Determination Of Trace Elements Research Articles

Trophic dynamics of methylmercury and trace elements in a remote Amazonian Lake

Information on pollutant trophodynamics can be crucial for public health, as contaminated food consumption may lead to deleterious effects. This study was performed in Puruzinho Lake, a remote body of water in the Brazilian Amazon from which a riparian human population obtains an important part of its animal protein intake. Samples from 92 individuals, comprising 13 species and four trophic guilds (iliophagous, planktivorous, omnivorous, and piscivorous fish) were analysed for the determination of trace elements (Fe, Cr, Mn, Ni, Zn, Ca, Sr, Cd, Sn, Tl and Pb) and methylmercury concentrations. Samples from the same individuals had already been analysed for stable isotope (SI) measurements (δ13C and δ15N) in a previous investigation and the SI data have been statistically treated with those generated in this study for the evaluation of trophic dynamics of contaminants. Methylmercury was the only analyte that biomagnified, presenting TMF values of 4.65 and 4.55 for total and resident ichthyofauna, respectively. Trace elements presented either trophic dilution or independence from the trophic position, constituting a behaviour that was coherent with that found in the scientific literature. The similarity between Ni behaviour through the trophic web to that of essential elements contributes to the discussion on the essentiality of this metal to fish. Considering the Non-cancer Risk Assessment, the calculated Target Hazard Quotient (THQ) values were higher than 1.0 for all analysed individuals for methylmercury, as well as for only one individual for nickel. No other analyte rendered THQ values higher than 1.0.

Determination of trace, minor and major elements of medicinal plants used for common diseases through PIXE method

Determination of trace, minor and major elements of medicinal plants used for common diseases through PIXE method

Investigation and elimination of surfactant-induced interferences in anodic stripping voltammetry for the determination of trace amounts of cadmium

This article aims to investigate in detail to what extent surfactants affect the determination of cadmium by anodic stripping voltammetry. In recent years, the production and use of surfactants have been steadily increasing, so that their concentration in environmental water samples is rising. At the same time, it is known that organic compounds, such as surfactants, often hinder the voltammetric determination of trace elements by stripping. Non-ionic (Triton X-100, Brij 35, Tween 20, Tween 60, Tween 80), cationic (CTAB, CTAC, DTAB, HPC) and anionic (DSS, SDS) compounds were selected to investigate the effect of surfactants on the voltammetric signal of cadmium. At the same time, the extent to which the addition of Amberlite resins to the analysed solution eliminates the interfering effect of surfactants was tested. Three types of Amberlite resins XAD-2, XAD-7 and XAD-16 were selected for the study and the ratio of resin weight to solution volume was determined. Finally, the determination of cadmium in surfactant-enriched environmental samples was carried out. The recoveries obtained between 95.5 and 107%, with RSD between 3.4 and 6.2%, confirm the validity and correctness of the proposed procedure All measurements were carried out by anodic stripping voltammetry using a CNTs/SGC electrode modified with a bismuth film as the working electrode.

Photochemical Hydride Generation in Sulfite Medium: Sample Introduction into an Inductively Coupled Plasma Mass Spectrometer for the Determination of Ultratrace Inorganic Arsenic.

This Technical Note reports a new UV photochemical hydride generation (PHG) of As(III/V) in a sulfite medium. Combining PHG for sample introduction with sector field inductively coupled plasma mass spectrometry (SF-ICPMS) for detection, we established a novel and ultrasensitive approach for the determination of total inorganic As. Arsine was generated simply by exposing arsenic solutions containing 2 mM of sodium sulfite to UV irradiation for 10 s with 1 mM of sodium formate for sensitivity enhancement. An impressive limit of detection of 0.2 ng/L for As, suitable for the quantitation of inorganic arsenic at ultratrace levels, was readily achieved. Formation of hydrated electrons and hydrogen radicals was experimentally validated, and this may be responsible for the reduction of the high-valent arsenic species. The PHG may also provide a new and useful alternative to conventional hydride generation and photochemical vapor generation for the determination of other trace elements, such as Se(VI) and Te(VI), and by other atomic spectrometric techniques.

Standard Operating Procedure for the analysis of trace elements in hydrothermal fluids by Inductively Coupled Plasma Mass Spectrometry (ICP-MS)

This standard operating procedure (SOP) validates an inductively coupled plasma mass spectrometry (ICP-MS) procedure for the trace element determinations in hydrothermal fluids. Hydrothermal fluids are aqueous solutions with a wide range of temperature, salinity, pH and trace elements that can be used by a set of microbial proteins containing redox-sensitive transition metals as their catalytic core. Due to the high variability of these samples, we have developed this protocol taking into account the special features of the matrices analyzed. An ICP-MS 7900 Agilent system was used. Calibration curves are linear in the 0.01 to 100 μg/L concentration range.

High-accuracy total reflection X-ray fluorescence analysis for determining trace elements using substrate cleaned by ammonia-hydrogen peroxide mixture

Total reflection X-ray fluorescence (TXRF) analysis is one of the useful techniques for determining trace elements. Owing to the high detection sensitivity of X-ray fluorescence in small residues, the hydrophobic substrates are generally used to form dot-type residue. However, when measuring low-Z elements in sample solutions with high concentrations of matrix elements, obtaining sufficient measurement sensitivity can be difficult. X-ray fluorescence is absorbed by the matrix elements, which means that the absorption effect increases in the thicker dried residue compared to the thinner dried residue. To avoid this absorption effect, we have proposed a thin film-type residue. In this study, the glass substrate was treated with an ammonia-hydrogen peroxide mixture (APM). The hydrogen peroxide decomposes organic components, and ammonia slightly etches glass materials. The APM-treated region was limited to a diameter of 6 mm by using a polytetrafluoroethylene mask placed on the glass substrate. As a result, the surface is refreshed to expose the hydroxyl group to make it superhydrophilic. The measured contact angle was 5°. By using the APM-treated superhydrophilic substrate to prepare dried residue, the net intensities in low Z elements were improved. The ratio of Al Kα intensity, calculated as net intensity in the APM-treated substrate divided by it in the hydrophobic substrate, was 2.29. The recovery of each element in the APM-treated substrate was almost 100%; however, recoveries of elements (Al, P, K, and Ca) in the hydrophobic substrate showed significant deviations from 100% (the recovery of Al was approximately 32%). In summary, we successfully improved both analytical sensitivity and accuracy in TXRF analysis by using the APM treated substrate.

Biological (microfloral) factors of influence on cytogenetic stability during chemical mutagenesis

ABSTRACT The article presents the results of a study of chromosomal mutations in residents living in the Aral Sea disaster zone. The present study was designed to evaluate the impact of the combined effect of a chemical mutagen (nickel) and bacterial microflora on the level of chromosomal aberrations (CA) in peripheral blood lymphocytes. This study used classical methods of cell cultivation, methods for determining chromosomal aberrations, a cytomorphological method for assessing epithelial cells, and an atomic absorption method for determining trace elements in the blood. The article shows that with an increase of chemical agent in the blood, the number of cells with features of damage and cells with contamination by microflora increases. Both of these factors cause an increase in the frequency of chromosomal aberrations. The article demonstrates how being exposed to a chemical factor increases chromosomal mutations, and also damages membrane components, which leads to a decrease in the barrier and protective function of the cell, and as a result also affects the level of chromosomal aberrations.

Determination of endogenous trace elements in extracellular vesicles secreted by an in vitro model of human retinal pigment epithelium under oxidative stress conditions using ICP-MS

The determination of endogenous Fe, Cu and Zn in exosomes (<200 nm extracellular vesicles) secreted by an in vitro model of the human retinal pigment epithelium (HRPEsv cell line) was carried out by inductively coupled plasma - mass spectrometry (ICP-MS). Results for cells treated with 2,2′-azobis (2-methylpropionamidine) dihydrochloride (AAPH) inducing oxidative stress (OS) conditions were compared with non-treated (control) cells in order to evaluate possible differences in the metal composition between both groups. Three sample introduction systems were tested for ICP-MS analysis: a micronebulizer and two single cell nebulization systems (as total consumption set-ups), being found one of the single cell systems (operating in bulk mode) as the most suitable. Two protocols for the isolation of exosomes from cell culture media were investigated based on differential centrifugation and precipitation with a polymer-based reagent. Transmission electron microscopy measurements showed smaller and more homogeneous sizes (15–50 nm versus 20–180 nm size range) together with a higher particle concentration for exosomes purified by precipitation compared to differential centrifugation. However, it was observed that the contribution of polymer-based protocol to the Fe, Cu and Zn blank was significant as compared to the differential centrifugation protocol. Therefore, considering the low concentrations of the evaluated endogenous elements in exosomes from the HRPEsv cell line, the polymer-based precipitation method was discarded. When comparing metal levels in samples from control versus OS-treated HRPEsv cells, results for Fe and Cu were statistically similar. However, upregulation of Zn was found during OS conditions (11 versus 34 μg L−1 in control and OS-treatment, respectively), showing Zn depletion through secretory activity induced by OS, underlying the antioxidant ability of RPE cells.

Nuclear analytical techniques used to study the trace element content of Centaurium erythraea Rafn, a medicinal plant species from sites with different pollution loads in Lower Silesia (SW Poland).

Centaurium erythraea (Gentianaceae) is a medicinal plant species with therapeutic potential officially listed in the pharmacopoeias of many European, Asian and American countries. It has had many uses in natural medicine since ancient times and it is collected mostly from wild populations. The aim of this study is to investigate the trace element composition of C. erythraea using instrumental neutron activation analysis (INAA). The results of the performed investigations show that INAA has proved to be an efficient analytical technique for the determination of trace elements in medicinal plants. The studied plant contains elements important to the human diet and metabolism that are needed for growth, development and the prevention and curing of disease. A comparison with the reference levels of elements for plants shows that the concentrations of most elements in C. erythraea collected from all types of sites exceed those regarded as the reference. Compared to the values of the elements in C. erythraea from rural areas (LP), the concentrations of most of the investigated elements in C. erythraea collected from the lignite basin, urban areas and in the vicinity of the A4 highway (MP) were significantly higher. The results obtained can be used for control and monitoring in the production of pharmaceuticals based on natural medical plants.

Lake-wide assessment of trace elements in surface sediments and water of Lake Sevan

Lake Sevan (Armenia) is one of the large freshwater high-mountain lakes of Eurasia. Detailed information about the extent and fate of trace elements on lake sediment and water quality has not been published yet. For this reason, surface sediment and water samples were collected from the southern and northern basins of Lake Sevan to determine trace element concentrations and assess the trace element behaviour. Geo-accumulation index, potential ecological risk index, and hazard index were calculated to estimate the environmental risk potential. In comparison to reference values, the investigated sediment samples contained elevated concentrations frequently for V, Cr, Co, Ni, Mo, Cd, Be, Ti, Rb, Sr, Se, Hf, and Th and occasionally for Cu, As, Li, B, Ag, Sb, Tl, Bi, U, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, and Tm. An overall potential ecological risk posed by all the investigated trace elements in the sediments was assessed to be moderate-considerable, however, Mo, Hg, and Cd were the elements with the highest ecological risk potential. The two basins of the lake showed significantly different behaviour according to the investigated trace element contents in the sediments to be higher in the bigger basin compared to the smaller basin. In comparison to reference concentrations in water samples according to the use of the adapted geo-accumulation index, elevated values for Ti, Cr, Cu, Cd, and Pb were observed. Elevated concentration was also observed in the case of B in nearly all water samples in comparison with literature values. Nevertheless, several water samples can be seen as not strongly anthropogenic influenced by Co, Ni, Sn, Sb, Ag, Hg, and Bi. The concentrations of trace elements in the lake water caused health risks to humans particularly children in the case of lake water used for drinking purposes, moreover, As was the main element posing health hazards. The results point out further attention to the sources of elevated trace elements in Lake Sevan, including anthropogenic influences and geological characteristics.

Optimization of ICP-MS internal standardization for 26 elements by factorial design experiment

IntroductionInternal standardization is a common tool used in inductively coupled plasma – mass spectrometry (ICP-MS) analysis in order to reduce matrix effects, and thus improve the reliability and the robustness of results. However, its efficacy relies on the choice of a proper internal standard (IS) which, ideally, undergoes the same signal variations as the analyte. Thus far, IS selection has mainly relied on the proximity of atomic mass between the analyte and the internal standard.However, while it may be a satisfactory rule of thumb, more recent works suggest that this criterium might not be suitable in several conditions, among which the presence of high amounts of carbon atoms in the sample. This may thus be of particular interest in the case of trace elements determination in biological samples. Materials and methodsIn this study, we propose an empirical and global approach to IS selection in ICP-MS through the use of a factorial design of experiments (DoE), with a focus on biological matrices of interest in clinical analysis: human blood and urine. The suitability of 13 potential IS was evaluated for 26 clinically-relevant analytes, including a polyatomic ion obtained through reaction with oxygen, across 324 experimental conditions. Results and discussionThe results underline several exceptions to the rule of IS selection based on mass proximity, notably when considering heavy or polyatomic analytes. As a consequence, measurements of said analytes in several extreme experimental conditions using IS selected by mass proximity could yield vastly erroneous results (up to 30 times the theoretical concentrations). By contrast, the use of empirically selected IS yielded much more acceptable results.

Determination of Serum Trace Elements and Oxidative Stress in Bitches with Transmissible Venereal Tumor

Background: This study was conducted to compare the changes in oxidative stress levels with some trace elements in blood serum in healthy bitches and bitches with transmissible venereal tumor (TVT). Methods: A total of 40 bitches were used in the study. According to the genital organ examinations, healthy bitches constituted the control group (n=20) and those with venereal tumors constituted the TVT group (n=20). Total oxidant status (TOS), total antioxidant status (TAS) and oxidative stress index (OSI) were determined spectrophotometrically. In addition, some serum trace element levels such as magnesium (Mg), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn) and selenium (Se) were measured using an ICP-MS analysis device. Result: The serum Se, Mg and Zn levels were lower in the TVT group compared to the control group (p less than 0.01) and serum Fe and Cu levels were higher in the TVT group than in the control group (p less than 0.01). Serum TOS and OSI levels were higher (p less than 0.001) and serum TAS levels were lower (p less than 0.001) in the TVT group compared to the control group. The study results showed that oxidative stress is high in bitches with TVT, and in parallel with this, changes occur in the amount of certain trace elements that are associated with oxidative stress.

Quantitative determination of trace elements in frozen and chilled chicken using ICP OES and related health risk assessment

A graphitic digestion method linked with inductive coupled plasma optical emission spectroscopy (ICP OES) instrument was used to determine the levels of trace elements in frozen and chilled chicken samples collected from markets in Jouf city, Saudi Arabia. The current method is innovative because samples are digested using a graphitic digestion system, which is safer, facile sample handling, short time for assessment, and more environmentally friendly than existing procedures. The results revealed that the chilled chicken samples contained higher concentrations of Na, Fe, Cr, and Mn than the frozen samples, which were below detection limit. Furthermore, the Cu, Al, Zn, and Cr contents in some of the analyzed chicken samples were over the maximum permissible limit of international standards, indicating a serious risk to consumers. The estimation of health-risk indicated that trace metal contamination causes health risks to the consumers, but the effect decreases with decreasing the target hazard quotient value in the rank of Cr > Al > Zn > Cu > Mn > Fe, with all values less than 1 except for Cr in chilled chicken. Moreover, the tolerable limit (1 × 10−6) for the carcinogenic risk for Cr in chilled chicken was observed to be exceeded.

Femtosecond Laser Ablation–Inductively Coupled Plasma Mass Spectrometry (fsLA-ICP-MS) for Direct Elemental Analysis of Rice

Easy, safe, and rapid quantitative methods to determine trace elements in agricultural products are required for efficient food safety management. Microwave-assisted digestion is traditionally used for trace elements in agricultural samples and accurate results and high selectivity are obtained. However, this procedure involves sample preparation, mixing, and extraction, which increases the time and complexity. Here we present femtosecond laser ablation–inductively coupled plasma mass spectrometry (fsLA-ICP-MS) to quantify arsenic, cadmium, and lead in rice. The recoveries by fsLA-ICP-MS for As, Cd, and Pb were 118.1%, 96.9%, and 87.1%, respectively, and 102%, 96.9%, and 107% by ICP-MS. The results by these techniques correlated well (>0.94) with the previously determined concentrations. The results confirm that fsLA-ICP-MS may be used to quantify trace elements in rice and is a promising, inexpensive, and easy-to-use alternative to traditional methods for food analysis.

Geochemical Records of the Late Glacial and Holocene Paleoenvironmental Changes from the Lake Kaskadnoe-1 Sediments (East Sayan Mountains, South Siberia)

Long-term and continuous lake sedimentary records offer enormous potential for interpreting paleoenvironmental histories and for understanding how terrestrial environments might respond to current global warming conditions. However, sedimentary records that contain the Late Glacial and Holocene epochs are scarce in deep continental high-mountain regions. A 150 cm sediment core was obtained from Lake Kaskadnoe-1 in the East Sayan Mountains (South Siberia, Russia, 2080 m above sea level), containing a unique record of the last 13,200 calibrated years (cal yr). Chronological control was obtained by AMS 14C dating. Here, we show the first detailed X-ray fluorescence (XRF) geochemical record, with the goal of broadening our knowledge of the paleoenvironmental history of the East Sayan Mountains in the past. The determination of major compounds and trace elements (Sr, Zr) was performed from each centimeter of the Lake Kaskadnoe-1 sediment core. The inorganic geochemistry indicates significant variations in elemental composition between two major lithological units of the sediment core: the Late Glacial dense grey silty clay (150–144 cm), and the upper interval (0–143 cm) mostly consisted of dark biogenic-terrigenous silt, accumulated during the Holocene. The Late Glacial sediments accumulated 13,200–12,800 cal yr BP are characterized by high values of CIA, Mg/Al, K/Al, and Mn/Fe, and are depleted in Si/Al, Fe/Al, and Ca/Al. During the Younger Dryas cold episode, LOI enrichment was probably caused by the presence of less oxic conditions, as seen in lower Mn/Fe values, due to a longer period of lake ice-cover. The Early Holocene (12,000–7500 cal yr BP) is associated with a decreasing trend of mineral matter with fluvial transport to Lake Kaskadnoe-1 (low K/Al, Mg/Al) and stronger chemical weathering in the lake basin. The increase in Ti/Al, K/Al and CIA values over the last 7500 years suggests an increase in the terrigenous input into the lake. Low LOI values can be possibly explained by the presence of less dense vegetation cover in the basin. In summary, our data indicate that the geochemical indices and selected elemental ratios mirror the sedimentation conditions that were triggered by environmental and climate changes during the Late Glacial and Holocene.

Tackling the Challenging Determination of Trace Elements in Ultrapure Silicon Carbide by LA-ICP-MS

The goal of accurately quantifying trace elements in ultrapure silicon carbide (SiC) with a purity target of 5N (99.999% purity) was addressed. The unsuitability of microwave-assisted acid digestion followed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analysis was proved to depend mainly on the contamination induced by memory effects of PTFE microwave vessels and by the purity levels of acids, even if highly pure ones were used in a clean environment. A new analytical protocol for the direct analysis of the solid material by laser ablation coupled with ICP-MS (LA-ICP-MS) was then exploited. Different samples were studied; the best results were obtained by embedding SiC (powders or grains) in epoxy resin. This technique has the great advantage of avoiding any source of external contamination, as grinding, pressing and sintering pretreatments are totally unnecessary. Two different laser wavelengths (266 and 193 nm) were tested, and best results were obtained with the 266 nm laser. The optimized protocol allows the determination of elements down to the sub-mg/kg level with a good accuracy level.

Determination of Immune-Boosting Trace Elements In Selected Fruit Seeds

The deluge of processed food in the world has led to an incalculable number of health problems and increased mortality. Consequently, a healthy and long life has become a gem that every human being is chasing in this modern society. Due to the lacuna of information about a healthy lifestyle, scientists have shifted their focal point to carry out painstaking research in the field of nutrition such as trace elements. Reviewing prior literature, it is evident that controlled intake of trace elements leads to healthy skin and hair, aids in blood sugar control, prevents osteoporosis, and is involved in protein synthesis, treatment of hypertension, and inflammatory conditions. Intake of large amounts of the elements brings about health problems lowering the body's immunity. This study analyzed trace elements of selected fruit seeds (watermelon seeds, orange seeds, pawpaw seeds, avocado seeds) commonly consumed in Kendu Bay, Homa Bay County, and club 36, Nairobi County to determine the moisture content and levels of trace elements in the seeds then compare the concentrations of the trace elements (Zn, Cu, Fe, Mg, Mn) in the various selected fruit seeds with the limits recommended by WHO and FAO. The wet digestion method was used to digest them after which they were analyzed by atomic absorption spectrophotometer. The average moisture content in orange, pawpaw, watermelon, and avocado seeds was 50.26%, 87.38, 72.19%, and 63.75 respectively. The levels of the trace elements were analyzed using atomic absorption spectrophotometer (AAS). The results indicated that all the trace elements positively correlated with copper, giving a strong correlation coefficient (r=0.9997) with a regression equation of y=0.0238x-0.0002, while manganese had the lowest correlation (r= 0.9617). Pawpaw seeds from Kendu Bay had the highest levels of zinc (0.6020±0.5794mg/kg), magnesium (4.2270±0.1479mg/kg), and manganese (0.2743±0.0564mg/kg). Avocado seed from club 36 had the lowest levels of zinc (0.2102±0.0076mg/kg) and magnesium (1.6063±0.0594mg/kg). Orange seeds from club 36 recorded the highest levels of copper (0.1597±0.0005mg/kg), while pawpaw seeds from club 36 recorded the lowest levels of copper (0.1177±0.0004mg/kg). It is evident from the results that magnesium was the abundant trace mineral in all the fruit seed samples, with a concentration of 4.2270±0.1479mg/kg in pawpaw seeds from Kendu Bay. Manganese and copper recorded the lowest levels across all samples. Comparing the results with WHO/FAO permissible limits for trace minerals in food, all elements in the fruit seed samples were below and within the permissible levels. Iron contents were below the detection limit in all samples. The findings of this study will provide additional information on the immune-boosting trace elements present in the selected fruit seeds from Kendu Bay and Club 36, Nairobi. The study will be of great importance to nutritionists, consumers worldwide, and health agencies in creating awareness of the health benefits of fruit seed consumption

Trace Element Analysis and in vitro Bioactivity of Parkia roxburghii and Rhus semialata extracts

A study on the fruit of Parkia roxburghii and Rhus semialata, specifically found in Nagaland, is being done in this work which includes its phytochemical screening, trace element determination, anti-bacterial and antioxidant studies. Acetone and Ethanol were used for the extraction purpose. Furthermore, in vitro antioxidant studies for determining its free radical scavenging activity were carried out through the DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) assay as compared with the reference standards Trolox and Ascorbic acid. The extracts were also evaluated for their anti-bacterial activity against four strains of bacteria and to further quantify the anti-bacterial studies, the MIC (Minimum Inhibitory Concentration) of both the samples were carried out by means of two-fold serial broth dilution method.

Determination of Cr, Se, Ge, and V in Hypothyroidism Patients by Using Graphite Furnace Atomic Absorption Spectrometry and mixture matrix modification

A simple, accurate and rapid method was developed for routine determination of trace elements in blood serum. The method based on the direct determination for Cr, Se, Ge, and V in hypothyroidism patients before therapy. By using atomic absorption spectrometry with graphite surface coated and uncoated pyrolysis GF-AAS, and a mixture of palladium nitrate and magnesium nitrate as the matrix modifier, with deuterium background correction and no sample pretreatment except dilution was necessary. This permitted direct determination hence the risk of sample contamination was reduced. Further, the use of graphite surface-coated GF-AAS decreased the ashing and atomization temperatures of Cr, Ge, and V to values that were lesser than the corresponding values obtained using uncoated pyrolysis GF-AAS, by 100°C; in case of Se, the atomization temperature decreased to a value that was 200°C lesser than that obtained using uncoated pyrolysis GF-AAS.&#x0D; A mixture of (3µL) palladium nitrate, and (2µL) magnesium nitrate was successfully applied to improve the sensitivity, reproducibility, recovery, limit of detection and the accuracy of the measurements. The correlation coefficients of the calibration curves of Cr, Se, Ge, and V were found to be (0.9999, 0.9999, 0.9995 and 0.9999) respectively, the relative standard deviation of the measurements for Cr, Se, Ge and V were (0.027, 0.075, 0.054 and 0.068) respectively. The statistical analysis of the acquired data showed acceptable accuracy. The analyses thus performed indicated that the levels of serum trace elements Cr, Se, Ge, and V in hypothyroidism patients were lower than those in the control group.

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

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.