Sample Preparation and Analytical Techniques in the Determination of Trace Elements in Food: A Review

Abstract

Every human being needs around 20 essential elements to maintain proper physiological processes. However, trace elements are classified as beneficial, essential, or toxic for living organisms. Some trace elements are considered essential elements for the human body in adequate quantities (dietary reference intakes, DRIs), while others have undetermined biological functions and are considered undesirable substances or contaminants. Pollution with trace elements is becoming a great concern since they can affect biological functions or accumulate in organs, causing adverse effects and illnesses such as cancer. These pollutants are being discarded in our soils, waters, and the food supply chain due to several anthropogenic factors. This review mainly aims to provide a clear overview of the commonly used methods and techniques in the trace element analysis of food from sample preparations, namely, ashing techniques, separation/extraction methods, and analytical techniques. Ashing is the first step in trace element analysis. Dry ashing or wet digestion using strong acids at high pressure in closed vessels are used to eliminate the organic matter. Separation and pre-concentration of elements is usually needed before proceeding with the analytical techniques to eliminate the interferences and ameliorate the detection limits.

Atomic spectrometry update – a review of advances in environmental analysis

“…Three reviews covered techniques for elemental analysis of plants . El Hosry et al 95 (177 references) provided an accessible introduction to FAAS, ICP-AES, ICP-MS and XRFS, together with guidance on the selection of techniques for the analysis of plant-based foods. Ibourki et al 96 (224 references) discussed similar topics but also featured LIBS and NAA.…”

Atomic spectrometry update: review of advances in the analysis of clinical and biological materials, foods and beverages

“…The review by El Hosry et al 7 covered both sample preparation and analytical techniques for the determination of trace elements in food. The paper includes a discussion of the criticalities of the initial steps required to produce a representative laboratory sample (Section 3.1), as well as an overview of techniques for sample pre-treatment, e.g.…”

“…Several analytical techniques, as well as methods of sample preparation, can be applied to the determination of trace elements in foods. The review by El Hosry et al 7 includes an overview of commonly used techniques for sample preparation prior to the determination of trace elements in food . After covering the initial steps of sample preparation, such as cleaning, cutting and grinding, to produce a representative laboratory sample suitable for further processing, they considered the advantages, drawbacks and criticalities of subsequent treatments.…”

“…Speciation was not mentioned. Much of the same ground was covered by El Hosry et al in a review 7 of 177 publications that included a table of concentration ranges for As, Cd, Cr, Hg and Pb in selected foods in different countries of the world, as well as sections devoted to the bio- and environmental chemistry of each element. They noted that MAD was widely used.…”

Assessment of the Concentration of 51 Elements in the Liver and in Various Parts of the Human Brain—Profiling of the Mineral Status

“…Agilent 8900 ICP-MS Triple Quad (Agilent, Santa Clara, CA, USA) was employed for analysis of 51 elements ( 9 Be, 23 Na, 24 Mg, 27 Al, 31 P, 39 K, 44 Ca, 47 Ti, 51 V, 52 Cr, 55 Mn, 56 Fe, 59 Co, 60 Ni, 63 Cu, 66 Zn, 71 Ga, 85 Rb, 88 Sr, 90 Zr, 75 As, 75→91 As, 78 Se, 78→94 Se, 95 Mo, 105 Pd, 107 Ag, 111 Cd, 118 Sn, 121 Sb, 133 Cs, 137 Ba, 139 La, cerium 140 Ce, praseodymium 141 Pr, neodymium 146 Nd, samarium 147 Sm, europium 153 Eu, 157 Gd, terbium 159 Tb, dysprosium 163 Dy, holmium 165 Ho, erbium 166 Er, thulium 169 Tm, ytterbium 172 Yb, 178 Hf, 195 Pt, 201 Hg, 202 Hg, 205 Tl, 208 Pb, 209 Bi, 232 Th, 238 U). Most elements were analyzed in He mode (5.5 mL min −1 helium flow).…”