury. When using the binomial test, all the ρ -values exceeded the 0.05 level of significance, signifying that the mean XRF score is comparable and positively related to the ICP-MS data. The analysis showed that the ICP-MS validated the XRF results for heavy metal soil measurements and implies . that XRF is quicker and reliable to use when measuring heavy metals in soil compared to traditional methods. heavy metals, soil, pollution, X-Ray fluorescent spectrometer, inductively coupled plasma – mass spectrometer, validation I. I ntroduction nvironmental pollutants and contaminants are chemicals found at a higher level than in any sector of the environment [1–4]. Industrialization has grown at an increased rate over the last few years. Thus, the request for utilization of the Earth’s natural resources has increased at a careless rate, which has aggravated the Earth’s problem regarding environmental pollution [5]. The environment has been critically polluted by several pollutants including inorganic ions, organometallic compounds, organic pollutants, radioactive isotopes, nanoparticles and gaseous pollutants .[2,4] Heavy metals are defined due to their high density or high atomic weight. Currently the word ‘heavy metal’ is used to explain metallic chemical elements together with metalloids that are toxic to both the environment and to humans. Some light metals and metalloids are toxic, such as including arsenic, aluminium and selenium, though not all heavy metals are toxic such as gold[6–9]. Heavy metals have been present in the Earth’s crust since the Earth’s formation. Heavy metal use has increased exponentially and has resulted in a surge of metallic substances in both aquatic and terrestrial environments[5]. Anthropogenic activity is the prime cause of heavy metal pollution, primarily due to mining of the metals, smelting, foundries, and other metal- based industries, leaching of metals from a variety of sources like landfills, excretion, waste dumps, livestock manure, automobiles, roadworks, and runoffs. The secondary cause of heavy metal pollution is agriculture including pesticides, fertilizers, insecticides, and more. Natural activity is another source which can increase heavy metal pollution including volcanic activity, metal evaporation from land and water, metal corrosion, soil erosion and geological weathering. Unintended pollution of heavy metals is also possible these include shipwrecks, oil spills and fires. Intended pollution can take the form of waste disposable like industrial effluents and sewage disposal, and intended application of E Keywords: . Author α: Faculty of Medicine and Surgery, University of Malta, Msida, MSD 2080, Malta. e-mail: jessica.mizzi.05@um.edu.mt Author σ : Faculty of Medicine and Surgery, University of Malta, Msida, MSD 2080, Malta; Faculty of Medicine and Surgery, Centre for Molecular Medicine, Biomedical Science Building, University of Malta, Msida, MSD 2080, Malta. * Correspondence author: e-mail: renaldblundell@gmail.com Author ρ Ѡ: Department of Chemistry, Faculty of Science, University of Malta, Msida, MSD 2080, Malta.