Open access

Introductory Chapter: An Introduction to Trace Elements

Written By

Martin Koller and Hosam M. Saleh

Published: 05 September 2018

DOI: 10.5772/intechopen.75010

From the Edited Volume

Trace Elements

Edited by Hosam El-Din M. Saleh and Eithar El-Adham

Chapter metrics overview

1,434 Chapter Downloads

View Full Metrics

1. Introduction

“Trace elements” are such building blocks of our planet and all living organisms, which, although occurring in rather modest concentration levels, are indispensable for a plethora of metabolic processes. Especially since the last decades, we observe enormously increasing efforts devoted by the scientific community to investigate, characterize and quantify trace elements. So-called “essential trace elements” are important constituents of human food, animal fodder, plant fertilizers, or cultivation media to form biotechnologically relevant microbes. Trace elements travel from the soil through the food chain, starting from phytoplankton until reaching our dinner tables; apart from food, drinking water is another important source for trace element uptake by all organisms. This makes trace elements interesting for diverse scientists such as analytical chemists, biochemists, geologists, physiologists, zoologists, and botanists [1].

In dependence on the scientific realm, different definitions for the terminus “trace elements” are found. An analytical chemist considers an element in a given sample with an average concentration of less than 100 ppm on an atomic counting basis or less than 100 μg/g on a mass basis, a “trace element”. In contrast, biochemists define “trace elements” as those elements, which, although present only in tiny amounts, are needed to maintain the physiological balance of an organism, often acting as cofactors in enzymatic reactions; this biochemical definition encompasses various heavy metals (iron, copper, nickel, vanadium, cobalt, manganese, molybdenum, chromium, and zinc), some nonmetals (boron and iodine), and certain metalloids (selenium, silicon, and arsenic). This definition implies a daily requirement for “essential trace elements” by humans in amounts between 50 μg and 18 mg/day [2]. To become susceptible toward metabolizing by animals and humans, some trace elements need to undergo transformation by microbes into complex bioavailable forms, as observed in the case of cobalt, which is utilized mainly as cyanocobalamin (vitamin B12) [3, 4]. Moreover, geologists define trace elements by concentrations not surmounting 1 pro mille of a rock or mineral. In addition, the term “trace element” is frequently used when analyzing the elemental composition of igneous rocks, hence those rocks formed by magma. In mineralogy, trace elements can substitute network-forming ions in mineral crystal structures; here, trace elements are not vital to a mineral’s defined composition and do not appear in the mineral’s chemical formula. However, as well known in the case of quartz, those metals occurring in trace quantities result in characteristic coloration of the minerals; for example, the substitution of silicon by iron in traces gives the quartz amethysts its famous purple coloration [5].

Keeping with trace elements playing a role in human metabolism, we find at least two of them as so-called “vital poisons” in the periodic system of elements, namely chromium and arsenic, well-known toxins, which, nevertheless, are essential for the functioning of our metabolism. Apart from the 14 undisputed essential trace elements mentioned in the above paragraphs, others, such as fluorine, strontium, or lithium, are suggested to also display biological functions in humans, which, although not clearly elucidated yet mechanistically, are evidenced by element deprivation effects in diverse metabolic studies [1, 6]. In addition, limited circumstantial evidence for certain benefits or biological function in mammals is reported in the case of the metals aluminum, rubidium, cadmium, germanium, tin, and lead, the so-called “ultra-trace elements” [7]. Only for prokaryotes, a physiological role of tungsten [8] and lanthanum [9] is generally accepted. What is not included in this list are all those elements which are present in significant amounts in our body, such as the four biological basic elements hydrogen, oxygen, carbon, and nitrogen and the macroelements sulfur, chlorine, phosphorus, magnesium, sodium, potassium, and calcium.


2. Determination of trace elements

However, trace elements are not only blessing but also curse by generating environmental and health-related concerns when exceeding certain concentration levels. In the context of environmentally sensitive trace elements, it is often not easy to draw a clear line between the desired concentration range of a trace element and the range in which it already exerts toxicity [10]. Aquatic environments, soil, organisms, food, fodder, energy carriers like coal, and airborne particles are targets, which are potentially contaminated with trace elements; this, in turn, provokes the need for modern, reliable, and fast tools for determination of trace element in diverse matrices. Although many problems caused by trace elements are already well managed in the meanwhile, constant vigilance in environmental exposure, application, and nutritional supply of trace elements still displays the conditio sine qua non, and calls for intensified research in trace element determination. For example, during mining, beneficiation, and combustion of coal as well as during metal mining and follow-up treatments, a total of about 26 trace elements, among them toxic heavy metals like mercury, need to be considered and quantified [6]. In the biological field, many plants are described to heavily accumulate trace elements from soil (metal “hyperaccumulator” plants); to understand these uptake mechanism and how the plants develop the required resistance factors needed to withstand the high concentration of trace elements, which often are highly toxic heavy metals, needs highly precise detection devices [11, 12]. The determination of type and concentration of trace elements in nutrition, body tissue and liquids, coal, water, soil, and so on is regarded as the first and most important step to follow the mechanisms controlling the dispersal and accumulation of trace elements. Element speciation in different media (water, soil, food, plants tissue, coal, biological matter, food and fodder, minerals, etc.) is pivotal to assess an element’s toxicity, bioavailability, environmental mobility, and biogeochemical performance. Classical methods for elemental analysis, such as gravimetric, titrimetric, calorimetric, and so on, do not sufficiently address the precision requirements when analyzing elements in trace concentrations. Therefore, new analytical techniques have been developed, which greatly simplified the quantitation of many trace elements and considerably extended their detection range. In this context, the development of reproducible and accurate techniques for trace element analysis in different media using spectroscopic instrumentation is continuously advanced. Here, inductively coupled plasma mass spectroscopy (ICP-MS) analysis of trace elements is of increasing importance; among the different ICP-MS techniques, modern developments like dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS) was successfully used to simultaneously determine 17 trace elements in blood samples [13]. Similar techniques encompass sector field inductively coupled plasma mass spectrometry (SF-ICP-MS), which was successfully used for determination of aluminum, beryllium, cadmium, cobalt, chromium, mercury, manganese, nickel, lead, and vanadium in urine, serum, blood, and cerebrospinal fluid [14]. Moreover, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) constitutes a quantitative microbeam technique for rapid and accurate determinations of trace element concentrations in the sub-ppm range in various target materials [15]. A classical method, atom absorption spectroscopy (AAS), is still widely used to quantify various trace elements [16, 17], for example, the well-known graphite furnace atomic absorption spectrometry, which was, inter alia, successfully used for trace element determination in fish samples [18]. Prior to AAS measurement, biological samples to be investigated for trace elements need to be solubilized by different ashing techniques; here, a multitude of methods exists, with the use of nitric acid for “wet ashing” often being the method of choice [19]. Decades ago, X-ray fluorescence analysis was recognized as a viable tool to determine trace elements in geological samples [2022]; in this context, a study reported by Leoni and Saitta in 1976 illustrated the viability of this technique to determine a total of 29 metals in rock and mineral samples in an astonishingly broad concentration range between 1 and 5000 ppm [20]. This AAS technique was later advanced to make it more custom-oriented and better applicable to different types of samples. Moreover, radiochemical trace element analysis is also widely used, mainly using radiochemical neutron activation analysis [23, 24]. By resorting to this method, trace elements were accurately determined in various samples, which are as diverse as human tissue [23], food products [16], and also in terrestrial, lunar, and meteoritic rock samples [24].


  1. 1. Prashanth L, Kattapagari KK, Chitturi RT, Baddam VRR, Prasad LK. A review on role of essential trace elements in health and disease. Journal of Dr. NTR University of Health Sciences. 2015;4(2):75
  2. 2. Mertz W. The essential trace elements. Science. 1981;213(4514):1332-1338
  3. 3. Fairweather-Tait SJ. Bioavailability of trace elements. Food Chemistry. 1992;43(3):213-217
  4. 4. Rickes EL, Brink NG, Koniuszy PR, Wood TR, Folkers K. Vitamin B12, a cobalt complex. Science (Washington). 1948;108(2797):134
  5. 5. Lameiras FS, Nunes EHM, Vasconcelos WL. Infrared and chemical characterization of natural amethysts and prasiolites colored by irradiation. Materials Research. 2009;12(3):315-320
  6. 6. Swaine DJ. Why trace elements are important. Fuel Processing Technology. 2000;65:21-33
  7. 7. Nielsen FH. Ultratrace minerals. In: Shils ME et al. USDA, ARS Source: Modern nutrition in health and disease. Baltimore: Williams & Wilkins; 1999. pp. 283-303
  8. 8. Andreesen JR, Makdessi K. Tungsten, the surprisingly positively acting heavy metal element for prokaryotes. Annals of the New York Academy of Sciences. 2008;1125(1):215-229
  9. 9. Campbell AK, Naseem R, Wann K, Holland IB, Matthews SB. Fermentation product butane 2, 3-diol induces Ca2+ transients in E. coli through activation of lanthanum-sensitive Ca2+ channels. Cell Calcium. 2007;41(2):97-106
  10. 10. Wang J, Liu G, Liu H, Lam PK. Multivariate statistical evaluation of dissolved trace elements and a water quality assessment in the middle reaches of Huaihe River, Anhui, China. Science of the Total Environment. 2017;583:421-431
  11. 11. Tangahu BV, Sheikh Abdullah SR, Basri H, Idris M, Anuar N, Mukhlisin M. A review on heavy metals (As, Pb, and Hg) uptake by plants through phytoremediation. International Journal of Chemical Engineering. 2011;2011. Article ID 939161
  12. 12. Chandra S, Gusain YS, Bhatt A. Metal hyperaccumulator plants and environmental pollution. In: Microbial Biotechnology in Environmental Monitoring and Cleanup. PA, USA: Hershey, IGI Global; 2018. pp. 305-317
  13. 13. D’Ilio S, Violante N, Di Gregorio M, Senofonte O, Petrucci F. Simultaneous quantification of 17 trace elements in blood by dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS) equipped with a high-efficiency sample introduction system. Analytica Chimica Acta. 2006;579(2):202-208
  14. 14. Bocca B, Alimonti A, Petrucci F, Violante N, Sancesario G, Forte G, Senofonte O. Quantification of trace elements by sector field inductively coupled plasma mass spectrometry in urine, serum, blood and cerebrospinal fluid of patients with Parkinson's disease. Spectrochimica Acta Part B: Atomic Spectroscopy. 2004;59(4):559-566
  15. 15. Liu Y, Hu Z, Gao S, Günther D, Xu J, Gao C, Chen H. In situ analysis of major and trace elements of anhydrous minerals by LA-ICP-MS without applying an internal standard. Chemical Geology. 2008;257(1-2):34-43
  16. 16. Bermudez GM, Jasan R, Plá R, Pignata ML. Heavy metal and trace element concentrations in wheat grains: Assessment of potential non-carcinogenic health hazard through their consumption. Journal of Hazardous Materials. 2011;193:264-271
  17. 17. Singh M, Yadav P, Garg VK, Sharma A, Singh B, Sharma H. Quantification of minerals and trace elements in raw caprine milk using flame atomic absorption spectrophotometry and flame photometry. Journal of Food Science and Technology. 2015;52(8):5299-5304
  18. 18. Tüzen M. Determination of heavy metals in fish samples of the middle Black Sea (Turkey) by graphite furnace atomic absorption spectrometry. Food Chemistry. 2003;80(1):119-123
  19. 19. Clegg MS, Keen CL, Lönnerdal B, Hurley LS. Influence of ashing techniques on the analysis of trace elements in animal tissue. Biological Trace Element Research. 1981;3(2):107-115
  20. 20. Leoni L, Saitta M. X-ray fluorescence analysis of 29 trace elements in rock and mineral standards. Rendiconti della Societa Italiana di Mineralogia e Petrologia. 1976;32(2):497-510
  21. 21. Rowe H, Hughes N, Robinson K. The quantification and application of handheld energy-dispersive X-ray fluorescence (ED-XRF) in mudrock chemostratigraphy and geochemistry. Chemical Geology. 2012;324:122-131
  22. 22. Margui E, Zawisza B, Sitko R. Trace and ultratrace analysis of liquid samples by X-ray fluorescence spectrometry. TrAC Trends in Analytical Chemistry. 2014;53:73-83
  23. 23. Lievens P, Versieck J, Cornelis R, Hoste J. The distribution of trace elements in normal human liver determined by semi-automated radiochemical neutron activation analysis. Journal of Radioanalytical and Nuclear Chemistry. 1977;37(1):483-496
  24. 24. Keays RR, Ganapathy R, Laul JC, Krähenbühl U, Morgan JW. The simultaneous determination of 20 trace elements in terrestrial, lunar and meteoritic material by radiochemical neutron activation analysis. Analytica Chimica Acta. 1974;72(1):1-29

Written By

Martin Koller and Hosam M. Saleh

Published: 05 September 2018