Determination of Major and Minor Elements in the <Emphasis Type="Italic">Malva sylvestris</Emphasis> L. from Turkey Using ICP-OES Techniques

In this work, Malva sylvestris var. mauritiana (L.) leaves were collected from different points in Muradiye region of Manisa-Turkey. The leaves were dissolved by wet digestion method using a mixture of mineral acid. Concentrations of Ag, Al, B, Ba, Bi, Ca, Cd, Co, Cr, Cu, Fe, K, La, Mg, Mn, Na, Ni, Pb, Sn, Sr, Sb, Si, Ti, U, Zn, and Zr in prepared solutions were determined by using inductively coupled plasma optical emission spectrometry (ICP-OES). High Ca (13,848 mg/kg) and Mg (1,936 mg/kg) concentrations were found at the leaves. Obtained values were compared with the internationally permitted (standard) values. The results of elements were analyzed statistically (analysis of variance test). For different leaf sizes, concentration factors were calculated.     

Assessment of reference values for hair minerals of Korean preschool children

Hair samples of 655 children (3–6 yr of age) from metropolitan and small cities in Korea were analyzed to determine the content of 23 minor and trace elements with the aim of assessing reference values. Fifteen essential elements (Fe, Zn, Cu, Ca, Mg, Mn, P, Na, K, Cr, Se, Li, V, Co, Mo) and 8 harmful elements (Pb, Al, Hg, As, Cd, Ba, Bi, U) were taken into account. Measurements were performed by inductively coupled plasma-mass spectrometry. The overall mean values were as follows (μ/g): Al, 8.78; As, 0.11; Ba, 0.32; Bi, 0.04; Ca, 212.47; Cd, 0.08; Co, 0.01; Cr, 0.47; Cu, 15.51; Fe, 12.62; Hg, 0.49; K, 34.10; Li, 0.01; Mg, 12.29; Mn, 0.29; Mo, 0.07; Na; 27.14; P, 121.21; Pb, 1.68; Se, 0.75; U. 0.04; V. 0.08; Zn, 69.99. There was no significant difference in hair mineral content between children living in metropolitan and small cities. There were positive correlations between age and the level of Zn, Ca, Na, P, Mn, and Li, but negative correlations between age and the level of Cr, V, and U. The proposed reference values for hair Zn, Mg, Ca, As, and Cd of Korean children were lower than those of other countries, but the values for other elements of hair were not significantly different from those of other countries.     

Accumulation of Minerals by Leccinum scabrum from Two Large Forested Areas in Central Europe: Notecka Wilderness and Tuchola Forest (Pinewoods)

Leccinum scabrum sporocarps and associated topsoils from two areas in Poland have been characterized for contents and bioconcentration potential of Ag, Al, Ba, Ca, Cd, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sr and Zn. Topsoil and fruitbody element composition varied between the two study sites, most likely as a result of local soil geochemistry. Element content of the labile fraction in topsoil from both sites followed the ‘pseudo‐total’ fraction and median values (mg kg^?1 dry matter) were: K 380 and 340, Mg 760 and 840, P 1100 and 920, Al 3800 and 8100, Ag 0.31 and 0.28, Ba 28 and 37, Ca 920 and 790, Cd 0.23 and 0.23, Co 2.0 and 1.7, Cu 3.2 and 3.6, Fe 2800 and 6300, Mn 280 and 180, Na 99 and 110, Ni 7.8 and 8.8, Pb 12 and 18, Rb 1.3 and 2.1, Sr 4.8 and 4.0 and Zn 22 and 19, respectively. Only for some elements such as K, Mg, Al, Ag, Ca, Co, Mn, Na, Ni, Sr and Zn we found concentration differences between the two study sites for the caps of sporocarps. With the exception of Al, Mn, Na and Pb, stipes showed a similar tendency. Caps had a higher concentration of K, Rb, P, Mg, Al, Ag, Cu, Fe, Zn, Cd, Pb and Ni compared to stipes, while Na, Ba and Sr contents were higher in stipes. The comparison of soil and fruitbody concentrations indicates that L. scabrum bioconcentrate some elements while others are bioexcluded.     

Mineral Composition of Human fascia lata

The mineral composition of pathologically unchanged human fascia lata was examined here using inductively coupled plasma optical emission spectrometry (ICP-OES) method for the first time. The total concentrations of Ag, Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, P, Pb, Sr, Ti, V and Zn were simultaneously measured in the tissue secured during autopsy. The age-related changes and between-gender differences in mineral composition of the examined tissue were investigated and discussed.     

Age-related changes in the concentrations of major and trace elements in the brain of rats and mice

Age-related changes in the concentrations of constituent elements in the brains of rats and mice 1 wk to 24 mo old were determined with inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). Seventeen elements could be determined with reasonable accuracy and reproducibility. They were P, K, Na, Mg, Ca, Fe, Zn, Cu, Rb, Al, Mn, Sr, Mo, Co, Pb, Cs, and Cd in order of concentrations in the adult rat brains. In these elements, six major elements (P, K, Na, Fe, Mg, Ca) were determined with ICP-AES and the others with ICP-MS. The concentrations of each element and the pattern of age-related changes were similar between the rat and mouse brains. The elements of which concentrations decreased with aging were K and Rb. On the other hand, the concentrations of some metal elements, including Fe, Cu, Sr, and Co, appeared to increase with growth and aging. The concentrations of other elements were relatively constant throughout the age examined.     

Competition for minerals between Acanthocephalus lucii and its definitive host perch (Perca fluviatilis)

Concentrations of various essential and toxic elements (Ba, Ca, Co, Cu, Fe, Mg, Mn, Sr, Zn and Al, Ag, Cd, Cr, Ni, Pb, Tl) were analysed by inductively coupled plasma mass spectrometry in the acanthocephalan Acanthocephalus lucii and in different tissues of its host Perca fluviatilis. Nearly all the elements were found in significantly higher concentrations in the acanthocephalan than in the host tissues. Spearman correlation analysis revealed several strong inter-element associations within the organs of perch and within the parasites. Furthermore, statistical analysis revealed different competitive interactions. The concentrations of several essential elements (Ba, Ca, Fe, Mn, Sr and Zn) within the parasites decreased with an increasing number or weight of worms inside the intestine of the host. Additionally, the levels of some elements in the perch liver were negatively correlated with the weight of A. lucii in the intestine. Thus, it emerged that not only is there competition for essential elements between acanthocephalans inside the gut but there is also competition for these elements between the host and its parasites.     

Age-related effects of major and trace element concentrations in rat liver and their mutual relationships

The concentrations of 22 major and trace elements in livers from rats aging from 5 to 113 weeks old were determined. The rats investigated were the same rats previously reported with respect to 29 elements in bones (femur) and 26 elements in kidneys. The samples were decomposed with high-purity nitric acid and hydrogen peroxide. Seven elements (Na, Mg, P, K, Ca, Fe and Zn) were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES), and 15 elements (Mn, Co, Cu, As, Se, Rb, Sr, Mo, Cd, Sn, Sb, Cs, Ba, Pb and Bi) were determined by inductively coupled plasma mass spectrometry (ICP-MS). Analysis of variance (ANOVA) for age variations indicated that the concentrations of many elements, such as Mg, P, K, Mn, Fe, Cu, Zn, Sr, Mo and Cd, were almost constant across the ages of the rats with the exception of 5 weeks old (p > 0.05). Arsenic, Pb and Bi showed significant increasing trends, while Na and Co showed decreasing trends (p < 0.01). Selenium showed a decreasing trend except at the initial stage of 5–9 weeks old. Calcium, Rb, Sn, Sb, Cs and Ba showed significant age-related variations, but their patterns were not monotonic. The liver clearly contrasts with the kidneys, in which many elements showed significant age-related variations with increasing trends. The concentration ranges of Mg, P, K, Mn, Cu, Zn, and Mo were controlled within 15% across all ages of rats. The homeostasis of the aforementioned elements may be well established in the liver. The toxic elements, such as Cd, Pb and Bi, showed a narrow concentration range among age-matched rats.     

Elemental fingerprinting of tumorous and adjacent non-tumorous tissues from patients with colorectal cancer using ICP-MS, ICP-OES and chemometric analysis

Tumorous and adjacent non-tumorous paired biopsies from 38 patients with colorectal cancer were analyzed by inductively coupled plasma mass spectrometry and inductively coupled plasma optical emission spectrometry after low-volume microwave digestion. 18 elements were investigated: Ag, Al, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Ni, P, Pb, S, Se and Zn. Different chemometric tools were used for data evaluation: Wilcoxon signed rank test, Hieratical clustering analysis, principal component analysis (PCA) and linear discriminant analysis (LDA). With the exception of Al, tumours were observed to have significantly more elevated concentrations of essential elements as compared to non-tumours. On the contrary, elements considered potentially carcinogenic such as Cr, Ni, Mo or Co do not display significant differences. When PCA was applied, different components were obtained for tumorous and non-tumorous tissues. When LDA was applied for the elements studied (including essential and non-essential elements) about 90% of cases were correctly classified.     

Elemental Profile of Propolis from Different Areas of Serbia

Propolis is a resinous natural substance collected by honeybees from different plant sources. The element content of propolis is influenced by the content of elements in the soil, climatic factors, and the degree of pollution. The aim of the study was to characterize element composition and content of toxic elements in 51 propolis collected from different locations in Serbia and to evaluate the differences among them. Determination of the 21 elements were performed using Inductively coupled plasma - optical emission spectrometry. K was the most abundant element, followed by Ca, Mg, Si, Fe, Zn, and Al. The microelements B, Ba, Mn, Na, Pb, and Ti were also present in propolis, while Co, Cr, Cu, Mo, Ni, Sr, and V were found in trace. Toxic elements such as Pb, As, and Cd were found in the trace. Kruskal-Wallis tests differentiate groups of samples by geographical origin. The presence of B, Fe, Sr, Ti, Zn, and As demonstrated statistical significance between six regions of Serbia.     

Trace and mineral elements in royal jelly and homeostatic effects

Royal jelly from Apis mellifera is a highly active natural biological substance and is probably one of the most interesting raw substances in natural product chemistry. Trace elements play a key role in the biomedical activities associated with royal jelly, as these elements have a multitude of known and unknown biological functions. For this reason concentrations of 28 trace (Al, Ba, Sr, Bi, Cd, Hg, Pb, Sn, Te, Tl, W, Sb, Cr, Ni, Ti, V, Co, Mo) and mineral (P, S, Ca, Mg, K, Na, Zn, Fe, Cu, Mn) elements were systematically investigated in botanically and geologically defined royal jelly samples. In addition, concentrations of 14 trace elements were measured in the associated honey samples--honey being the precursor of royal jelly. Concentrations of K, Na, Mg, Ca, P, S, Cu, Fe, Zn, Al, Ba and Sr in royal jelly were determined by inductively coupled plasma optical emission spectroscopy (ICP-OES), while concentrations of Bi, Cd, Hg, Pb, Sn, Te, Tl, W, Sb, Cr, Mn, Ni, Ti, V, Co and Mo in royal jelly were determined by double focusing magnetic sector field inductively coupled plasma mass spectrometry (SF-ICP-MS). In the honey samples, trace and mineral element concentrations strongly depended on botanical and geological origin, and substantial variation was found. In contrast, the concentrations of trace and mineral elements were highly constant in the associated royal jelly samples. The most important results were the homeostatic adjustments of trace and mineral element concentrations in royal jelly. This effect was evidently produced in the endocrine glands of nurse bees, which are adapted for needs of bee larvae. In conclusion, this research yielded a surprising and completely new finding--that royal jelly, as a form of lactation on the insect level, shows the same homeostatic adjustment as mammalian and human breast milk.     

Analysis of trace metals in the Antarctic host-parasite system Notothenia coriiceps and Aspersentis megarhynchus (Acanthocephala) caught at King George Island,South Shetland Islands

Concentrations of the elements Al, Ag, As, Ba, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Sr were analysed by high-performance quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) in the acanthocephalan Aspersentis megarhynchus and in different tissues of its final host, Notothenia coriiceps. Infected fish were sampled at King George Island, South Shetland Islands, Antarctica. Most of the elements were found at significantly higher concentrations in the acanthocephalan than in muscle, liver and intestine of its host. Only Fe was concentrated in fish liver to a significantly higher level than in the parasite. Compared with the host tissues, the highest accumulation rates in A. megarhynchus were found for Pb, Cd, Ag, Ni and Cu. The acanthocephalans showed very high Ag and Pb levels, whereas the concentrations in the fish tissues were close to the detection limit. This study is the first proof that the enormous heavy-metal accumulation capacity reported for acanthocephalans from freshwater fish also occurs in acanthocephalans parasitizing marine fish. Consequently, acanthocephalans can be used to assess the occurrence and availability of even the lowest metal concentrations in all kinds of aquatic habitats, including remote areas such as the Antarctic.     

Genetic aspects of the interrelation between alkaloids and chemical elements in <Emphasis Type="Italic">Atropa belladonna</Emphasis> L. and <Emphasis Type="Italic">Glaucium flavum</Emphasis> Crantz. Plants

The variability of the contents of tropane and isoquinoline alkaloids, ashes, Na, K, Ca, Mg, Fe, Mn, Cu, Zn, Co, Mo, Cr, Al, Ba, V, Ni, Sr, Cd, Pb, J, and Ag was studied in individual plants of the industrial population of belladonna (Atropa belladonna L.) and yellow horned poppy (Glaucium flavum Crantz.). Numerous linear and nonlinear correlations of isoquinoline and tropane alkaloids with ashes and mineral elements were revealed by means of correlation and regression analyses. Alkaline earth elements (especially Sr and Ba) were shown to have a major role in the regulation of tropane alkaloid accumulation in belladonna leaves. K and Ni were of particular importance in the aerial part of yellow horned poppy. These elements at the suboptimal concentrations were most favorable for isoquinoline alkaloid accumulation in yellow horned poppy. Analytical mathematical models were derived for the regulation of alkaloid metabolism in test plants by some mineral elements (Ba, Mg, Al, Sr, Ni, Mn, and K). Our results indicate that the interrelation between alkaloids and elements in these plants is genetically determined.     

Accumulation of heavy metals by aquatic mosses. 2: Rhynchostegium riparioides

A study was made of general ecology and metal accumulation in the widespread aquatic moss Rhynchostegium riparioides, (Hedw.) C. Jens. with a view to developing the use of this species as a monitor of heavy metal pollution. In order to establish a data bank for statistical analysis, samples of water and moss were taken within a 6-week period from 105 sites (10-m reaches) in Northern England from streams and rivers of diverse physical and chemical types. Analyses were made of 14 metals (Na, Mg, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Ba, Pb) in both 2-cm tips and whole plants. The same 14 metals were also measured in both total and filtrable water, together with 12 other variables. Samples of tips were easier to prepare for analysis, but had significantly (p < 0.001) lower concentrations of all metals except Na and K. Significant correlations (p < 0.001) between metal in moss and aqueous metal were found for ten metals (Na, K, Mg, Ca, Mn, Cu, Zn, Cd, Ba, Pb). Correlations between metals in moss and in water were in general similar for tips and whole plants, but much higher for tips with Na, Zn and Cd; the relationship was quite similar whether total or filtrable water was considered, with the exception of Ba where the correlation was much higher with the latter. A multiple regression was used to suggest which variables in water and/ or moss may influence accumulation of Co, Ni, Cu, Zn, Cd, Ba and Pb in the moss. For instance, the variables which had a very highly significant effect on Pb in tips were Pb, filtrable reactive phosphate and Zn in the water. A discussion is included of how the data may be used for monitoring purposes.     

Study of the age and sex dependence of trace elements in hair by correspondence analysis

The aim of the study was to examine the potential of multidimensional analysis, and in particular of correspondence analysis (CA), in bringing to light the influence of sex and age on trace element (TE) concentrations in hair from an unselected French population. Sixteen elements (S, Hg, Se, Zn, Pb, Cd, Ni, Co, Mn, Fe, Cr, Mg, Al, Ca, Cu, Ag) were assayed by inductively coupled argon plasma (ICAP) emission specrroscopy in the scalp hair of 135 men and 346 women. In spite of the high background noise, CA was able to reveal the differing patterns in males and females. For instance, in this population, higher relative levels of the essential elements, Ca, Mg, Zn, and Cu, but also of Ag, characterized women’s hair, whereas higher relative levels of the heavy metals, Fe and Pb, were associated with men’s hair. Al and Ag were unexplainedly high in the hair of the youngest members of the population. The Cu and Co of youth seemed to give way to a predominance of Zn in maturity. The hair of individuals in their forties tended to be richest in Ca and Mg, but these elements decreased with advancing age. Heavy metals (Hg, Pb, Fe) accumulated with age, whereas Se, Mn, and Cr seemed independent of age. CA is manifestly a very useful tool for revealing underlying dimensions in complex dynamic systems and unsuspected relationships among variables. Clearly, the significance of the high Al and Ag contents in the hair of certain members of the population, especially of the very young, needs to be investigated from both physiological and toxicological aspects.     

Establishment of Element Fingerprint and Multielement Analysis of Fritillaria thunbergii by Inductively Coupled Plasma Optical Emission Spectrometry

Element fingerprints were deciphered for Fritillaria thunbergii from Chinese ten major fritillaria-producing regions for the purpose of examining differences in element composition with region of origin and identifying elements’ importance to F. thunbergii. Analysis by inductively coupled plasma optical emission spectrometry allowed simultaneous determination of 18 elements in F. thunbergii (Al, B, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Na, Mn, Mo, S, Ni, P, Pb, and Zn), and patterns in element concentrations were deciphered by principle component analysis (PCA) and hierarchical cluster analysis (HCA). The element fingerprint was established which well reflected the element characteristics of F. thunbergii. Meanwhile, the ten regions were discriminated with 100% accuracy using HCA and PCA based on 18 of these elements. The element Mg, Ca, K, B, P, Mo, Na, Cd, Ni, and Al were viewed as the characteristic element of F. thunbergii, and the fingerprint of these elements could be used to distinguish the authenticity of F. thunbergii Miq.     

Fas- and Mitochondria-Mediated Signaling Pathway Involved in Osteoblast Apoptosis Induced by AlCl<Subscript>3</Subscript>

The concentrations of 13 elements (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, and Zn) were determined in several samples of native (wild) naturally growing and cultivated blueberry fruits. The total metal contents after mineralization were analyzed by inductively coupled plasma optical emission spectrometry. Reliability of the procedure was checked by the analysis of the certified reference materials Mixed Polish Herbs (INGT-MPH-2) and Leaves of Poplar (NCS DC 73350). In the fruits collected in the forest (wild blueberries), higher contents of Ca, Na, and Mg as well as Mn and Zn were observed. Similar levels of Cu, Cr, Fe, and Ni were detected in both wild-growing and cultivated plants. The significantly higher content of Fe and Cd in cultivated blueberries was connected with the content of these metals in soil samples collected from the same places. The metal extraction efficiency by hot water varied widely for the different blueberries (wild or cultivated) as well as their form (fresh or dried).     

Preparation of hair for measurement of elements by inductively coupled plasma-mass spectrometry (ICP-MS)

The preparation of hair for the determination of elements is a critical component of the analysis procedure. Open-beaker, closedvessel microwave, and flowthrough microwave digestion are methods that have been used for sample preparation and are discussed. A new digestion method for use with inductively coupled plasma-mass spectrometry (ICP-MS) has been developed. The method uses 0.2 g of hair and 3 mL of concentrated nitric acid in an atmospheric pressurelow-temperature microwave digestion (APLTMD) system. This preparation method is useful in handling a large numbers of samples per day and may be adapted to hair sample weights ranging from 0.08 to 0.3 g. After digestion, samples are analyzed by ICP-MS to determine the concentration of Li, Be, B, Na, Mg, Al, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, As, Se, Rb, Sr, Zr, Mo, Pd, Ag, Cd, Sn, Sb, I, Cs, Ba, Pt, Au, Hg, Tl, Pb, Bi, Th, and U. Benefits of the APLTMD include reduced contamination and sample handling, and increased precision, reliability, and sample throughput.     

Determination of major and trace elements in the liver of Wistar rats by inductively coupled plasma-atomic emission spectrometry and mass spectrometry

Inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES) were used to determine age-related changes in the concentrations of constituent elements in the livers of Wistar rats of 1 week to 12 months old. At first, sample preparation and analytical conditions were investigated in order to set up a simple routine procedure for measuring multiple elements simultaneously. Seventeen elements in the standard reference samples of bovine and pork livers as well as rat liver samples could be determined with a reasonable precision and reproducibility. They were P, K, Na, Fe, Mg, Ca, Zn, Rb, Cu, Mn, Mo, Al, Co, Sr, Cs, Pb, and Cd in order of the levels of concentration in the adult rat livers. Of these elements, the five major elements (P, K, Na, Fe, Mg, Ca) were determined with ICP-AES and the others with ICP-MS. Although the number of animals was too small to draw a statistically definite conclusion, it seems that age-related changes in the concentrations of these elements could be categorized into three general patterns: (1) remaining essentially constant throughout the animal ages, as observed for P, K, Na, Mg, Ca, Rb, Sr, Cs, and Pb, (2) increasing with age, as observed for Fe, Mn, Mo, Co, and Cd, and (3) decreasing with age, especially in the early stages of growth, as observed for Cu and Zn.     

Genetic aspects of the interrelation between alkaloids and chemical elements in Atropa belladonna L. and Glaucium flavum Grantz. plants

The variability of the contents of tropane and isoquinoline alkaloids, ashes, Na, K, Ca, Mg, Fe, Mn, Cu, Zn, Co, Mo, Cr, Al, Ba, V, Ni, Sr, Cd, Pb, J, and Ag was studied in individual plants of the industrial population of belladonna (Atropa belladonna L.) and yellow horned poppy (Glaucium flavum Crantz.). Numerous linear and nonlinear correlations of isoquinoline and tropane alkaloids with ashes and mineral elements were revealed by means of correlation and regression analyses. Alkaline earth elements (especially Sr and Ba) were shown to have a major role in the regulation of tropane alkaloid accumulation in belladonna leaves. K and Ni were of particular importance in the aerial part of yellow horned poppy. These elements at the suboptimal concentrations were most favorable for isoquinoline alkaloid accumulation in yellow horned poppy. Analytical mathematical models were derived for the regulation of alkaloid metabolism in test plants by some mineral elements (Ba, Mg, Al, Sr, Ni, Mn, and K). Our results indicate that the interrelation between alkaloids and elements in these plants is genetically determined.     

The concentrations of major and trace elements in rat kidney: Aging effects and mutual relationships

The concentrations of 26 major to trace elements in rat kidneys aging from 5 to 113 weeks old were determined. The rats investigated were the same rats used previously reported to have 29 elements in bones (femurs). The samples were decomposed by high purity nitric acid and hydrogen peroxide. Eight elements (Na, Mg, Si, P, K, Ca, Fe and Zn) were determined using inductively coupled plasma atomic emission spectrometry (ICP-AES) and 18 elements (Mn, Co, Ni, Cu, As, Se, Rb, Sr, Mo, Cd, Sn, Sb, Cs, Ba, Tl, Pb, Bi and U) were determined using inductively coupled plasma mass spectrometry (ICP-MS). The aging effects on the concentrations of these elements and mutual elemental relationships were investigated. Analysis of variance (ANOVA) for age variations indicated that the concentrations of P, K, Mn and Mo were almost constant across the age of rats (p > 0.3). The concentration of many elements such as Na, Mg, Ca, Fe, Co, Cu, Zn, As, Se, Cd, Sn, Sb, Tl, Pb and Bi, showed significant increasing trends (p < 0.01) with different patterns. Rubidium, Cs, Pb and Bi showed significant age variations but not monotonic trends. Silicon, Ni, Sr, Ba and U showed large concentration scatterings without any significant trends (p > 0.01). The metabolism of these elements may not be well established in the kidney. Many toxic elements such as As, Cd, Sn, Pb and Bi showed a narrow concentration range among age-matched rats. The kidney may have established metabolic mechanisms to confine or accumulate these toxic elements even though their concentrations are very low (e.g., 10 ng g^?1 of Cd). These elements also closely coupled with Fe. A cluster analysis was performed using an elemental correlation matrix and indicated that these elements, including Fe, formed a cluster. However, another cluster analysis using “an aging effect eliminated” elemental correlation showed different clustering in which the Fe, Cd cluster disappeared.