The Simultaneous Analysis of Eight Essential Trace Elements in Human Milk by ICP-MS

Determination of the Elemental Iodine in Human Breast Milk by Inductively Coupled Plasma mass Spectrometry

Adequate iodine status in lactating women is defined by a maternal median urinary iodine concentration (UIC) ≧ 100 µg/L. However, the above-mentioned criterion does not account for the secretion of iodine into breast milk and could not truly reflect the amount of iodine delivered to the infants. Measuring breast milk median iodine concentration (BMIC) is crucial, but the method to measure BMIC has not been developed and validated in Taiwan. We adopted the ammonia dilution method without prior sample digestion to measure BMIC by inductively coupled plasma mass spectrometry (ICP-MS). Samples and iodate calibrators were prepared into an aqueous solution containing Triton X-100, 0.5% ammonia solution, and tellurium (128Te) as the internal standard. Precision, accuracy, serial dilution, and recovery tests were performed for method validation. The range of intra-assay and inter-assay coefficient of variation for the four human breast milk samples with different iodine concentrations were 3.2-4.7% and 2.3-5.5%, respectively. The standard NIST 1549 milk powder was prepared into three different concentrations of 50 µg/L, 100 µg/L, and 200 µg/L to assess the accuracy; the bias was < 5%. A recovery of 95-105% was achieved for four human breast milk samples spiked with sodium iodide solution. The serial dilution test confirmed linearity up to 0.998. The limit for detection and quantification was 0.78 µg/L and 2.34 µg/L, respectively. The results of the current study confirmed that this ICP-MS method is accurate and reliable in measuring BMIC.

Evaluating human milk as a drug delivery vehicle for clofazimine to premature infants

Human milk is proposed as a drug delivery vehicle suitable for use in neonatal patients. Clofazimine, traditionally used for the treatment of leprosy and tuberculosis, is emerging as a treatment for cryptosporidiosis in infants, however its poor aqueous solubility has led to its commercial formulation as a waxy lipid formulation in a capsule, a format that is not suitable for infants. In this study, the evaluation of pasteurised human milk for the delivery of clofazimine was investigated using an in vitro lipolysis model to simulate gastric and intestinal digestion. The total lipid composition of the human milk was characterised alongside the liberated fatty acid species following digestion for comparison to alternative lipid-based delivery systems. Small-angle X-ray scattering was used to measure the presence of crystalline clofazimine during digestion and hence the extent of drug solubilisation. High-performance liquid chromatography was used to quantify the mass of clofazimine solubilised per gram of human milk fat (drug-to-fat ratio) in digested and undigested human milk. The digestion process was essential for the solubilisation of clofazimine, with digested human milk solubilising a sufficient dose of clofazimine for treatment of a premature infant. Human milk solubilised the clofazimine to a greater extent than bovine milk and infant formula during digestion, most likely as a result of differing lipid composition and increased long-chain fatty acid concentrations. These findings show that human milk enhances the solubility of clofazimine as a model drug and may be a suitable drug delivery vehicle for infant populations requiring therapeutic treatment.

Facets of ICP-MS and their potential in the medical sciences-Part 1: fundamentals, stand-alone and hyphenated techniques

Since its inception in the early 80s, inductively coupled plasma–mass spectrometry has developed to the method of choice for the analysis of elements in complex biological systems. High sensitivity paired with isotopic selectivity and a vast dynamic range endorsed ICP-MS for the inquiry of metals in the context of biomedical questions. In a stand-alone configuration, it has optimal qualities for the biomonitoring of major, trace and toxicologically relevant elements and may further be employed for the characterisation of disrupted metabolic pathways in the context of diverse pathologies. The on-line coupling to laser ablation (LA) and chromatography expanded the scope and application range of ICP-MS and set benchmarks for accurate and quantitative speciation analysis and element bioimaging. Furthermore, isotopic analysis provided new avenues to reveal an altered metabolism, for the application of tracers and for calibration approaches. In the last two decades, the scope of ICP-MS was further expanded and inspired by the introduction of new instrumentation and methodologies including novel and improved hardware as well as immunochemical methods. These additions caused a paradigm shift for the biomedical application of ICP-MS and its impact in the medical sciences and enabled the analysis of individual cells, their microenvironment, nanomaterials considered for medical applications, analysis of biomolecules and the design of novel bioassays. These new facets are gradually recognised in the medical communities and several clinical trials are underway. Altogether, ICP-MS emerged as an extremely versatile technique with a vast potential to provide novel insights and complementary perspectives and to push the limits in the medical disciplines. This review will introduce the different facets of ICP-MS and will be divided into two parts. The first part will cover instrumental basics, technological advances, and fundamental considerations as well as traditional and current applications of ICP-MS and its hyphenated techniques in the context of biomonitoring, bioimaging and elemental speciation. The second part will build on this fundament and describe more recent directions with an emphasis on nanomedicine, immunochemistry, mass cytometry and novel bioassays.

Enhanced Growth Inhibition and Apoptosis Induction in Human Colon Carcinoma HT-29 Cells of Soluble Longan Polysaccharides with a Covalent Chemical Selenylation

The selenylated polysaccharides chemically belong to the organic Se-conjugated macromolecules and have recently been attracting more and more attention due to their potential to promote body health or prevent cancers. Longan (Dimocarpus longan L.), as a subtropical fruit, contains soluble and non-digestible polysaccharides that are regarded with health care functions in the body. In this study, the longan polysaccharides (LP) were obtained via enzyme-assisted water extraction, and then chemically selenylated using a reaction system composed of HNO₃–Na₂SeO₃ to yield two selenylated products, namely, SeLP1 and SeLP2, with Se contents of 1.46 and 4.79 g/kg, respectively. The anti-cancer effects of the three polysaccharide samples (LP, SeLP1, and SeLP2) were thus investigated using the human colon cancer HT-29 cells as the cell model. The results showed that SeLP1 and SeLP2 were more able than LP to inhibit cell growth, alter cell morphology, cause mitochondrial membrane potential loss, increase intracellular reactive oxygen and [Ca²⁺]_i levels, and induce apoptosis via regulating the eight apoptosis-related genes and proteins including Bax, caspases-3/-8/-9, CHOP, cytochrome c, DR5, and Bcl-2. It was thereby proven that the selenylated polysaccharides could induce cell apoptosis via activating the death receptor, mitochondrial-dependent, and ER stress pathways. Collectively, both SeLP1 and SeLP2 showed higher activities than LP in HT-29 cells, while SeLP2 was consistently more active than SeLP1 in exerting these assessed anti-cancer effects on the cells. In conclusion, this chemical selenylation covalently introduced Se into the polysaccharide molecules and caused an enhancement in their anti-cancer functions in the cells, while higher selenylation extent was beneficial to the activity enhancement of the selenylated products.

Activities of the soluble and non-digestible longan (Dimocarpus longan Lour.) polysaccharides against HCT-116 cells as affected by a chemical selenylation

The soluble and non-digestible longan (Dimocarpus longan Lour.) polysaccharides (LP) with Se content less than 0.01 g/kg were extracted and selenylated chemically with the HNO₃–Na₂SeO₃ system, to prepare two selenylated products namely SeLP1 and SeLP2 with enhanced Se contents of 1.46 and 4.79 g/kg, respectively. LP, SeLP1, and SeLP2 were then measured and compared for their saccharide features and bioactivity in human colon carcinoma HCT-116 cells. Compared with LP, both SeLP1 and SeLP2 contained more neutral saccharides, but showed reduced uronic acid content and undetectable sulfate. Moreover, SeLP1 and especially SeLP2 in the cells showed higher activities than LP, reflected by their enhanced capacity to inhibit cell growth, alter cell morphology, and suppress cell colony formation. Compared with LP, SeLP1 and especially SeLP2 were also more capable of promoting intracellular reactive oxygen species and Ca²⁺ levels, causing mitochondrial membrane potential loss, or inducing cell apoptosis via up- and down-regulating the eight apoptosis-related genes and proteins. Overall, the performed chemical selenylation of LP resulted in obvious changes in these saccharide features and simultaneously enhanced the anti-cancer activity of the selenylated products against the cells clearly, while a higher selenylation extent of the selenylated products consistently caused higher activity towards the cells. The results of this study thus highlighted that this chemical selenylation is applicable when aiming to enhance the bioactivities of natural polysaccharides.

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Chemical selenylation of longan polysaccharides causes Se conjugation covalently.

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The selenylated polysaccharides have changes in saccharide features and sulfate.

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The selenylated polysaccharides have higher activities to HCT-116 cells.

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Higher polysaccharide selenylation consistently leads to activity increase in cells.

Levels of Trace Elements in Human Breast Milk in Jordan: a Comparison with Infant Formula Milk Powder

Human breast milk and infant formula milk powder (IFMP) are the main nutritional sources for infants. In the literature, there is a lack of studies concerning levels of trace elements in human milk and IMP in Jordan. The aim of this research was the determination of levels of 24 trace elements in human breast milk from Jordanian mothers (n = 76) and IFMP from Jordanian market (n = 22). Elements were classified to essential (Mg, Fe, Zn, Cu, Mn, Ni, Cr, Mo, Co, and Se), non-essential (Al, Ag, Ba, Bi, Cs, Ga, Li, Rb, Sr, U, and V), and potentially toxic (As, Cd, and Pb). Inductively coupled plasma-mass spectrometry (ICP-MS) following a microwave digestion of samples with concentrated nitric acid and hydrogen peroxide was performed. Our results featured levels of each targeted element in human milk and IFMP (mean, standard deviation (SD), median, and range). Statistical analysis included a one-way analysis of variance (ANOVA), and Pearson's correlations. A sample toxicological analysis study for toxic elements As, Cd, and Pb was performed, and results were inspected. Levels of most elements including toxic elements are larger than in human milk samples, and comparable to in IFPMs to literature results. Mean levels of majority of the elements (17 out of 24) in human milk were significantly different than respective means in IFMP solutions. Positive correlation was observed between total toxic elements and Al, Cu, and Fe in human milk samples. Results of toxicological analysis demonstrated that most of IFMP samples do not represent a health hazard to infants regarding As, Cd, and Pb. The same applies for Cd in human milk samples. However, levels of As and Pb in 70% of human milk samples exceed the provisional tolerable weekly intake (PTWI) for As and Pb.

Current applications and future perspectives on elemental analysis of non-invasive samples for human biomonitoring

Humans are continuously exposed to numerous environmental pollutants including potentially toxic elements. Essential elements play an important role in human health. Abnormal elemental levels in the body, in different forms that existed, have been reported to be correlated with different diseases and environmental exposure. Blood is the conventional biological sample used in human biomonitoring. However, blood samples can only reflect short-term exposure and require invasive sampling, which poses infection risk to individuals. In recent years, the number of research evaluating the effectiveness of non-invasive samples (hair, nails, urine, meconium, breast milk, placenta, cord blood, saliva and teeth) for human biomonitoring is increasing. These samples can be collected easily and provide extra information in addition to blood analysis. Yet, the correlation between the elemental concentration in non-invasive samples and in blood is not well established, which hinders the application of those samples in routine human biomonitoring. This review aims at providing a fundamental overview of analytical methods of non-invasive samples in human biomonitoring. The content covers the sample collection and pretreatment, sample preparation and instrumental analysis. The technical discussions are separated into solution analysis and solid analysis. In the last section, the authors highlight some of the perspectives on the future of elemental analysis in human biomonitoring.

Human Milk Concentrations of Minerals, Essential and Toxic Trace Elements and Association with Selective Medical, Social, Demographic and Environmental Factors

This study aims to quantify concentrations of minerals and trace elements in human milk (HM) and infant formula (IF) and evaluate associations with medical, social, environmental, and demographic variables. A prospective, case series study of 170 nursing mothers was made. HM samples were obtained from full-term (colostrum, intermediate and mature HM) and preterm (mature HM) mothers. Variables of interest were assessed by a questionnaire. For comparison, IF samples (n = 30) were analyzed in a cross-sectional study. Concentrations of 35 minerals, essential and toxic trace elements were quantified, 5 for the first time: thallium in HM and IF; strontium in preterm HM; and gallium, lithium and uranium in IF. In preterm and full-term HM, levels of selenium (p < 0.001) were significantly lower than recommended and were associated with low birth weight (p < 0.002). Cesium and strontium concentrations were significantly higher than recommended (p < 0.001). Associations were observed between arsenic and residence in an urban area (p = 0.013), and between lead and smoking (p = 0.024) and well-water consumption (p = 0.046). In IF, aluminum, vanadium, and uranium levels were higher than in HM (p < 0.001); uranium, quantified for the first time, was 100 times higher in all types of IF than in HM. Our results indicate that concentrations of most trace elements were within internationally accepted ranges for HM and IF. However, preterm infants are at increased risk of nutritional deficiencies and toxicity. IF manufacturers should reduce the content of toxic trace elements.

Relationship between heavy metals and alpha emission rates in breast milk and blood of women

BACKGROUND

The current study determines the relationship between heavy metals and alpha particles emission rates in milk and blood of lactating women in Diwanyah, Iraq.

METHODS

Heavy metals and alpha particle emission rates have been measured using an Atomic Absorption Spectrophotometer and a Nuclear Track Detector.

RESULTS

The results show that Pb, Cd, and Cu in milk are 0.2239 ± 0.0007 ppm, 0.0156 ± 0.0001 ppm, and 0.1811 ± 0.0006 ppm, respectively. Pb, Cd, and Cu in the blood were 0.0898 ± 0.0008 ppm, 0.0432 ± 0.0010 ppm, and 0.1729 ± 0.0004 ppm, respectively. The highest alpha particle emission rate was found to be in age interval from 23 y to 28 y in milk, while the highest alpha particle emission rate was found to be in the age interval from 35 y to 40 y.

CONCLUSIONS

This study concludes that no statistical significance between Pb, Cd, Cu and Eα in milk and blood at level 0.01. The following order of bioavailability was found with heavy metals Cu < Pb < Cd.

Total metal content and chemical speciation analysis of iron, copper, zinc and iodine in human breast milk using high-performance liquid chromatography separation and inductively coupled plasma mass spectrometry detection

The aim of this research was to quantify essential trace elements (iron, copper, zinc and iodine) and establish their speciation in human milk. Both the element and the species are important in new-born nutrition. Colostrum, and transitional and mature milks (25) were collected from 18 mothers of pre-term or full-term infants. Concentrations of the target elements were determined using ICP-MS. For speciation, HPLC coupled to ICP-MS was employed. Total contents of the micronutrients varied in mothers of pre-term (Fe = 0.997, Cu = 0.506, Zn = 4.15 and I = 0.458 mg L^-1) and mothers of full-term (Fe = 0.733, Cu = 0.234, Zn = 2.91 and I = 0.255 mg L^-1) infants. Fe, Cu and Zn were associated with biomolecules with high molecular mass compounds, such as immunoglobulins, albumin and lactoferrin whilst iodine was only found as iodide.

Diagnostic Value of Energy Dispersive Hand-Held X-ray Fluorescence Spectrometry in Determining Trace Element Concentrations in Ovine Liver

There are no data available on the use of hand-held X-ray fluorescence (XRF) spectrometry to determine trace element concentrations in veterinary diagnostics. The hand-held XRF spectrometer is easy to use and does not require extensive training for the operator. In Sub-Saharan Africa with few centralised analytical laboratories equipped with expensive apparatus or mass spectrometry capabilities, trace element analysis using the hand-held XRF spectrometer provides an alternative. The objective of this study was to compare ovine hepatic copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), selenium (Se) and zinc (Zn) concentrations as obtained with the hand-held XRF spectrometer to those of a reference laboratory using inductively coupled plasma mass spectrometry (ICP-MS). Thirty ovine livers were obtained from an abattoir; prepared as wet blended and oven-dried samples and analysed. Bayesian correlation was used to assess the correspondence between results from the XRF and ICP-MS analyses. The oven-dried preparation procedure for XRF provided the best correlation with the ICP-MS data. The correlations for Cu and Zn were strong and the XRF method may represent a suitable substitute for ICP-MS analysis. For Mn and Fe the correlations were moderately strong and the XRF method may be suitable. For Mo, the correlation was weak and XRF cannot be recommended. Selenium could not be detected in samples prepared by either method. Hand-held XRF spectrometry was a practical method to determine liver concentrations of specific trace elements under African conditions and may significantly reduce the turn-around time of analysis, but unfortunately the apparatus is expensive.

Effects of dietary supplementation with Pediococcus acidilactici ZPA017 on reproductive performance, fecal microbial flora and serum indices in sows during late gestation and lactation

Objective

To investigate the effects of low-dose trace mineral proteinates on reproductive performance, mineral status, milk immunoglobulin contents and fecal mineral excretion of sows.

Methods

Eighty crossbred sows (Landrace×Large White) were randomly allocated to two groups in a 135-day trail, from breeding through 21 d postpartum. The two treatments were inorganic trace minerals (ITM): a basal diet+inorganic iron (Fe), copper (Cu), manganese (Mn), and zinc (Zn) at 90, 15, 25 and 90 mg/kg, respectively and organic trace minerals (OTM): a basal diet+proteinates of Fe, Cu, Mn, and Zn at 72, 12, 20, and 72 mg/kg, respectively.

Results

Compared with ITM, OTM significantly increased (p<0.05) the number of piglets with birthweight >1 kg, the litter weaning weight, and milk Fe, Cu contents. No significant differences (p>0.05) were observed on sow hair mineral contents or immunoglobulin M (IgM), IgG, and IgA contents in colostrum and milk. In comparsion to ITM, OTM decreased fecal Fe, Cu, Mn, and Zn contents of gestating sows (p<0.01) and Fe, Mn, and Zn in lactating sows (p<0.01).

Conclusion

These results indicate that low-dose mineral proteinates can increase the number of piglets with birthweight >1 kg, the litter weaning weight and certain milk mineral concentrations while reducing fecal mineral excretion.

Quantification of 71 detected elements from Li to U for aqueous samples by simultaneous-inductively coupled plasma-mass spectrometry

Quantitative analysis of multi-element concentrations in aqueous solutions, such as water, beverages and biofluids, has long been performed by sequential inductively coupled plasma-mass spectrometry. Recently, a fully simultaneous mass spectrum monitoring ICP-MS instrument that fits a compact Mattauch–Herzog geometry (MH-ICP-MS) with a permanent magnet and a large, spatially resolving semiconductor ion detector has been introduced. This technology allows coverage of the complete inorganic relevant mass range from ⁶Li to ²³⁸U in a single measurement, which helps to mitigate the restriction on the number of inorganic elements whose concentrations may be routinely measured from one sample, thus reducing operational assay times and aqueous sample volumes for evaluations across the breadth of the periodic table. We report here on a detailed method for utilizing MH-ICP-MS to detect all elements of the relevant inorganic spectrum in aqueous samples; 7 types of water, 4 types of beverage, and 4 biofluid biological samples. With this method 71 elements can be routinely detected simultaneously in seconds and in as little as 1–4 mL sample, when using a specific set of calibration and internal standards. Quantitative results reveal distinct element patterns between each sample and within types of samples, suggesting that different types of aqueous solutions can be recognized and distinguished by their elemental patterns. The method has implications for understanding elemental distribution and concentration for many fields, including nutrition, studies of the biosphere, ecological stoichiometry, and environmental health fields, among others, where broad elemental information is actually required.

Quantitative analyses of multi-element concentrations in aqueous solutions, such as water, beverages and biofluids, are performed by simultaneous MH-ICP-MS.

Validation of a dilute and shoot method for quantification of 12 elements by inductively coupled plasma tandem mass spectrometry in human milk and in cow milk preparations

Nutritional information about human milk is essential as early human growth and development have been closely linked to the status and requirements of several macro- and micro-elements. However, methods addressing whole mineral profiling in human milk have been scarce due in part to their technical complexities to accurately and simultaneously measure the concentration of micro- and macro-trace elements in low volume of human milk. In the present study, a single laboratory validation has been performed using a "dilute and shoot" approach for the quantification of sodium (Na), magnesium (Mg), phosphorus (P), potassium (K), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), selenium (Se), molybdenum (Mo) and iodine (I), in both human milk and milk preparations. Performances in terms of limits of detection and quantification, of repeatability, reproducibility and trueness have been assessed and verified using various reference or certified materials. For certified human milk sample (NIST 1953), recoveries obtained for reference or spiked values are ranged from 93% to 108% (except for Mn at 151%). This robust method using new technology ICP-MS/MS without high pressure digestion is adapted to both routinely and rapidly analyze human milk micro-sample (i.e. less than 250 μL) in the frame of clinical trials but also to be extended to the mineral profiling of milk preparations like infant formula and adult nutritionals.

Integrated three-electrode screen-printed sensor modified with bismuth film for voltammetric determination of thallium(I) at the ultratrace level

In the present paper, for the first time, the integrated three-electrode screen-printed sensor with in situ plated bismuth film carbon working electrode was applied for the ultratrace determination of thallium(I) (Tl(I)). Under optimized conditions extremely low limits of detection were reached, 8.47 × 10^-10 and 6.71 × 10^-12 mol L^-1 for the deposition times of 60 s and 300 s, respectively. The influences of foreign metal ions and surfactants on the voltammetric signal of thallium in natural samples were minimized using 1 × 10^-5 mol L^-1 EDTA and Amberlite XAD-7 resin added to the buffer solution (CH₃COONH₄, CH₃COOH and NH₄Cl) of pH = 4.6 ± 0.1. The developed voltammetric method with integrated three-electrode screen-printed sensor was validated with use of certified reference materials (surface, rain and natural water) and can be in future applied to field analyses of Tl(I).

Analyses of Essential Elements and Heavy Metals by Using ICP-MS in Maternal Breast Milk from Şanlıurfa, Turkey

Maternal breast milk is a unique biological matrix that contains essential micronutrients. Potentially heavy metals may also affect infants' health and growth through maternal breast milk. The purpose of this study was to determine and compare the essential elements and heavy metals of maternal breast milk of nursery mothers residing in Şanlıurfa province, Turkey. Maternal breast milk concentrations of sodium, magnesium, phosphorus, potassium, calcium, iron, copper, zinc, arsenic, and lead were analyzed in a random sample of the first time in urban and suburban nursery Turkish mothers (n: 42). Eight essential elements and two heavy metals were analyzed using ICP-MS after microwave digestion. For bivariate analyses of variables, we use nonparametric Spearman's correlation coefficient test. The mean concentrations of essential elements and heavy metals were as follows: sodium 330 ± 417 mg/L, magnesium 32.6 ± 15.5 mg/L, phosphorus 156 ± 46.2 mg/L, potassium 488 ± 146 mg/L, calcium 193 ± 53.2 mg/L, iron 1.65 ± 1.43 mg/L, copper 0.54 ± 0.46 mg/L, zinc 2.89 ± 3.23 mg/L, arsenic < 1 μg/L, and lead < 1 μg/L. Concentrations of heavy metals in maternal breast milk may have the important implication that it is not affected by environmental pollution in this province. This study provides reliable information about maternal breast milk concentrations of nursery mothers residing in Şanlıurfa, Turkey, and also compares the relations between essential elements and socioeconomic conditions, residing areas, and using copper equipment for food preparation of which some have not previously been reported.

Concentrations of trace elements in human milk: Comparisons among women in Argentina, Namibia, Poland, and the United States

Human milk contains essential micronutrients for growth and development during early life. Environmental pollutants, such as potentially toxic metals, can also be transferred to the infant through human milk. These elements have been well-studied, but changing diets and environments and advances in laboratory technology require re-examining these elements in a variety of settings. The aim of this study was to characterize the concentrations of essential and toxic metals in human milk from four diverse populations. Human milk samples (n = 70) were collected in Argentina (n = 21), Namibia (n = 6), Poland (n = 23), and the United States (n = 20) using a standardized mid-feed collection procedure. Milk concentrations of calcium, zinc, iron, copper, manganese, lead, arsenic, and cadmium were determined using inductively coupled plasma mass spectrometry (ICP-MS). We used standard multiple linear regression models to evaluate differences among populations, while including infant age, infant sex, and maternal parity status (multiparous or primiparous) as covariates. Concentrations of all elements, except zinc, varied across populations after controlling for infant age, infant sex, and maternal parity. Calcium and magnesium showed more differences across populations than iron or copper. There were no significant differences among population in zinc concentrations. Mean concentrations of lead, but not arsenic, were low compared to recently published values from other populations. The concentrations of trace elements in human milk are variable among populations. Limitations due to small sample sizes and environmental contamination of some samples prevent us from drawing robust conclusions about the causes of these differences.

Flow of essential elements in subcellular fractions during oxidative stress

Essential trace elements are commonly found in altered concentrations in the brains of patients with neurodegenerative diseases. Many studies in trace metal determination and quantification are conducted in tissue, cell culture or whole brain. In the present investigation, we determined by ICP-MS Fe, Cu, Zn, Ca, Se, Co, Cr, Mg, and Mn in organelles (mitochondria, nuclei) and whole motor neuron cell cultured in vitro. We performed experiments using two ways to access oxidative stress: cell treatments with H₂O₂ or Aβ-42 peptide in its oligomeric form. Both treatments caused accumulation of markers of oxidative stress, such as oxidized proteins and lipids, and alteration in DNA. Regarding trace elements, cells treated with H₂O₂ showed higher levels of Zn and lower levels of Ca in nuclei when compared to control cells with no oxidative treatments. On the other hand, cells treated with Aβ-42 peptide in its oligomeric form showed higher levels of Mg, Ca, Fe and Zn in nuclei when compared to control cells. These differences showed that metal flux in cell organelles during an intrinsic external oxidative condition (H₂O₂ treatment) are different from an intrinsic external neurodegenerative treatment.

The effect of pasteurization on trace elements in donor breast milk

OBJECTIVE

Premature infants often receive pasteurized donor human milk when mothers are unable to provide their own milk. This study aims to establish the effect of the pasteurization process on a range of trace elements in donor milk.

STUDY DESIGN

Breast milk was collected from 16 mothers donating to the milk bank at the Royal Brisbane and Women's Hospital. Samples were divided into pre- and post-pasteurization aliquots and were Holder pasteurized. Inductively coupled plasma mass spectrometry was used to analyze the trace elements zinc (Zn), copper (Cu), selenium (Se), manganese (Mn), iodine (I), iron (Fe), molybdenum (Mo) and bromine (Br). Differences in trace elements pre- and post-pasteurization were analyzed.

RESULTS

No significant differences were found between the trace elements tested pre- and post-pasteurization, except for Fe (P<0.05). The median (interquartile range, 25 to 75%; μg l(-1)) of trace elements for pre- and post- pasteurization aliquots were-Zn: 1639 (888-4508), 1743 (878-4143), Cu: 360 (258-571), 367 (253-531), Se: 12.34 (11.73-17.60), 12.62 (11.94-16.64), Mn: (1.48 (1.01-1.75), 1.49 (1.11-1.75), I (153 (94-189), 158 (93-183), Fe (211 (171-277), 194 (153-253), Mo (1.46 (0.37-2.99), 1.42 (0.29-3.73) and Br (1066 (834-1443), 989 (902-1396).

CONCLUSIONS

Pasteurization had minimal effect on several trace elements in donor breast milk but high levels of inter-donor variability of trace elements were observed. The observed decrease in the iron content of pasteurized donor milk is, however, unlikely to be clinically relevant.