Fractionation of phosphorus and trace elements species in soybean flour and common white bean seeds by size exclusion chromatography-inductively coupled plasma mass spectrometry

Soluble species of phosphorus, sulfur, selenium and eight metals (Mn, Fe, Co, Ni, Cu, Zn, Mo and Cd) in soybean flour and common white bean seeds were investigated by size exclusion chromatography (SEC) and inductively coupled plasma mass spectrometry (ICP-MS). Samples were extracted by 0.02 mol l(-1) Tris-HCI buffer solution (pH 7.5). Fractionation of sample extracts by preparative scale SEC was accomplished using a Fractogel EMD BioSEC column (600 x 16 mm) and 0.02 mol l(-1) Tris-HCl buffer solution (pH 7.5) as mobile phase (flow rate: 2 ml min(-1)). A 2-ml sample was injected. Contents of elements in chromatographic fractions were determined by AAS, ICP-AES and ICP-MS. The elution profiles of P, Fe, Co, Ni, Cu, Zn and Mo in both samples were similar. Main species of Co, Ni, Cu, Zn and Mo were found in the low molecular weight region (2-5 kDa), whereas Fe is predominantly bound to high molecular weight compounds (180 kDa). The dominant phosphorus fraction was detected in the medium molecular weight region (10-30 kDa) and the other fraction in the low molecular weight region. Isotachophoretic analysis of chromatographic fractions revealed that the main phosphorus compound in the medium molecular weight region is phytic acid. SEC on Superdex 75 and Superdex Peptide columns (300 x 10 mm) was performed in on-line hyphenation with ICP-MS. The same mobile phase was used with a flow rate of 0.5 ml min(-1); volume of injected sample was 200 microl. Element specific chromatograms were obtained by continuous nebulization of effluent into ICP-mass spectrometer measuring intensities of 47(PO)+ and 48(SO)+ oxide ions and 55Mn, 57Fe, 59Co, 62Ni, 65Cu, 66Zn, 82Se, 95Mo and 114Cd nuclides. Chromatographic profiles of elements are generally analogous to those obtained with a Fractogel column, but better chromatographic resolution of separated species was achieved so that slight differences between samples were revealed. Estimated molecular weights of major phosphorus species in soybean flour and common white bean seed extracts are 6 and 3.6 kDa, respectively, whereas those of minor phosphorus species in both samples are 0.7 kDa. Traces of phosphorus were also detected in the high molecular weight region (130 kDa). Chromatograms of P, Ni, Cu, Zn and Mo compounds in both extracts are similar but not identical. Molecular weights of major Cu and Zn species are approximately 1 and 0.4 kDa for soybean flour and white bean seeds, respectively. In cases of Mn, Fe, Co and Se, the element profiles of soybean flour and white bean seed extracts are significantly different.     

高原鼢鼠和高原鼠兔骨骼无机化学成分的研究Ⅱ.必需微量元素

本文报道了高原鼢鼠和高原鼠兔整体骨骼及头骨、脊柱骨和下肢骨中Ｃｕ、Ｚｎ、Ｆｅ、Ｍｎ、Ｃｏ、Ｎｉ、Ｍｏ、Ｃｒ、Ｔｉ、Ｆ、Ｓｅ和Ｇｅ１２种必需微量元素的含量,并进行了显著性差异和相关性分析。结果表明：只有Ｃｕ的含量在两种动物骨骼中没有显著性差异（Ｐ＞０．０５）,其余１１种元素均有显著性或极显著性差异（Ｐ＜０．０５或Ｐ＜０．０１）,其中Ｚｎ、Ｆｅ、Ｍｎ、Ｃｏ、Ｎｉ、Ｍｏ、Ｆ和Ｓｅ的含量,高原鼢鼠＞高原鼠兔,而Ｃｒ、Ｔｉ和Ｇｅ的含量,高原鼠兔＞高原鼢鼠。微量元素在头骨、脊柱骨和下肢骨中分布很不均衡,以头骨的微量元素最为丰富     

Trace Elements in Fingernails of Healthy Chinese Centenarians

Trace element concentrations in body tissues of healthy centenarians have not been widely analyzed, yet they can be used as reference data leading to improved assessment of the aging process and monitoring of the micronutrient status of this age group. The present study sought to assess trace element concentrations and behaviors in the fingernails of healthy Chinese centenarians. The effects of gender on element concentrations, which also play an important role in determining the lifespan, were also investigated. Trace elements (Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Se, Sr, and Zn) in the fingernails of 78 healthy Chinese centenarians were determined by inductively coupled plasma mass spectrometry. The overall reference values obtained in milligram per kilogram are as follows: Ba, 5.10; Cd, 0.031; Co, 0.101; Cr, 0.82; Cu, 3.71; Fe, 154.35; Li, 0.31; Mn, 3.09; Mo, 0.040; Ni, 0.95; Pb, 1.86; Se, 0.44; Sr, 6.20; and Zn, 147.96. Data analysis showed that only Cr and Se concentrations show a normal distribution, and no significant difference between male and female groups was found for any element except Cr. Result also revealed that sufficient Se, Co, and Zn as well as lower or lack of exposure to Cr contribute positively to the lifespan of centenarians. The results suggest that regulating in vivo contents of trace elements, especially Se, Co, and Zn, is reasonable to intervene with geriatric diseases.     

Measurement of trace elements in proteins extracted from liver by size exclusion chromatography-inductively coupled plasma-mass spectrometry with a magnetic sector mass spectrometer

Proteins are extracted from liver into aqueous buffer at pH 7 and separated by size exclusion chromatography (SEC). Inductively coupled plasma mass spectrometry (ICP-MS) with a magnetic sector mass spectrometer is used to identify those protein fractions that contain Cu, Zn, Mn, Fe, Cd, S, P, Mo, Co, Ca, or Mg. The experimental setup provides very high sensitivity. Measurements at medium spectral resolution remove polyatomic interferences for some difficult elements like Fe, S, and P. Some elements are found in different molecular weight proteins; for example, cadmium binds to four different protein fractions (>400 kDa, 70 kDa, and metallothionein). Other elements like Mo, Ca, and Mg are present only in low-molecular-weight proteins or other small molecules.     

Accumulation of metals and metalloids in radish (Raphanus sativus L.) and spinach (Spinacea oleracea L.) irrigated with domestic wastewater in the peri-urban areas of Khushab City,Pakistan

Accumulation of different metals and metalloids was assessed in two vegetables radish (Raphanus sativus L.) and spinach (Spinacea oleracea L.) irrigated with domestic wastewater in the peri-urban areas of Khushab City, Pakistan. In general, the metal and metalloid concentrations in radish and spinach were higher at site-II treated with sewage water than those found at site-I treated with canal water. In case of radish at both sites the levels of metals (Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, and Pb) were below the permissible level except those of Mn, Ni, Mo, Cd, and Pb. At both sites, the transfer factor ranged from 0.047–228.3 mg kg^?1 with Cr having the highest transfer factor. The metal pollution index in soil was in the following order: As > Fe > Ni > Zn > Cd > Mo > Se > Co > Pb > Mn > Cr > Cu, respectively. While in case of spinach at both sites, the concentrations of metals and metalloids in vegetable samples irrigated with canal and sewage water were observed below the permissible level except Mn, Ni, Zn, Mo, and Pb. At both sites, the transfer factor ranged from 0.038–245.4 mg kg^?1 with Cr having the highest transfer factor. The metal pollution index in soil was in the following order: Cd > Ni > Co > Se > Mn > Zn > Mo > Pb > Fe > Cr > As > Cu, respectively.     

奉节脐橙不同器官元素含量分布特征

对奉节脐橙果、叶、干、根中的必需大量元素 (N、K、Ca、Mg、P、S)、微量元素 (Fe、Mn、Cu、Zn、B、Mo)、有益元素 (Si、Co、F、Se、Ni、Sr)、有毒有害元素 (Hg、As、Cr、Cd、Pb、Sb、Bi)的分布特征进行分析 ,结果表明 :果、叶、干、根对各元素的吸收与富集特征具有明显的规律性 ,如叶、干、根中大量元素含量次序均为 Ca>N>K>Mg,叶、干、根中微量元素含量均有 Fe>Mn>Zn>Cu>Mo的规律 ,根、干、叶中有益微量元素含量次序均为 Si>Sr>F>Ni>Co>Se,叶、干、根中有毒有害元素含量次序均有 Pb>As>Sb >Hg的规律 ;在脐橙各器官中 ,叶是大量元素与有毒有害元素最富集的器官 ,根则是有益元素最富集的器官 ,有毒有害元素的 Cr、微量元素的 Mn、Fe、Mo也以根最为富集 ,干则是上述元素最不富集的器官 ,所有元素中 ,仅 Zn在干中最富集 ;大量元素 (除 N外 )、微量元素、有益元素在脐橙各器官的分配含量与地壳土壤背景值的分异含量趋势基本一致 ,土壤背景是这三类元素的主要控制因素。但有毒有害元素的分配形式则明显受人类活动的影响     

Trace element composition of Ural licorice Glycyrrhiza uralensis Fisch. (Fabaceae Family)

The trace element composition of the subsurface (roots and rhizomes), overground (leaves and stems), and reproductive (bean valves) organs of Glycyrrhiza uralensis Fisch. was determined by synchrotron radiation X-ray fluorescence analysis (SRXFA). Concentrations of Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Y, Zr, Nb, Mo, Hg, Pb, Bi, Th, and U were measured. The data obtained were used to estimate the distribution of some elements in samples of various organs of licorice. Glycyrrhiza uralensis is an accumulator of Fe, Mn, Cu, and Co.     

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.     

Cumulative Author Index

Abstract

Bread represents an important source of trace elements in the human diet. This study is focused on home prepared bread in the Czech Republic. The amounts of Cu, Mo, Mn, Ni and Zn (total and soluble in Tris-HCl buffer, pH 7.5), Cd, Co, Fe, Pb and Tl (total only) as well as Hg (total and soluble in mercaptoethanol-HCl mixture) in raw materials and baked bread were determined using ICP-MS. Moreover, the speciation of elements was investigated using HPLC/ICP-MS. Isolated peptide ligands of the trace elements were analysed for amino acids and characterised by MALDI-MS. The concentrations of all elements were in accordance with Czech legislation. The solubility of the Ni species was not affected by the baking process, whereas the solubilities of Mo, Mn and Zn species decreased. Soluble mercury was found only in the inorganic form. The soluble species of Cu, Mo, Mn, Ni and Zn were found in two fractions with the apparent molecular weights of 1–2 kDa and 4–5 kDa. Ligands of trace metals isolated from these fractions contained appreciable amounts of Asx, Glx, Gly, Ser and Cys. No phytochelatin-like peptides were found in the MALDI-MS spectra of isolated ligands,. Using MALDI-MS/MS, the partial amino-acids sequences of peptide ligands were obtained, and the linkages of peptides and saccharides confirmed. The MS analysis of the trypsin digest of the medium molecular weight fraction revealed several proteins rich in cysteine (e.g., barwin and amylase inhibitors).     

Mineral content in the wild onion species and their nutritive value

The accumulation of 11 microelements (Fe, Zn, Cu, Co, Mn, Ni, Pb, Cd, Sr, Cr, and Se) by 7 wild onion species of the genus Allium was studied. A. flavescens Bess possesses the higher accumulating capability; it accumulates five of eleven microelements (Cr, Ni, Cu, Zn, and Se) with biological accumulation coefficient (BAC) exceeding 1 and also contains high levels of Fe, Co, and Mn. These features enable this species to be the most promising for the nutrition adjustment of human commons with above-mentioned microelements primarily with Cr, which content in 100 g onion leaves achieves 84% of commons. A. fistulosum L., A. odorum L., and broad-leaved A. nutans form specifically accumulate Cu, Zn, and Se. A. montanum Schmidt is characterized by the accumulation of Zn. A. angulosum and A. schoenoprasum are xharacterized by the accumulation of Se. The broad-leaved forms of A. schoenoprasum L., A. nutans L., and A. odorum L. compared with their narrow-leaved forms accumulate more amounts of Zn and Cu.     

Minor and trace elements in human milk from Guatemala,Hungary, Nigeria,Philippines, Sweden,and Zaire

Concentrations of As, Ca, Cd, Cl, Co, Cr, Cu, F, Fe, Hg, I, K, Mg, Mn, Mo, Na, Ni, P, Pb, Sb, Se, Sn, V, and Zn were determined in human whole milk samples from Guatemala, Hungary, Nigeria, Philippines, Sweden, and Zaire; in most of these countries, three groups of subjects representing different socioeconomic conditions were studied. Analytical quality control was a primary consideration throughout. The analytical techniques used were atomic absorption spectrophotometry, atomic emission spectrometry with an inductively coupled plasma, colorimetry, electrochemistry, using an ion-selective electrode and neutron activation analysis. The differences between median concentrations of Ca, Cl, Mg, K, Na, and P (minor elements) were lower than 20% among the six countries. Among trace elements, concentrations observed in Filipino milk for As, Cd, Co, Cr, Cu, F, Fe, Mn, Mo, Ni, Pb, Sb, Se, and V were higher than for milk samples from other countries. The remaining five countries showed a mixed picture of high and low values. In the case of at least some elements, such as, F, I, Hg, Mn, Pb, and Se, the environment appears to play a major role in determining their concentrations in human milk. The nutritional status of the mother, as reflected by her socioeconomic status, does not appear to influence significantly the breast milk concentrations of minor and trace elements. Significant differences exist between the actual daily intakes observed in this study and current dietary recommendations made by, for example, WHO and the US National Academy of Sciences. These differences are particularly large (an order of magnitude or more!) for Cr, F, Fe, Mn, and Mo; for other elements, such as, Ca, Cu, Mg, P, and Zn, they amount to at least a factor 2. In the opinion of the present authors, these findings point to the need for a possible reassessment of the dietary requirements of young infants with respect to minor and trace elements, particularly for the elements Ca, Cr, Cu, F, Fe, Mg, Mn, Mo, P, and Zn.     

The Dietary Acrylamide Intake Adversely Affects the Serum Trace Element Status

Acrylamide is an organic chemical which occurs in foods widespreadly consumed in diets worldwide. The purpose of this study was to evaluate the serum trace element levels (Fe, Cu, Zn, Mn, Cr, Se, Co, Ni, V, As, Mg, P, Li, K, Al) in Wistar rats exposed to acrylamide. Acrylamide was administered to the treatment groups at 2 and 5 mg/kg?body weight (bw)/day via drinking water for 90 days. Inductively coupled plasma mass spectrometry was used for the determination of serum trace element concentrations. Serum Zn, Se, Co, V and Mg concentrations of 5 mg/kg bw/day acrylamide-treated male rats were lower, whereas serum As concentration was higher than the same parameters of the controls rats. Similarly, serum Zn, Se, Co, V and Mg concentrations were decreased in 5 mg/kg?bw/day acrylamide-treated female rats compared with control rats. On the other hand, there were no significant differences between serum Fe, Cu, Mn, Cr, Ni, P, Li, K and Al concentrations of all groups. The results from this study provide evidence that dietary acrylamide intake adversely affects the serum trace elements status.     

背角无齿蚌对养殖池塘底泥释放重金属的净化效果

通过建立微型生态系统, 分析养殖池塘底泥释放重金属的特征及背角无齿蚌(Anodonta woodiana)对底泥释放重金属的净化效果。底泥对Al、Cr、Mn、Fe、Co、Ni、Cu、Zn、As、Mo和Pb的最大释放量分别为636、1.5、70.9、34951、10.3、36.9、34.0、53.2、72.4、48.8和3.0 μg·kg-1 dw; 蚌能够对Al、Cr、Mn、Co、Cu、Zn、As和Mo产生净化作用(P<0.05), 最大去除率分别可达到84.7%、98.0%、33.3%、14.3%、23.5%、69.4%、50.0%和13.0%, 响应面优化分析显示养殖密度和处理时间分别为40 只·m-3和24.49 d、25 只·m-3和23.96 d, Al和As去除率可提升至93.8%和60.5%; Al、Cr、Fe、Co、Cu、Zn、As和Mo的净化效果与养殖数量相关, Al、Cr、Mn、Fe、Co、Ni、Cu、Zn、As、Mo和Pb的净化效果与处理时间相关, Cr、Co、Ni、Cu和Zn的净化效果与两者交互作用相关(P<0.05)。提示背角无齿蚌有潜力防控池塘底泥重金属污染。     

Trace element studies on four species of Fusarium.

Trace element studies were carried out on four species of Fusarium: F. moniliforme, F. solani, F. poae and F. bulbigenum. Out of fifteen trace elements tested, Fe, Zn, Mn, Cu, Mo and B were found to be essential for growth and sporulation of all these species of Fusarium. Optimum concentrations in ppm of essential trace elements of these fungi were as follows: F. moniliforme Fe 1.0, Zn 0.1, Mn 0.1, Cu 0.1, Mo 0.1, B 1.0-10.0; F. solani Fe 1.0, Zn 10.0, Mn 0.1, Cu 0.01, Mo 1.0, B 0.1; F. poae Fe 1.0, Zn 0.1, Mn 0.1, Cu 1.0, Mo 0.1, B0.1, F. bulbigneum Fe 10.0, Zn 1.0, Mn 1.0, Cu 1.0, Mo 0.01, B 1.0. Concentrations higher than the optimum were inhibitory to the respective fungi.     

Interactions between toxic (As, Cd, Hg and Pb) and nutritional essential (Ca, Co, Cr, Cu, Fe, Mn, Mo, Ni, Se, Zn) elements in the tissues of cattle from NW Spain

Since the toxicity of one metal or metalloid can be dramatically modulated by the interaction with other toxic or essential metals, studies addressing the chemical interactions between trace elements are increasingly important. In this study correlations between the main toxic (As, Cd, Hg and Pb) and nutritional essential (Ca, Co, Cr, Cu, Fe, Mn, Mo, Ni, Se, Zn) elements were evaluated in the tissues (liver, kidney and muscle) of 120 cattle from NW Spain, using Spearman rank correlation analysis based on analytical data obtained by ICP-AES. Although accumulation of toxic elements in cattle in this study is very low and trace essential metals are generally within the adequate ranges, there were significant associations between toxic and essential metals. Cd was positively correlated with most of the essential metals in the kidney, and with Ca, Co and Zn in the liver. Pb was significantly correlated with Co and Cu in the liver. A large number of significant associations between essential metals were found in the different tissues, these correlations being very strong between Ca, Cu, Fe, Mn, Mo and Zn in the kidney. Co was moderately correlated with most of the essential metals in the liver. In general, interactions between trace elements in this study were similar to those found in polluted areas or in experimental studies in animals receiving diets containing high levels of toxic metals or inadequate levels of nutritional essential elements. These interactions probably indicate that mineral balance in the body is regulated by important homeostatic mechanisms in which toxic elements compete with the essential metals, even at low levels of metal exposure. The knowledge of these correlations may be essential to understand the kinetic interactions of metals and their implications in the trace metal metabolism.     

Studies on the Characteristic of Element Contents in the Dominant Plant Species of the Three gorges Region in China

The characteristics of the contents of 20 elements (Al, Fe, Mn, Ca, Mg, K, S, Si, P, Cd, Cu, Zn, Ti, Ni, Sr, Mo, Na, B, Cr, V) in 16 plant species collected from the Three Gorges Region in China were investigated. The average contents of Ca, K and Mg were higher than 1 000 μg·g-1, that of Al, P, Si, Fe, S and Mn ranged between 100—1 000 μg·g-1 and Ti, Cu, Ni, Cr, Mo, Cd and V were less than 10 μg·g- 1. The level of Na content was less than that of the reported. The main character of the element contents was of the Ca> K type. The contents of P, S, Ca and K in different plant samples showed a normal distribution pattern, while Al and Mn showed a elements lognormal distribution pattern. Plant species differed greatly in the element contents. On analyzing the coefficient of variation (C. V., % ), Al, Mn, Mg, Ni, Sr and Fe had higher C.V., while the C.V. of K, S, P, Cr, Cd and Cu was less than 60%, and Cu had the lowest C.V. The correlations between Al and Fe, Al and Ti, Al and Cr, A1 and V, Cd and Sr, Cd and Mo, Fe and V, Zn and Cr, Ni and Sr, Mg and Ni, Mo and Sr, Ca and Sr, Cr and Mo, Na and Mg, Na and P, P and S were statistically significant in different plant species. The classification of the 16 plant species and 20 dements by two-way indicator species analysis (TWINSPAN) method may suggest the difference in dement contents of the different plant species.     

Controlling Factors and Pollution Assessment of Potentially Toxic Elements in Topsoils of the Issyk-Kul Lake Region,Central Asia

The Issyk-Kul Lake region is well known for its magnificent scenery and unique scientific significance. With multivariable statistical methods, the contents of several geochemical elements (Fe, Mn, V, Zn, Cr, Co, Ni, Cu, As, Mo, Cd, Sb, Tl, Pb, and Hg) and total organic matter of 61 topsoil samples were analyzed, and then, the results were used to assess the environmental factors controlling the concentrations of potentially toxic elements (PTE) in the region. The results showed that most of the elements including Fe, Mn, V, Cr, Co, Ni, Cu, As, and Sb reflected the natural state, but several PTE (Zn, Mo, Hg, Cd, Pb, and Tl) had been influenced by anthropogenic factors. Among these, Zn, Mo, Hg, and Cd were significantly correlated with the organic matter content, which suggests that agricultural soils will accumulate more PTE. From the calculations for the human risk assessment of anthropogenically derived PTE (Zn, Mo, Hg, Cd, Pb, and Tl), the risks for ingestion in this region were found to be higher than those for inhalation and dermal absorption; however, the results also suggested there are no non-carcinogenic risks for all anthropogenically influenced PTE in the current state.     

Assessment of reference values for elements in human hair of urban schoolboys

Hair samples of youngsters (3–15 years of age) from several urban areas of Rome were analyzed to determine the content of 19 minor and trace elements with the aim of assessing Reference Values (RVs). Thirteen essential elements were taken into account, Ca, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, P, Se, V and Zn. On the other hand, Al, As, Cd, Pb, Sr and Ti were also evaluated on the basis of their potential toxicity. Procedures were developed for the collection, storage and pre-analytical treatment of samples. Measurements were performed by inductively coupled plasma atomic emission spectrometry. Subgroups were formed according to age and sex. Significant differences were found for certain elements depending on age and sex. This was the case, e.g., for Ca which showed a mean value of 336 mg/kg for males and of 537 mg/kg for females. The sex-dependent pattern for this element was also apparent when the three age subgroups of 3–6, 7–10 and 11–15 years were compared. The overall RVs obtained (mg/kg) are as follows Al, 10.2; As, 0.09; Ca, 450; Cd, 0.23; Co, 0.67; Cr, 0.99; Cu, 22.1; Fe, 19.0; Mg, 28.0; Mn, 0.35; Mo, 0.43; Ni, 1.49; P, 195; Pb, 7.11; Se, 0.77; Sr, 1.20; Ti, 0.79; V, 1.22; and Zn 150.     

Mineral Composition of Wild Onions and Their Nutritional Value

Leaf accumulation of 11 microelements (Fe, Zn, Cu, Co, Mn, Ni, Pb, Cd, Sr, Cr, and Se) was studied in seven wild onion species of the genus Allium. A. flavescens Bess. accumulates five microelements (Cr, Ni, Cu, Zn, and Se) and also contains Fe, Co, and Mn at high concentrations. These features underlie the significant promise of this species as a means of procurement (nutritional adjustment of the content) of these microelements. The content of Cr in 100 g of leaves of this species is equivalent to 84% of the daily human need for this microelement. A. fistulosum L., A. odorum L., and the broad-leaved form of A. nutans specifically accumulate Cu, Zn, and Se. A. montanum Schmidt. is characterized by the accumulation of Zn. A. angulosum L. and A. schoenoprasum L. are characterized by the accumulation of Se. The broad-leaved forms of A. schoenoprasum L., A. nutans L., and A. odorum L. accumulate higher amounts of Zn and Cu than their narrow-leaved counterparts.     

Trace elements in human milk: Correlation with blood levels, inter-element correlations and changes in concentration during the first month of lactation

Using inductively coupled plasma mass spectrometry (ICP-MS) based analytical procedures, the concentration of several trace elements (Mn, As, Pb, Co, Ni, Cu, Zn and Se) was determined in human milk samples collected from a group of healthy lactating Portuguese women (n=44), both on the 2nd day postpartum (i.e., colostrum; n=34) and at 1 month postpartum (i.e., mature milk; n=19). Blood samples (n=44), collected on the 2nd day after parturition, were also analyzed for the same trace elements. No major correlations were observed between the levels of the analyzed trace elements in blood and colostrum samples. All the studied elements, except for Co, Pb and Ni, showed a significant trend for a decrease in concentration in milk during the first month of lactation. This trend was more pronounced for Zn and Se, whose levels decreased to approximately 23% and 44% of their initial mean concentration, respectively. With the exception of Co (r=0.607) and Zn (r=0.487), no significant correlations were observed when comparing the levels of each trace element between samples of colostrum and mature milk. Several inter-element correlations were found within each type of milk sample. The most significant were: (i) Se vs Cu (r=0.828) and Se vs Co (r=0.605) in colostrum samples and (ii) Ni vs Pb (r=0.756), Ni vs Mn (r=0.743) and Se vs Co (r=0.714) in mature milk samples. An inverse correlation between Zn and Se was also found in both types of milk sample; however, it only reached statistical significance for mature milk (r=-0.624).