Trace Elements In Food Research Articles

Food surveillance in the Basque country (Spain) I. The design of a total diet study

A total diet study has been initiated in the Basque country (Spain), the purpose of which is to provide estimates of the average intake of both food contaminants and certain nutrients. The types and quantities of foods that make up the average Basque 'Total Diet' are based on the results of surveys carried out between 1988 and 1990. These surveys have identified the major items in the national diet (91 categories of foods) which are combined for the total diet study, for analysis, into 16 groups of similar foods. Each group is being analysed for selected contaminants of concern which initially are: heavy metals (mercury, lead, cadmium and arsenic), organochlorine pesticides (HCB, HCH (alpha, beta, gamma, delta), DDT (DDE, TDE), dieldrin, aldrin, endrin, heptachlor, heptachlor epoxide, endosulfan and methoxychlor) and selected trace element nutrients (zinc, selenium and iron). In the milk and dairy products groups an assessment of aflatoxin M1 contamination is also being carried out.

Trace analysis: soils

Determinations of constituents present in soils and soil solutions at trace concentrations are conducted primarily because of interest in soil as a medium for plant growth or because of its influence upon the solute chemistry of fresh waters and ground waters. Interest may arise from concern over potential toxicity effects or over adverse effects of deficiency of trace nutrient elements essential to soil or freshwater biota. In the above context, total amounts of elements present in soil are generally of less interest than water-soluble or labile, plant available forms (Marr & Cresser 1983). Rhizosphere soil may be more relevant than bulk soil in assessing plant availability. Over recent decades, optimal chemical extractants (such as EDTA or DTPA for Zn and Cu) have been selected which reflect plant availability of trace elements in terms of high correlations between plant tissue and soil extract concentrations. Occasionally full speciation is conducted. M. S. Cresser & E. El-Sayad (unpublished results), for example, have measured water-soluble, exchangeable and organically bound trace elements, and those in carbonate and amorphorus and crystalline iron and manganese oxides, and residual sand, silt and clay minerals. Such detailed analysis is valuable in elucidation of soil pedogenesis (El-Sayad et al . 1988).

Investigation of trace element content of cheese

Nine trace elements (Al, Cr, Mn, Fe, Ni, Cu, Zn, Cd, Pb) were determined in cheese by atomic absorption spectrophotometry with electrothermal atomization in a graphite tube, using the ashing procedure. Associations among mineral constituents were studied by means of principal component analysis, which allows determination of interdependences among trace elements in foods. A test for normality was used to investigate monovariate distributions, in order to estimate the symmetry of data vector. The correlation matrix was used as a starting matrix for principal component analysis; nine variables were reduced to four principal components. The clusters of elements appear to be determined by their origin.

Evaluation of inductively coupled plasma mass spectrometry for the determination of trace elements in foods.

Evaluation of inductively coupled plasma mass spectrometry for the determination of trace elements in foods.

Determination of trace elements in food by neutron activation analysis

Neutron activation analysis (NAA) methods have been developed for the determination of major, minor and trace elements in duplicate diets and individual food items. These include a cyclic instrumental NAA (CINAA) method for measuring Se content through its short-lived nuclide77mSe; epithermal INAA (EINAA) for I and As; conventional INAA for Br, Ca, Cl, Co, Cr, Fe, K, Mg, Mn, Na, Rb, Sb, Sc, Sn and Zn; combination of EINAA and INAA for Al; radiochemical NAA (RNAA) for As, Au, Co, Cu, Fe, Hg, Mo, Sb, Se and Zn; and preconcentration NAA (PNAA) for U and Th. Accuracy of measurements have been evaluated by analyzing a number of biological and diet reference materials. Multielement concentrations of diets and foods have been measured by these methods.

A Review of the Role of Manganese in Pine Plantations

SYNOPSIS The literature on the physiological role of manganese in trees is reviewed. Manganese (Mn) deficiency is associated with strongly-podzolised soils and good drainage. Deficiency symptoms and foliar nutrient trace element levels are given for the Southern Cape. Future research should concentrate on soil tests: monitoring of foliar levels in second-rotation stands and the evaluation of enzymatic physiological assay techniques.

Characterization of a potato reference material for major, minor and trace elements

A potato reference material (RM) was prepared for the analytical quality control program to be employed by the Sub-network on Trace Elements in Food of the FAO European Co-operative Network on Trace Elements. Approximately 50 kg of commercially available potato granules prepared from baked, mashed and roller-dried potatoes, containing 2.8% ash and 3 mg/kg added butylhydroxyanisole was purchased. The granules were carefully homogenised in large glass cylinders followed by division into 50 g portions into numbered acid-washed bottles. The bottled material was tested for homogeneity by taking ten bottles throughout the bottling line and determining by validated atomic absorption spectrometric methods 1.0 g samples for seven mineral elements. Homogeneity for Mg, Ca, Zn, Fe, Mo, Ni and Cd was better than 5%. An international network on experienced, high-quality reference laboratories was established to conduct an interlaboratory comparison study on the determination of 14 mineral elements in the RM. A total of seven methods based on independent analytical principles were employed by the reference laboratories. After excluding outlying analytical results, the criteria defined by the IAEA were used for classification of the overall medians obtained through the interlaboratory comparison study. The relative standard deviations for the 95% confidence limits of the medians were as follows: P=4.2%, K=0.7%, Na=4.7%, Ca=5.5%, Mg=2.4%, Fe=9.3%, Mn=4.0%, Zn=3.6%, Cu=4.7%, Mo=23%, Ni=22%, Cr=19%, Pb=11% and Cd=4.6%. With the exception of Cr, all of the recommended concentration values obtained for the above indicated elements fell into category A, i.e. values recommended with a high degree of confidence according to the classification criteria of the IAEA. The present RM is the only certified potato RM currently available for mineral elements.

Ocean chemical fluxes 1983–1986

This review covers U.S. contributions in marine chemistry 1983–1986 in the areas of nutrient chemistry, carbon cycle, trace elements, oxygen cycling, radioisotopes (natural and artificial), particles and primary productivity. In most cases a simple review of important trends in this very large and diverse literature set is all that can be considered. The literature explosion in these areas results in more than 350 references.

Analytical quality control program used by the trace elements in foods and diets sub-network of the FAO European cooperative network on trace elements

The analytical quality control program employed by the ongoing FAO study on 14 trace elements in nationally representative staple foods of European countries is presented. The analytical quality control used is based on: 1) precautions taken to avoid trace element contaminations or losses during sampling and sample handling; and, 2) on methods used to guarantee that the actual determinations yield correct results. The precautions are presented. A number of certified biological reference materials (RMs) were used to validate the analytical methods employed. The following staple food RMs were also prepared: wheat flour, potato powder, animal muscle (pork) and milk powder. They were tested for homogeneity and subjected to an interlaboratory comparison study on the basis of which recommended values for trace element concentrations were defined. Further, the mean relative standard deviation for the 95% confidence limits of the medians in all RMs was below 5% for Ca, Mg and Zn; below 10% for Mn; below 15% for Fe, Cu and Se; and below 25% for Mo and Ni. These RMs were used to control the analytical quality of the trace element determinations in the actual samples. It is concluded that important contaminations were avoided in sampling and sample handling and that use of the RMs described was necessary to guarantee the analytical quality of the results.

The epidemiology of dental caries in relation to environmental trace elements.

This paper reviews the influence of the geochemical environment on the epidemiology of human dental caries. The best documented association is that between water borne fluoride and reduced caries prevalence. The influence of fluoride was first reported during the early decades of this century in Colorado, USA, and led to the fluoridation of some public water supplies in several countries. In all cases, fluoridation has been followed by significant improvements in dental health and no adverse effects in general health. Other trace elements in food and water have now been linked with dental caries. Molybdenum has been associated with reduced caries prevalence whereas selenium and lead appear to have adverse effects. Cavity formation in teeth probably involves a localised dissolution of the enamel surface by the products of bacterial activity. It is possible that the incorporation of trace metals into the apatite microcrystals of enamel may alter their physical properties, especially solubility, and hence their susceptibility to degradation.

Determination of Trace Elements in Foods by HCl-HNO3 Leaching and Flame Atomic Absorption Spectroscopy

Aluminum, iron, tin, zinc, calcium, magnesium, nickel, copper, chromium, cadmium, and potassium in foods can be extracted by HCl-HNO3 leaching and determined quantitatively using flame atomic absorption spectroscopy (AAS), with recoveries ranging from 90 to 110%. Thirty to 40 samples of almost any type of food sample can be analyzed routinely for 2 elements in 4-5 h. In contrast, one or 2 days are required when a wet-ash or dry-ash technique is used. Extraction consists of weighing 2-10 g samples into 125 mL Erlenmeyer flasks, adding 20 mL concentrated HCl-HNO3 (9 + 1), then heating in a 82- 93 degrees C water bath for 30 min. After cooling, samples are diluted to volume in 50 mL Nessler tubes and then filtered through No. 541 or 540 Whatman paper. The filtrate is analyzed directly by AAS.

Cobalt content of foods and diets in a Spanish population (short communication).

The WHO Expert Committee on Food Contaminants has pointed out the need of determining the content of foods in trace elements in order to ascertain their contribution to the total intake of oligoelements through the diet. Since the contents in trace elements depend on the environmental features, it is necessary to carry out systematic determinations of trace elements in foods of local origin in order to know the exposure level of population. This work intends to study the cobalt contribution through the diet. The element intake is calculated from the cobalt content in raw foods after elimination of the non-eatable moiety by flame atomic absorption spectroscopy, after formation of a chelate with ammonium pyrrolidine dithiocarbamate (APDC) and extraction with 4-methyl-2-pentanone (MIBK) according to a procedure developed and verified in a previous paper.

Report by the Analytical Methods Committee: the determination of trace elements in food by atomic-absorption spectrometry

Report by the Analytical Methods Committee: the determination of trace elements in food by atomic-absorption spectrometry

4: Trace elements in food and drink products

Nutrition BulletinVolume 8, Issue 3 p. 146-148 4: Trace elements in food and drink products First published: September 1983 https://doi.org/10.1111/j.1467-3010.1983.tb01328.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume8, Issue3September 1983Pages 146-148 RelatedInformation

Surfactant-hypochlorite digestion of food matrices for trace analysis of chromium and molybdenum

Hypochlorite solution and a surfactant as wetting agent digests most food matrices at room temperature (18–25°). Food trace elements can be determined from the digest with minimal processing. Chromium trace is determined directly in the aqueous phase of the digest. Molybdenum trace is reduced to a lower oxidation form, chelated, and extracted from the aqueous by an anoxic organic immiscible solvent. Each trace element is determined separately by means of a spectrophotometer. The chromium is made strongly absorbing with hematoxylin chelation. The organically soluble dibutyldithiocarbamate of low oxidation forms of molybdenum are strongly absorbing in the visible region of the spectrum, and absorbance can be further enhanced by evaporation of most of the solvent at or near room temperature (18–25°).

The concept of preconceptual care

After examining the increase in congenital defects among children, the author investigates the effects of trace elements in food on health. Some remedies are suggested as regards nutritional deficits. The author's technique of hair analysis is described in some detail in regard to trace elements. Particular attention is then paid to nutritional disorders in children and their prevention.

Polarographic determination of trace elements in food from a single digest

The determination of 12 trace elements, namely copper, zinc, mercury, lead, cadmium, iron, tin, chromium, arsenic, antimony, selenium and tellurium, in admixture by means of a cathode-ray polarograph is described. The elements were investigated in concentrations ranging from 0.1 to 20 p.p.m. by means of normal, reverse-sweep or resistance-capacitance derivative techniques. The last technique could not be used for mercury, although it was used for all the other elements in concentrations less than 1 p.p.m. The complete determination took 4–7 h, and was applied to various kinds of food, such as bread, meat and vegetables.

Nutrient Trace Element Composition of Foods: Analytical Needs and Problems

Nutrient Trace Element Composition of Foods: Analytical Needs and Problems

Nutrient trace element composition of foods: analytical needs and problems.

Nutrient trace element composition of foods: analytical needs and problems.

Metals in the Life of Man*

The importance of metals in the life of mankind has generally been thought of as beginning with the bronze age, about 2000 years before Christ when men discovered that by mixing tin and copper (probably known as early as 5000 B.C.), a beautiful, durable, gleaming, new material became available to them to enrich their art, to implement their trade and industry as well as to enable them to fashion more destructive instruments of war. Actually, metals were vital factors in man's life many millions of years earlier. They have been an essential part of all cellular metabolism since the most primitive life began. Most of them are present as trace elements--those that constitute less than 0.01 per cent of the organism (1)mand since capabilities for measuring metals beyond parts per million have only recently been available, it is difficult to estimate how many may be present in the human body. Their action. except when present in overwhelming concentrations, is largely through their influence on enzymes: acting catalytically, as co-enzymes or as structural components of the enzyme system. In some, the metals are firmly bound, in others they come and go readily with changes in the chemical environment. Since a large number of the body's enzymes, perhaps S0 per cent, are metallo enzymes, they constitute a most important area of influence in human metabolism. Until recent years, the clinician has been concerned primarily with heavy metals such as arsenic, lead and mercury and more recently cadmium, cobalt and nickel. It appears likely that a far more important area for study than heavy metal poisoning is that of the essential metals whose range of concentration within the cell may be critical and narrow. These metals, unlike their fellow nutrients, the vitamins, cannot be synthesized and the cell is utterly dependent on its environment for their supply, By the same token, an excess in the environment may present as great a problem since both excesses and deficiencies can kill. An early pioneer in the study of the biological role of metals was a physician, Dr. Henry A. Schroeder. Some 20 years before his death, he left a practice and teaching position in St. Louis. acquired a few acres of rocky soil atop a mountain in Vermont and built the first laboratory for the exclusive study of the role of trace elements in health and disease. Designed to raise animals in an environment free of metals, it was constructed without nails. Building materials were analyzed for lead and cadmium. Polyethylene and acrylic plastics were used throughout (2). In order that contamination from the atmosphere be prevented, the laboratory was pressurized from within, and air was brought in from the forest through large conduits equipped with electrostatic filters. All visitors were excluded from its animal rooms and all persons entering were required to wear special clothing. Here, Dr. Schroeder exhaustively studied the occurrence of 20 trace elements in food, water, soil, vegetation and animal and human tissues