The Assessment of Reference Values for Elements in Human Biological Tissues and Fluids: A Systematic Review

Thiol-functionalized MOF modified 3D printed monolithic microextraction array for analysis of trace Cd and Pb in human urine

Controlling the position, size, and shape of pores is a limitation of traditional monolithic preparation methods. The application of 3D printing technology offers high customizability, allowing the precise printing of pore positions, sizes, and shapes according to the designer's 3D model. Herein, by using Projection Microstereolithography (PμSL), we prepared a 3D-printed monolithic array with post-modification of thiol-functionalized metal-organic framework (MOF), and combined it with inductively coupled plasma mass spectrometry (ICP-MS) for the online analysis of trace Cd and Pb in human urine. To achieve array monolithic microextraction, six 3D-printed monolithic columns were modified with thiol-functionalized MOF-808 (MOF-808-SH), and were then assembled in the 3D printed extraction device incorporating gas valve and scaffold. The MOF-808-SH modified 3D-printed monolithic column exhibits excellent extraction performance to Cd2+ and Pb2+ due to rich active adsorption sites and hierarchical porous structure, and has long life span (>100 reused times). Under the optimized conditions, the limits of detection (LODs) are 3.5 and 17.6 ng L-1 for Cd2+ and Pb2+, respectively, with the relative standard deviations of 4.9 % and 8.2 % (0.1 μg L-1, n = 7), and the sample throughput is 11 h-1. To validate the accuracy of the method, the method was used to determine Cd and Pb in Certified Reference Materials of freeze-dried human urine, the determined results agree well with the certified values. This method was also successfully applied to the determination of trace Cd and Pb in real human urine samples. The developed method offers low LODs, robust anti-interference capability, high sample throughput, long reuse cycles, and automation analysis, showing great potential for the analysis of trace heavy metals in biological samples.

A Fluorometric Method for Zinc Estimation: Applications in the Estimation of Plasma Zinc and in Assessing Zinc Bioaccessibility from Rice

Sensitive and precise methods for the estimation of zinc (Zn) in biological fluids and foods are important tools in understanding the various aspects related to Zn nutrition. Estimation of serum/plasma Zn was suggested for assessing the population Zn status while assessing the bioaccessible Zn following simulated gastrointestinal digestion of crop varieties such as rice helps in ranking the crops. Atomic absorption spectrometry (AAS) or inductively coupled plasma-mass spectrometry (ICP-MS) are widely used for Zn estimation. Zinquin, a Zn fluorophore, has been used for the localization of cellular Zn and labile Zn pools in biological fluids with extremely high sensitivity. However, it was not tested for its use in Zn estimation in serum/plasma or in assessing the Zn bioaccessibility from foods. In the current study, we demonstrate a sensitive method for Zn estimation in human plasma and validate it against the reference method (AAS) by comparing the paired measurements on the same samples. The method-related bias between zinquin with AAS was negligible (0.48 µg/dL), and the precision (CV) of the assay was < 5% across different Zn concentrations. In addition, we also demonstrated the utility of zinquin assay in estimating the bioaccessibility of Zn from rice varieties and showed that the method is again comparable to AAS. The zinquin method is capable of discriminating the differences in zinc bioaccessibility between polished and unpolished rice varieties. In the context of required low plasma volume (100 µL Vs 400 µL), excellent comparability of the results with the reference method and analytical simplicity could be particularly useful.

Imbalance of Plasma Copper and Zinc Levels and the Association Between the Cu/Zn Ratio and Lipid Peroxidation in Algerian Bipolar Patients

Trace elements, through their interaction with biomolecules, can play an important role in the pathophysiology of bipolar disorder and protect against oxidative stress effects. The purpose of this study is to examine plasma concentration levels of zinc (Zn) and copper (Cu) of Algerian patients, diagnosed with bipolar disorder, and to compare these levels with those of healthy controls. The Cu/Zn ratio was calculated to explore a possible correlation between these elements and lipid peroxidation in the study groups. A total of 33 patients diagnosed with bipolar disorder and 38 healthy subjects participated in this study. Plasma copper and zinc concentrations were measured using a polarographic analyzer. The marker of plasma lipid peroxidation (Malondialdehyde: MDA) was determined by UV spectrophotometry. Plasma Cu concentrations were higher in patients compared to controls (p < 0.05), while the Zn level was significantly lower. Consequently, the Cu/Zn ratio was significantly different between patients and controls. Regarding MDA, no significant difference was noticed between the two study groups. However, in patients, a negative correlation was found between MDA and Cu/Zn ratio (r= -0.38, p= 0.027). These results suggested that an elevated Cu/Zn ratio is associated with attenuated lipid peroxidation in our bipolar patients.

Trace elements repartition in body fluids, hair and organs in an autopsied population evaluated by ICP-MS high resolution

Exposure to metals and trace elements (TE) is universal and can cause toxicity in case of excessive exposure. We evaluated the concentrations and tissue distribution of 39 TE using high-resolution ICP-MS after total mineralization by microwave in twenty autopsied French subjects. We found a globally homogeneous distribution of TE in the body, with some accumulations in agents, involved in respiratory pathologies and classified as carcinogens, in the lungs. The liver, an organ of metabolism, appeared to concentrate Co, Fe, La, Mn, Mo, Pb and Zn. Fe seemed to accumulate in the spleen, the organ of hematopoiesis. The kidney showed high concentrations of some TE, which can cause nephrotoxicity. The use of microwave mineralization and high-resolution ICP-MS allowed accurate quantification and a very high sensitivity, without spectral interferences. The results obtained in this study could be used to support the interpretation of post-mortem metal concentrations in tissues.

Hair Toxic Trace Elements of Residents across the Caspian Oil and Gas Region of Kazakhstan: Cross-Sectional Study

This study aimed to assess the relationship between the content of toxic trace elements, such as aluminum (Al), arsenic (As), beryllium (Be), cadmium (Cd), mercury (Hg), and lead (Pb), in the hair of the adult population of western Kazakhstan and the distance of their residence from oil and gas fields. The cross-sectional study included 850 adults aged 18-60 years. Inductively coupled plasma mass spectrometry was used to measure the level of Al, As, Be, Cd, Hg, and Pb in hair. The relationship between the concentration of toxic trace elements in the hair and the distance from oil and gas fields was assessed in three groups (<16 km, 16-110 km, and >110 km), using multiple linear regression analysis. The highest concentration of Hg = 0.338 μg/g was determined in the group living near oil and gas fields (0-16 km), whereas the lowest concentration of Al = 3.127 μg/g and As = 0.028 μg/g was determined in participants living at a long distance (more than 110 km) (p < 0.001). The concentration of Al (-0.126 (CI: -0.174; -0.077)), Hg (-0.065 (CI: -0.129; -0.001)), and Pb (0.111 (CI: 0.045; 0.177)) is associated with the distance to oil and gas fields. The obtained data indicate a change in the toxic trace element content in the hair of residents in the Caspian region of western Kazakhstan, a change that is most pronounced in residents living in the zone of oil and gas pollution. The distance to the oil and gas fields affects the content of toxic elements in scalp hair. In particular, the concentration of Al and Hg is associated with a decrease in the distance to oil and gas fields, while the concentration of Pb is associated with an increase in the distance to these fields. The lowest content of Al and As was determined in the hair of study participants living in the most remote areas (more than 110 km from oil and gas fields). Our results demonstrate the need for the biomonitoring of toxic elements to determine long-term temporal trends in the impact of chemicals on public health in western Kazakhstan.

Newly found K+-Thioflavin T competitive binding to DNA G-quadruplexes and the development of a label-free fluorescent biosensor with extra low detection limit for K+ determination in urine samples

The determination of potassium ion K⁺ in body fluids is important in health monitoring and diagnoses. One of the interesting and simple methods for K⁺ detection is the use of label-free biosensors based on DNA G-quadruplexes (GQs) coupled with a specific fluorescent probe, such as Thioflavin T (ThT), which lights up when bound with K⁺-stabilized GQs. However, these biosensors are not generally sensitive. In this work, we found a solution: at a low concentration, K⁺ competes with ThT in binding to a bimolecular GQ or a tetramolecular GQ, resulting in a decrease in ThT fluorescence emission with increasing K⁺. Therefore, we developed a label-free turn-off fluorescent K⁺ sensor. The sensor provides a very low detection limit of 21.87 ± 0.59 nM. Other possible interfering components in urine did not exert any effect even at quantities that were 10-fold greater than their upper limit of normal concentrations found in urine samples. With its only requirement of diluting samples, the developed low-cost label-free probe and simple sensor was successfully applied to the direct detection of K⁺ in normal urine samples with high accuracy (recoveries ranged from 90% to 100%).

Essential Trace Elements in Scalp Hair of Residents across the Caspian Oil and Gas Region of Kazakhstan

Most of the country’s oil and gas fields are situated in West Kazakhstan, mainly on the Caspian Sea coast, causing significant damage to the local environment and contributing to an imbalance in the trace element composition of the human body. The study is aimed to evaluate the relationship between the concentration of essential trace elements in scalp hair of the western Kazakhstan adult population and the remoteness of their residence from oil and gas fields. The concentration of essential trace elements (Co, Cu, Fe, I, Mn, Se, Zn) in the hair of 850 individuals aged 18−60 years was determined by inductively coupled plasma mass spectrometry. In residents of settlements located at a distance of >110 km from oil and gas fields, the concentration of Cu and I in hair was significantly higher than in those closer to 110 km (p < 0.001). The content of Cu and I were associated with the distance to oil and gas fields (0.072 (95% CI: 0.050; 0.094)) and (0.121 (95% CI: 0.058; 0.185)), respectively. We detected a significant imbalance in the distribution of some essential trace elements in residents’ scalp hair from the Caspian region of western Kazakhstan, living near oil and gas fields. The concentrations of Cu and I were significantly interrelated with the distance to oil and gas fields. The level of copper in the hair of both inhabitants of the area most remote from oil and gas facilities and the entire population of western Kazakhstan as a whole remains significantly low. The data obtained provide evidence of the possible impact of pollutants generated by the oil and gas facilities on a shortage of essential trace elements and associated subsequent health risks.

Dietary Exposure to Essential and Non-essential Elements During Infants' First Year of Life in the New Hampshire Birth Cohort Study

Even the low levels of non-essential elements exposure common in the US may have health consequences especially early in life. However, little is known about the infant's dynamic exposure to essential and non-essential elements. This study aims to evaluate exposure to essential and non-essential elements during infants' first year of life and to explore the association between the exposure and rice consumption. Paired urine samples from infants enrolled in the New Hampshire Birth Cohort Study (NHBCS) were collected at approximately 6 weeks (exclusively breastfed) and at 1 year of age after weaning (n = 187). A further independent subgroup of NHBCS infants with details about rice consumption at 1 year of age also was included (n = 147). Urinary concentrations of 8 essential (Co, Cr, Cu, Fe, Mn, Mo, Ni, and Se) and 9 non-essential (Al, As, Cd, Hg, Pb, Sb, Sn, V, and U) elements were determined as a measure of exposure. Several essential (Co, Fe, Mo, Ni, and Se) and non-essential (Al, As, Cd, Hg, Pb, Sb, Sn, and V) elements had higher concentrations at 1 year than at 6 weeks of age. The highest increases were for urinary As and Mo with median concentrations of 0.20 and 1.02 µg/L at 6 weeks and 2.31 and 45.36 µg/L at 1 year of age, respectively. At 1 year of age, As and Mo urine concentrations were related to rice consumption. Further efforts are necessary to minimize exposure to non-essential elements while retaining essential elements to protect and promote children's health.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12403-022-00489-x.

Exposure of the residents around the Three Gorges Reservoir, China to chromium, lead and arsenic and their health risk via food consumption

Hydrological management of the Three Gorges Dam has resulted in the interception of heavy metals in the Three Gorges Reservoir (TGR). However, the exposure to heavy metals and health risks among local residents remained poorly understood. Here we collected 208 biomarker samples (hair) and 20 food species from typical regions in the TGR to assess the exposure levels of three toxic metals (Cr, Pb and As) in residents of the TGR, and subsequently investigated their health risk via dietary intake. Results indicated that hair Cr and As levels were below the reference value for normal people and threshold of skin lesions, respectively, whereas about 22% hair Pb exceeded the reference for clinical medicine, indicating a potential Pb exposure of local residents. Smoking habit and fish consumption were found to be predictors for hair Pb. In addition, the concentrations of heavy metals in all investigated food samples were below the limits of contaminants in food in China, except for Pb in the sweet potato and fish. The estimated daily intake of metals (DIMs) revealed that the intakes of Cr and As from studied food were under the recommended thresholds of Cr and As. However, the intake of Pb via diet exceeded the limit of the prevalence of chronic kidney disease and closed to the threshold for cardiovascular, which was probably associated with the high Pb concentrations of fish and sweet potato. Overall, residents around the TGR were at low exposure to Cr and As, but Pb exposure may need more attention.

The acute systemic toxicity of thallium in rats produces oxidative stress: attenuation by metallothionein and Prussian blue

Thallium (TI) is one of the most toxic heavy metals. Human exposure to Tl occurs through contaminated drinking water and from there to food, a threat to health. Recently, environmental contamination by Tl has been reported in several countries, urging the need for studies to determine the impact of endogenous and exogenous mechanisms preventing thallium toxicity. The cytoprotective effect of metallothionein (MT), a protein with high capacity to chelate metals, at two doses (100 and 600 µg/rat), was tested. Prussian blue (PB) (50 mg/kg) was administered alone or in combination with MT. A dose of Tl (16mg/kg) was injected i.p. to Wistar rats. Antidotes were administered twice daily, starting 24h after Tl injection, for 4 days. Tl concentrations diminished in most organs (p < 0.05) by effect of PB, alone or in combination with MT, whereas MT alone decreased Tl concentrations in testis, spleen, lung and liver. Likewise, brain thallium also diminished (p < 0.05) by effect of PB and MT alone or in combination in most of the regions analyzed (p < 0.05). The greatest diminution of Tl was achieved when the antidotes were combined. Plasma markers of renal damage increased after Tl administration, while PB and MT, either alone or in combination, prevented the raise of those markers. Only MT increased the levels of reduced glutathione (GSH) in the kidney. Finally, increased Nrf2 was observed in liver and kidney, after treatment with MT alone or in combination with PB. Results showed that MT alone or in combination with PB is cytoprotective after thallium exposure.

Aluminum Content of Human Milk and Antiperspirant Use

Background: Aluminum exposure may originate from numerous sources, including antiperspirants. Aluminum toxicity can cause a wide range of neurological impairments. Infants are exposed to aluminum through human milk (HM), formulas, total-parenteral-nutrition and vaccines. Due to potential risk of toxicity to both infants and women, it has been advised that lactating women decrease their use of aluminum-based products and antiperspirants. Our study aimed to determine whether the use of aluminum-based antiperspirants (ABA) affects aluminum levels in HM. Methods: This cross-sectional study included healthy mothers who exclusively breastfed infants (1 week to 5 months). Questionnaires were used to collect data on demographics, antiperspirant use and aluminum exposure. Mothers were instructed to express HM during the morning at first breastfeeding session. Aluminum levels were measured by atomic absorption spectrometry with a 5 ppb limit of detection. Results: Fifteen of the 58 (26%) recruited mothers used an aluminum-free antiperspirant (AFA) and 43 (74%) used an ABA. The range of aluminum concentration in HM was 0-100.8 μg/L (mean 11.4 ± 17.4 μg/L). The median aluminum level (Q1-Q3) was 6.5 μg/L (5.2-11.9) and 5.2 μg/L (3.46-9.4) in the AFA and ABA groups, respectively (p = 0.19). The aluminum levels were not affected by maternal age, education, diet, number of children, infant age, lactation stage or self-reported aluminum exposure. Conclusion: The data from this preliminary study demonstrate that the use of an ABA by lactating mothers does not increase their HM aluminum content. Additional studies with a larger cohort are warranted to confirm these findings.

Reference values for trace element levels in the human brain: A systematic review of the literature

Some trace elements (TE) are eminently toxic for humans (e.g., Al, Pb, Hg, Cd) and its presence in the central nervous system has been linked to the etiology of neurodegenerative diseases (ND). More recently, the focus has shifted to the potential role of the imbalances on essential TE levels (e.g., Fe, Cu, Zn, Se) within the brain tissue, and they have also been identified as potentially responsible for the cognitive decline associated with normal ageing and the development of some ND, although their definite role remains unclear. Accurately, well-defined reference values for TE levels in human body fluids and tissues are indispensable to identify possible disturbances in individual cases. Moreover, since the brain is a highly heterogeneous organ, with anatomically and physiologically very different areas, a detailed mapping of TE distribution across the brain tissue of normal individuals, with an in-depth analysis of TE levels in the different brain regions, is a mandatory prior work so that the results obtained from patients suffering from ND and other brain diseases can be interpreted. This review aims to compile and summarize the available data regarding TE levels in the different human brain regions of "normal" (non-diseased) individuals in order to contribute to the establishment of robust reference values. Fifty-four studies, published since 1960, were considered. The results showed a great variability between different studies. The potential sources of this variability are discussed. The need for increased harmonization of experimental strategies is highlighted in order to improve the comparability of the data obtained.

Disease Ionomics: Understanding the Role of Ions in Complex Disease

Ionomics is a novel multidisciplinary field that uses advanced techniques to investigate the composition and distribution of all minerals and trace elements in a living organism and their variations under diverse physiological and pathological conditions. It involves both high-throughput elemental profiling technologies and bioinformatic methods, providing opportunities to study the molecular mechanism underlying the metabolism, homeostasis, and cross-talk of these elements. While much effort has been made in exploring the ionomic traits relating to plant physiology and nutrition, the use of ionomics in the research of serious diseases is still in progress. In recent years, a number of ionomic studies have been carried out for a variety of complex diseases, which offer theoretical and practical insights into the etiology, early diagnosis, prognosis, and therapy of them. This review aims to give an overview of recent applications of ionomics in the study of complex diseases and discuss the latest advances and future trends in this area. Overall, disease ionomics may provide substantial information for systematic understanding of the properties of the elements and the dynamic network of elements involved in the onset and development of diseases.

ICP-MS trace element analysis in serum and whole blood

Trace elements and minerals are compounds that are essential for the support of a variety of biological functions and play an important role in the formation of and the defense against oxidative stress. Here we describe a technique, allowing sequential detection of the trace elements (K, Zn, Se, Cu, Mn, Fe, Mg) in serum and whole blood by an ICP-MS method using single work-up, which is a simple, quick and robust method for the sequential measurement and quantification of the trace elements Sodium (Na), Potassium (K), Calcium (Ca), Zinc (Zn), Selenium (Se), Copper (Cu), Iron (Fe), Manganese (Mn) and Magnesium (Mg) in whole blood as well as Copper (Cu), Selenium (Se), Zinc (Zn), Iron (Fe), Magnesium (Mg), Manganese (Mn), Chromium (Cr), Nickel (Ni), Gold (Au) and Lithium (Li) in human serum. For analysis, only 100 μl of serum or whole blood is sufficient, which make this method suitable for detecting trace element deficiency or excess in newborns and infants. All samples were processed and analyzed by ICP-MS (Agilent Technologies). The accuracy, precision, linearity and the limit of quantification (LOQ), Limit of Blank (LOB) and the limit of detection (LOD) of the method were assessed. Recovery rates were between 80–130% for most of the analyzed elements; repeatabilities (C_v %) calculated were below 15% for most of the measured elements. The validity of the proposed methodology was assessed by analyzing a certified human serum and whole blood material with known concentrations for all elements; the method described is ready for routine use in biomonitoring studies.

Simultaneous analysis of 25 trace elements in micro volume of human serum by inductively coupled plasma mass spectrometry (ICP-MS)

INTRODUCTION

In recent years, trace elements have gained importance as biomarkers in many chronic diseases. Unfortunately, the requirement for sample volume increases with the extent of investigation either for diagnosis or elucidating the mechanism of the disease. Here, we describe the method development and validation for simultaneous determination of 25 trace elements (lithium [Li], beryllium [Be], magnesium [Mg], aluminium [Al], vanadium [V], chromium [Cr], manganese [Mn], iron [Fe], cobalt [Co], nickel [Ni], copper [Cu], zinc [Zn], gallium [Ga], arsenic [As], selenium [Se], rubidium [Rb], strontium [Sr], silver [Ag], cadmium [Cd], caesium [Cs], barium [Ba], mercury [Hg], thallium [Tl], lead [Pb], uranium [U]) using only 20 μL of human serum.

METHODS

Serum samples were digested with nitric acid and hydrochloric acid (ratio 1:1, v/v) and analysed by inductively coupled plasma-mass spectrometry (ICP-MS). Seronorm®, a human-derived serum control material was used as quality control samples.

RESULTS

The coefficient of variations for both intra- and inter-day precisions were consistently <15% for all elements. The validated method was later tested on 30 human serum samples to evaluate its applicability.

CONCLUSION

We have successfully developed and validated a precise and accurate analytical method for determining 25 trace elements requiring very low volume of human serum.

Reference values for trace essential elements in the whole blood and serum samples of the adult Serbian population: significance of selenium deficiency

This study was aimed to determine reference values (RVs) for the manganese (Mn), copper (Cu), zinc (Zn), and selenium (Se) in the whole blood (B) and serum (S) samples of the Serbian population. Blood specimens were collected from healthy persons (n = 295; women/men ratio = 149/146; mean age: 42 ± 2 years). The RVs were calculated as lower limit (LL) and upper limit (UL) of the 95% confidence interval (CI) and were expressed as percentiles (P) in the range from P2.5 to P97.5. The influences of sex, age, and smoking habits on element profiles were considered. It was found that the contents of B-Cu and S-Cu were higher in women, while the contents of B-Zn and S-Zn were higher in men. Both trace elements were significantly increased in a group of persons above 40 when compared to a younger persons (≤ 40 years). According to smoking habits, increased content was found only for S-Mn in the nonsmoker's group (p < 0.05). Comparing our results to the results reported in other population groups worldwide, the Serbian population had significantly reduced content of Se in both types of samples. This finding could highlight the deficiency of Se in the investigated Serbian population and could contribute to the better understanding of the molecular basis for the increased incidence of thyroid and other diseases in which selenium plays a key role.

Pilot study of homeostatic alterations of mineral elements in serum of patients with age-related macular degeneration via elemental and isotopic analysis using ICP-mass spectrometry

Age-related macular degeneration (AMD), the main cause of irreversible blindness in people over 60 years of age, is an eye disease that evolves with loss of central vision. Although AMD manifests itself in the eye, blood is continuously flowing through the macular region, such that potential alterations in this region could be reflected in the composition of whole blood or plasma/serum. Therefore, the potential clinical relevance of analysis of serum samples was assessed because of the low degree of invasiveness of blood sampling. 40 initial samples (20 from controls and 20 from patients with the dry form of AMD) have been analysed in this work to investigate the possible occurrence of homeostatic alterations of essential mineral elements caused by the disease. Both major (Na, Mg, P and K) and trace (Fe, Cu and Zn) essential mineral elements were determined in blood serum using single-collector ICP-mass spectrometry. Also, the isotopic composition of Cu (an element proposed to be directly involved in the onset of AMD) was determined using multi-collector ICP-mass spectrometry. Unexpected light Cu isotopic compositions in three individuals assumed as controls, resulted in a re-evaluation of their clinical information and a later exclusion due to pathologies initially not accounted for. In this pilot study, a significant alteration in the δ⁶⁵Cu value has been found between the two final cohorts (AMD patients: n = 20; controls n = 17), with lower δ⁶⁵Cu values (i.e. an enrichment in the light ⁶³Cu isotope) in the case of AMD. Also, higher serum concentrations of the elements P and Zn were established in AMD at a systemic level.

A monolithic copolymer prepared from N-(4-vinyl)-benzyl iminodiacetic acid, divinylbenzene and N,N'-methylene bisacrylamide for preconcentration of cadmium(II) and cobalt(II) from biological samples prior to their determination by ICP-MS

A capillary monolith consisting of poly[N-(4-vinyl)-benzyl iminodiacetic acid-co-divinylbenzene-co-N,N'-methylene bisacrylamide), referred to as poly(VBIDA-DVB-Bis), has been prepared. It is shown to be an efficient sorbent for the enrichment of Co(II) and Cd(II). The two ions are completely retained by the monolith in the pH range from 4.0 to 9.0. The breakthrough curve tests were adopted to evaluate the adsorption performance of the monolith towards Co(II) and Cd(II). A dose-response model was used to describe the breakthrough curves of the two ions at different initial concentrations. The adsorption capacities for Co(II) and Cd(II) are 1.54 and 1.73 mg·m^-1 at a concentration level of 2.5 mg·L^-1, respectively. The enrichment factor is 100, and the required sample volume is 5 mL. Following elution of the two ions with 0.5 M HNO₃, they were quantified by ICP-MS. The limits of detection in a 1 mL sample are 0.35 ng·L^-1 for Co(II) and 0.44 ng·L^-1 for Cd(II). The method was applied to the determination of Co(II) and Cd(II) in spiked rice, human urine and seawater samples. Graphical abstract Schematic representation of a monolithic copolymer prepared from N-(4-vinyl)-benzyl iminodiacetic acid (VBIDA), divinylbenzene (DVB) and N,N'-methylene bisacrylamide (Bis) and its application for selective capturing of cadmium(II) and cobalt(II) from complex sample matrices prior to their determination by ICP-MS.

Aluminum in liver cells - the element species matters

Aluminum (Al) can be ingested from food and released from packaging and can reach key organs involved in human metabolism, including the liver via systemic distribution. Recent studies discuss the occurrence of chemically distinct Al-species and their interconversion by contact with biological fluids. These Al species can vary with regard to their intestinal uptake, systemic transport, and therefore could have species-specific effects on different organs and tissues. This work aims to assess the in vitro hepatotoxic hazard potential of three different relevant Al species: soluble AlCl₃ and two nanoparticulate Al species were applied, representing for the first time an investigation of metallic nanoparticles besides to mineral bound γ-Al₂O₃ on hepatic cell lines. To investigate the uptake and toxicological properties of the Al species, we used two different human hepatic cell lines: HepG2 and differentiated HepaRG cells. Cellular uptake was determined by different methods including light microscopy, transmission electron microscopy, side-scatter analysis, and elemental analysis. Oxidative stress, mitochondrial dysfunction, cell death mechanisms, and DNA damage were monitored as cellular parameters. While cellular uptake into hepatic cell lines occurred predominantly in the particle form, only ionic AlCl₃ caused cellular effects. Since it is known, that Al species can convert one into another, and mechanisms including 'trojan-horse'-like uptake can lead to an Al accumulation in the cells. This could result in the slow release of Al ions, for which reason further hazard cannot be excluded. Therefore, individual investigation of the different Al species is necessary to assess the toxicological potential of Al particles.

Strontium isotope ratios of human hair from the United States: Patterns and aberrations

RATIONALE

Strontium isotope ratios (⁸⁷ Sr/⁸⁶ Sr) of hair may be a valuable tool to estimate human provenance. However, the systematics and mechanisms controlling spatial variation in ⁸⁷ Sr/⁸⁶ Sr of modern human hair remain unclear. Here, we measure ⁸⁷ Sr/⁸⁶ Sr of hair specimens from across the USA to assess the presence of geospatial relationships.

METHODS

Ninety-eight human hair specimens were collected from salon/barbershop floors in 48 municipalities throughout the conterminous USA. [Sr] and ⁸⁷ Sr/⁸⁶ Sr ratios were measured from hair using quadrupole and multi-collector inductively coupled plasma mass spectrometers, respectively. The [Sr] and ⁸⁷ Sr/⁸⁶ Sr ratios of hair were compared with the measured [Sr] and ⁸⁷ Sr/⁸⁶ Sr ratios of tap waters from the collection locations. In addition, the ⁸⁷ Sr/⁸⁶ Sr ratio of hair was compared with the modeled ratios of bedrock and surface waters.

RESULTS

Hair color was independent of the ⁸⁷ Sr/⁸⁶ Sr ratio, but related to [Sr]. The ⁸⁷ Sr/⁸⁶ Sr ratios of hair and leachate were not statistically different and were positively correlated; however, in several hair-leachate pairs, the ratios were conspicuously different. The ⁸⁷ Sr/⁸⁶ Sr ratios of both hair and leachate were linearly correlated with tap water. The ⁸⁷ Sr/⁸⁶ Sr ratio of hair was also significantly correlated with the modeled ratio of bedrock and surface waters, although the ⁸⁷ Sr/⁸⁶ Sr ratio of hair was most strongly correlated with the measured ratio of tap water.

CONCLUSIONS

The ⁸⁷ Sr/⁸⁶ Sr ratio of hair is related to the ratio of tap water, which varied geographically. The ratio of hair provided geographic information about an individual's recent residence. Differences in the ⁸⁷ Sr/⁸⁶ Sr ratios of hair and hair leachate may be concomitant with travel and could potentially be used as a screening tool to identify recent movements.

A porous organic polymer with magnetic nanoparticles on a chip array for preconcentration of platinum(IV), gold(III) and bismuth(III) prior to their on-line quantitation by ICP-MS

A chip-based array is described for magnetic solid-phase microextraction (MSPME) of the ions of Pt, Au and Bi. Magnetic porous organic polymers (MOPs) prepared from magnetite nanoparticles and 1,3,5-tris(4-aminophenyl)benzene are introduced as a novel adsorbent. Eight solid phase extraction columns packed with MOPs were integrated in parallel on a microfluidic chip for array microextraction. After elution with a 12% (m/v) solution of cysteamine hydrochloride (pH 8.0), the eluent is introduced into an ICP-MS instrument for quantification. Under the optimized conditions, the limits of detection for Pt, Au and Bi are 8.6, 4.4 and 3.4 ng L^-1, respectively. The sample throughput is 7 h^-1, and the adsorption capacities are 32, 24 and 24 μg mg^-1 for Pt, Au and Bi, respectively. The method was validated by the determination of Bi in a certified reference material (GSH-1A; human hair), and the values obtained coincided with the certified value. This method was also applied to the determination of Pt, Au and Bi in (spiked) urine and cell samples, and good recoveries (85.8-113%) were achieved. The method is highly sensitive and has a high throughput and a low sample/reagent consumption (with 500 HeLa cells consumed). Graphical abstract Schematic presentation of the magnetic packed column, microfluidic chip, and online chip-based MSPME-ICPMS system. Design sketch of the online system: microextraction unit (blue lines), microvalves (black lines), outlet channels (yellow lines), permanent magnets (red), urine and cell samples.

Biomonitoring of metals and trace elements in urine of central Ethiopian populations

Biomonitoring of chemical concentrations in humans is important for detecting, monitoring, and addressing a wide range of health threats. However, it is virtually absent across many African nations, including Ethiopia. This study aims to determine urinary concentrations for metals and trace elements in populations living in the central Ethiopian Rift Valley. The region is unindustralized, rural, and characterized by unique geologic rifting and volcanic activities that have produced vast pyroclastic materials, forming its aquifer and fertile agricultural soils. Millions of people in the region rely on wells for drinking water and are engaged in cereal-based subsistence agriculture. We enrolled a total of 386 residents aged 10-50 years old (201 females and 185 males). The levels of 23 elements except F^─ were quantified in water and urine samples by ICP-MS. Mean concentrations of B, F^─, Ca, and Mg were measured in mg/L levels, while concentrations of Mo, Zn, Sr, Rb, and Li ranged between 100 and 700 μg/L. Mean concentrations between 5 and 15 μg/L were found for Ni, Cu, and Mn, while Ag, Be, Cd, Co, Pb, Sb, Th, TI, and U were all below 5 μg/L. Arsenic and Al had mean concentrations between 30 and 50 μg/L. Mean urinary concentrations of Ca, Cu, Mg, Pb, Sr, and Zn were significantly higher in males than females, whereas Co and Mn were higher in females. Finally, younger individuals (10-30 years) had significantly higher mean concentrations of B, Cd, Co, Mg, Mo, and Pb than those between 31 and 50 years, whereas only Ca was higher in the older age group. The concentration ranges of B, Mo, Mn, TI, Li, Zn, and in particular F^─ (0.44-44.6 mg/L) and As (2.2-164 μg/L) in urine were higher than the reference ranges reported in healthy unexposed North American and European populations, while those for the remaining 16 elements were comparable to published reference ranges from such settings. The established concentration ranges are important to monitor future changes in exposure, and risk factors for disease, that might stem from the economic growth and industrialization that is currently underway in the region.

Microfluidic array surface ion-imprinted monolithic capillary microextraction chip on-line hyphenated with ICP-MS for the high throughput analysis of gadolinium in human body fluids

A novel method by hyphenating chip-based array ion-imprinted monolithic capillary microextraction with ICP-MS was proposed for the online analysis of trace Gd in biological samples.

Determination of toxic and essential trace elements in serum of healthy and hypothyroid respondents by ICP-MS: A chemometric approach for discrimination of hypothyroidism

Inductively coupled plasma-mass spectrometry ((ICP-MS)) was used to determine three toxic (Ni, As, Cd) and six essential trace elements (Cr, Mn, Co, Cu, Zn, Se) in blood serum of patients with hypothyroidism (Hy group) and healthy people (control group), in order to set the experimental conditions for accurate determination of a unique profile of these elements in hypothyroidism. Method validation was performed with standard reference material of the serum by varying the sample treatment with both standard and collision mode for analysis of elements isotopes. Quadratic curvilinear functions with good performances of models and the lowest detection limits were obtained for ⁵²Cr, ⁶⁶Zn, ⁷⁵As, ¹¹²Cd in collision mode, and ⁵⁵Mn, ⁵⁹Co, ⁶⁰Ni, ⁶⁵Cu, ⁷⁸Se in standard mode. Treatment of serum samples with aqueous solution containing nitric acid, Triton X-100 and n-butanol gave the best results. Chemometric tools were applied for discrimination of patients with hypothyroidism. All nine elements discriminated Hy group of samples with almost the same discriminating power as indicated by their higher values for this group of patients. Statistically significant correlation (p < 0.01) was observed for several elements. Results indicated clear differences in element profile between Hy and control group and it could be used as a unique profile of hypothyroid state.

Alterations of serum macro-minerals and trace elements are associated with major depressive disorder: a case-control study

BACKGROUND

Major depressive disorder (MDD) is a mixed disorder with the highly irregular course, inconsistent response to treatment and has no well-known mechanism for the pathophysiology. Major causes of depression are genetic, neurobiological, and environmental. However, over the past few years, altered serum levels of macro-minerals (MM) and trace elements (TE) have been recognized as major causative factors to the pathogenesis of many mental disorders. The purpose of this study was to determine the serum levels of MM (calcium and magnesium) and TE (copper, iron, manganese, selenium, and zinc) in MDD patients and find out their associations with depression risk.

METHODS

This prospective case-control study recruited 247 patients and 248 healthy volunteers matched by age and sex. The serum levels of MM and TE were analyzed by atomic absorption spectroscopy (AAS). Statistical analysis was performed with independent sample t-tests and Pearson's correlation test.

RESULTS

We found significantly decreased concentrations of calcium and magnesium, iron, manganese, selenium, and zinc in MDD patients compared with control subjects (p < 0.05). But the concentration of copper was significantly increased in the patients than control subjects (p < 0.05). Data obtained from different inter-element relations in MDD patients and control subjects strongly suggest that there is a disturbance in the element homeostasis.

CONCLUSION

Our study suggests that altered serum concentrations of MM and TE are major contributing factors for the pathogenesis of MDD. Alterations of these elements in serum levels of MDD patients arise independently and they may provide a prognostic tool for the assessment of depression risk.

Assessing the boron nutritional status by analyzing its cummulative frequency distribution in the hair and whole blood

Boron is a non-essential ubiquitous trace element in the human body. The aim of this study was to assess boron nutritional status by analyzing boron frequency distribution in the long-term biological indicator tissue of hair and the short-term biological indicator of whole blood. Hair samples were analyzed in 727 apparently healthy subjects (263 ♂ and 464 ♀) and the whole blood boron was analyzed in the random subsample of them (80 ♂ and 152 ♀). Samples were analyzed by the ICP-MS at the Center for Biotic Medicine, Moscow, Russia. The adequate reference range for hair boron concentration was (μg∙g^-1) 0.771- 6.510 for men and distinctly lower 0.472-3.89 for women; there was no detectable difference in the whole blood boron for the adequate reference range between men (0.020-.078) and women (0019-0.062). Boron may play an essential role in the metabolism of the connective tissue of the biological bone matrix.

3D-Printed Microflow Injection Analysis Platform for Online Magnetic Nanoparticle Sorptive Extraction of Antimicrobials in Biological Specimens as a Front End to Liquid Chromatographic Assays

In this work, the concept of 3D-printed microflow injection (3D-μFI) embodying a dedicated multifunctional 3D-printed stator onto a rotary microvalve along with a mesofluidic sample preparation platform is proposed for the first time. A transparent 3D-printed stereolithographic mesofluidic chip device accommodating polyaniline (PANI) decorated magnetic nanoparticles (32.5 ± 3.8 mg) is harnessed to in-line sorptive microextraction as a front end to liquid chromatography with peak focusing. As a proof-of-concept application, the 3D-μFI assembly was resorted to matrix cleanup and automatic programmable-flow determination of organic emerging contaminants (4-hydroxybenzoate analogues and triclosan as antimicrobial model analytes) in human saliva and urine samples. By using a sample volume of 1.0 mL with a loading flow rate of 200 μL min^-1, an eluent volume of 120 μL at 80 μL min^-1, and online HPLC injection of 300 μL of the mixture of eluate and Milli-Q water (in a 1:2 ratio) to prevent band broadening effects of the most polar analytes, the limits of detection (3σ criterion) ranged from 1.1 to 4.5 ng mL^-1 for methylparaben (MP), ethylparaben (EP), propylparaben (PrP), phenylparaben (PhP), butylparaben (BP), and triclosan (TCS). Enhancement factors of 16-25 were obtained for the target analytes. Spike recoveries ranged from 84 to 117% for both saliva and urine samples. The online 3D-μFI hyphenated method is synchronized with the chromatographic separation and features a chip lifetime of more than 20 injections with minimal losses of moderately nonpolar compounds on the walls of the mesofluidic device.

Assessment of Typical Heavy Metals in Human Hair of Different Age Groups and Foodstuffs in Beijing, China

Human hair of different age groups and foodstuff samples were collected in Beijing, China. The concerned metals—Cd, Cr, Pb, As, and Hg—were analyzed, and the metal levels in relation to age, gender, and dietary intake were further assessed. Results showed the highest level of the metals was shown by Pb, with an average concentration of 1.557 ± 0.779 mg/kg, followed by Cr (0.782 ± 0.394), Hg (0.284 ± 0.094), As (0.127 ± 0.078), and Cd (0.071 ± 0.032), following a decreasing order of Pb > Cr > Hg > As > Cd, which were all below the upper limit of normal values in China. The heavy metal concentrations varied greatly among different age groups, and higher concentrations for Cd, Cr, Pb, and As appeared in female hair, whereas higher Hg concentration were found in male hair, suggesting that age and gender were not crucial factors for assessing metal concentrations in human hair. The ingestion of cereals and vegetables were the main route by which heavy metals in the environment create hazardous health effects for local inhabitants, but the estimated metal intakes through food consumption were all lower than the proposed limit of Provisional Tolerable Weekly Intake (PTWI), indicating that heavy metals posed no health risks for the inhabitants. Furthermore, little relationship was found between metal intakes and the corresponding metal levels in hair. Nevertheless, the results of this study can be used to analyze the internal heavy metal burden in the resident population of Beijing area and can also serve as reference for further studies.

Hair for a long-term biological indicator tissue for assessing the strontium nutritional status of men and women

Strontium (Sr) is a trace element that closely resembles calcium metabolism. At the present time there is no available long-term biological indicator tissue for assessing the human Sr nutritional status. Here we have presented a novel concept on how to assess the Sr nutritional status by studying the frequency distribution properties of hair Sr (^SrH) concentration. In this prospective, observational, cross-sectional, and exploratory epidemiological study, we analyzed ^SrH in 311 apparently healthy adult Croatians (123 men, 188 women). Hair strontium was analyzed by the ICP-MS. The natural frequency distribution of ^SrH followed the Power law, so that the data were analyzed by fitting the logistic bioassay sigmoid curve (ogive) of median derivatives. Women tend to accumulate three and a half time more ^SrH than men (median men 867ngg^-1 vs. median women 3120ngg^-1). The normal (adequate) linear physiological response range of the sigmoid curve was 351-3489ngg^-1 for men and 846-8457ngg^-1 for women. Values below that linear range are considered to indicate deficient Sr nutritional status, whereas values above that linear range indicate excessive strontium exposure. Hair, as a long-term, and whole blood as a short-term biological indicator tissues were not commensurable entities. Similarly, ^SrH accumulation was not age dependent in either men or women. Hair strontium is a reliable long-term biological indicator tissue for assessing the strontium nutritional status.

ICP-MS/MS-Based Ionomics: A Validated Methodology to Investigate the Biological Variability of the Human Ionome

We here describe the development, validation and application of a quantitative methodology for the simultaneous determination of 29 elements in human serum using state-of-the-art inductively coupled plasma triple quadrupole mass spectrometry (ICP-MS/MS). This new methodology offers high-throughput elemental profiling using simple dilution of minimal quantity of serum samples. We report the outcomes of the validation procedure including limits of detection/quantification, linearity of calibration curves, precision, recovery and measurement uncertainty. ICP-MS/MS-based ionomics was used to analyze human serum of 120 older adults. Following a metabolomic data mining approach, the generated ionome profiles were subjected to principal component analysis revealing gender and age-specific differences. The ionome of female individuals was marked by higher levels of calcium, phosphorus, copper and copper to zinc ratio, while iron concentration was lower with respect to male subjects. Age was associated with lower concentrations of zinc. These findings were complemented with additional readouts to interpret micronutrient status including ceruloplasmin, ferritin and inorganic phosphate. Our data supports a gender-specific compartmentalization of the ionome that may reflect different bone remodelling in female individuals. Our ICP-MS/MS methodology enriches the panel of validated "Omics" approaches to study molecular relationships between the exposome and the ionome in relation with nutrition and health.

New extracellular thermostable oxalate oxidase produced from endophytic Ochrobactrum intermedium CL6: Purification and biochemical characterization

Oxalate oxidase (EC 1.2.3.4) catalyzes the oxidative cleavage of oxalate to carbon dioxide with the reduction of molecular oxygen to hydrogen peroxide. Oxalate oxidase found its application in clinical assay for oxalate in blood and urine. This study describes the purification and biochemical characterization of an oxalate oxidase produced from an endophytic bacterium, Ochrobactrum intermedium CL6. The cell-free fermentation broth was subjected to two-step enzyme purification, which resulted in a 58.74-fold purification with 83% recovery. Specific activity of the final purified enzyme was 26.78 U mg(-1) protein. The enzyme displayed an optimum pH and temperature of 3.8 and 80°C, respectively, and high stability at 4-80°C for 6 h. The enzymatic activity was not influenced by metal ions and chemical agents (K(+), Na(+), Zn(2+), Fe(3+), Mn(2+), Mg(2+), glucose, urea, lactate) commonly found in serum and urine, with Cu(2+) being the exception. The enzyme appears to be a metalloprotein stimulated by Ca(2+) and Fe(2+). Its Km and Kcat for oxalate were found to be 0.45 mM and 85 s(-1), respectively. This enzyme is the only known oxalate oxidase which did not show substrate inhibition up to a substrate concentration of 50 mM. Thermostability, kinetic properties, and the absence of substrate inhibition make this enzyme an ideal candidate for clinical applications.

Determinants of serum manganese levels in an Italian population

Manganese (Mn) is both essential and toxic for humans, mainly depending on the total levels and its species. Main sources of exposure include food and air pollution, particularly motorized traffic. We sought to determine the potential influence of these sources on serum total levels of Mn and Mn species. We selected a random sample of municipality residents from an Italian urban municipality, from whom we collected detailed personal information, dietary habits and a blood sample for serum Mn determination. We also assessed outdoor air Mn exposure, by modeling levels of particulate matter ≤10 µm (PM10) from motorized traffic at the residence of geocoded subjects. Serum Mn species generally showed higher levels in males and positive correlation with age, while no such differences were found according to smoking habits or use of dietary supplements. Among nutrients, only iron intake showed a relation with Mn [an inverse correlation with Mn‑ferritin (Mn‑Fer) and a direct one with inorganic‑Mn (Inorg‑Mn)]. Meat consumption directly correlated and fish and seafood inversely correlated with total Mn, Mn‑transferrin (Mn‑Tf) and Mn-citrate (Mn-Cit). Fruits and vegetables, including legumes and nuts, generally showed a positive correlation with all Mn species, especially Mn‑Cit, and an inverse one with Inorg‑Mn. Odds ratios (ORs) of having serum Mn levels above median value increased with increasing PM10 tertiles, with an OR for highest‑to‑lowest tertile of 7.40 (1.36‑40.25) in multivariate analysis. Analyses for Mn species did not highlight a clear comparable pattern. In conclusion, our results seem to demonstrate that PM10 exposure positively influences total Mn serum levels, while single Mn species show conflicting results.

Levels of five metals in male hair from urban and rural areas of Chongqing, China

Heavy metals were measured by flame atomic absorption in male hair from residents in urban and rural areas in Chongqing. The median values of the Cd, Cu, Ni, Pb and Zn were 2.90, 23.9, 9.31, 39.3 and 203 μg/g in urban areas and 0.84, 13.4, 5.56, 14.5 and 169 μg/g in rural area, respectively. The levels of Cd, Ni and Pb both in urban and rural areas lie at the high end of the worldwide figures. The differences in heavy metal distribution pattern indicated that there were more sources of Cd and Pb in urban areas. The levels of Cd were increasing along with the growth of age except for the aged people in urban areas, and no significant relationship was observed between the levels of the heavy metal and the age. It is noticed that the hair of smokers exhibited more heavy metal levels than that of non-smokers both in urban and rural areas. In addition, the hair metal levels of the smokers and non-smokers in urban areas were significantly higher than those in rural area, respectively. Significant pairwise correlations (p < 0.01) were observed among Cd, Cu, Ni and Pb in rural area and only between Cu and Ni and between Pb and Ni in urban areas, indicating the elements in these two areas might originate from different sources. The elevated levels of Cd, Pb and Ni implied that the residents both in urban and rural areas might be at high risk of toxic metal exposure, especially for the children.

Relationship between e-waste recycling and human health risk in India: a critical review

Informal recycling of waste (including e-waste) is an emerging source of environmental pollution in India. Polychlorinated biphenyls (PCBs), polychlorinated diphenyl ethers (PBDEs), and heavy metals, among other substances, are a major health concern for workers engaged in waste disposal and processing, and for residents living near these facilities, and are also a detriment to the natural environment. The main objective of this review article was to evaluate the status of these impacts. The review found that, huge quantity of e-waste/waste generated, only a small amount is treated formally; the remainder is processed through the informal sector. We also evaluated the exposure pathways, both direct and indirect, and the human body load markers (e.g., serum, blood, breast milk, urine, and hair), and assessed the evidence for the association between these markers and e-waste exposure. Our results indicated that the open dumping and informal e-waste recycling systems should be replaced by the best available technology and environmental practices, with proper monitoring and regular awareness programs for workers and residents. Further and more detailed investigation in this area is also recommended.

High hair selenium mother to fetus transfer after the Brazil nuts consumption

Lactating mother and her two month old healthy daughter (APGAR 10) gave their scalp hair for a multielement profile analysis; 25 elements were analyzed with the ICP MS. Mother's hair was divided into 5cm long segment proximal to the scull (Young), and the distal segment further up to the hair tip (Old). One centimeter of hair records one month of the metabolic activity of the bioelements in the body. Mother's Young hair and daughters hair have 2.70 and 9.74μgg(-1)Se, a distinctly higher Se concentrations than the Old hair of 0.87μgg(-1). The adequate hair Se concentrations in Croatia women population vary from 0.08 to 0.63μgg(-1); values below or above that range indicate deficiency or excess, respectively. Dietary recall revealed that during the last trimester of pregnancy and over a period of a week, the mother has consumed 135g of Brazil nuts (Bertholletia excelsa) (BN); BN is an exceptionally rich Se dietary source. The amount of Se in BN varies and one week consumption of 135g of BN may result in Se daily intake of 367 to 492μgg(-1)day(-1) over a period of seven consecutive days, and what is about or exceeds the Upper Limit of daily selenium intake of 400μg(-1)g(-1). The excessively high infant hair Se mirrored a natural high mother to fetus transplacental transfer of bio elements in the last trimester of pregnancy. The potential toxicological risks of such a high Se transfer remains to be elucidated.

Novel Zn2+ Modulated GPR39 Receptor Agonists Do Not Drive Acute Insulin Secretion in Rodents

Type 2 diabetes (T2D) occurs when there is insufficient insulin release to control blood glucose, due to insulin resistance and impaired β-cell function. The GPR39 receptor is expressed in metabolic tissues including pancreatic β-cells and has been proposed as a T2D target. Specifically, GPR39 agonists might improve β-cell function leading to more adequate and sustained insulin release and glucose control. The present study aimed to test the hypothesis that GPR39 agonism would improve glucose stimulated insulin secretion in vivo. A high throughput screen, followed by a medicinal chemistry program, identified three novel potent Zn²⁺ modulated GPR39 agonists. These agonists were evaluated in acute rodent glucose tolerance tests. The results showed a lack of glucose lowering and insulinotropic effects not only in lean mice, but also in diet-induced obese (DIO) mice and Zucker fatty rats. It is concluded that Zn²⁺ modulated GPR39 agonists do not acutely stimulate insulin release in rodents.

TiO₂ nanoparticles functionalized monolithic capillary microextraction online coupled with inductively coupled plasma mass spectrometry for the analysis of Gd ion and Gd-based contrast agents in human urine

In this work, a novel method of TiO2 nanoparticles (NPs) functionalized monolithic capillary microextraction (CME) online coupling with inductively coupled plasma mass spectrometry (ICPMS) was developed for the sequential determination of Gd(3+) and Gd-based contrast agents in human urine samples. The monolithic capillary was prepared by embedding anatase TiO2 NPS in the poly(methacrylic acid-ethylene glycol dimethacrylate) (MAA-EDMA) framework. The Gd(3+) and Gd-based contrast agents (such as gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) and Gd-DTPA-bismethylamide (Gd-DTPA-BMA)) display different adsorption behaviors on the prepared monolithic capillary which possesses the adsorption properties of both anatase TiO2 NPS and poly(MAA-EDMA) monolith. Under the optimized conditions, the limits of detection (LODs) were found to be 3.6, 3.2, and 4.5 ng L(-1) for Gd(3+), Gd-DTPA, and Gd-DTPA-BMA, respectively, which are the lowest up to date. The enrichment factor was 25-fold with the sample throughput of 5 h(-1). The proposed method was validated by the analysis of Gd(3+) and Gd-DTPA in the healthy human urine samples as well as Gd(3+) and Gd-DTPA-BMA in patient urine samples. It was found that only a small amount of the free Gd(3+) was released from Gd-DTPA-BMA, and accurate results could be obtained since no oxidation/reduction or subtraction is involved in this method. This method is simple, sensitive, and rapid and provides a very attractive nonchromatography strategy for the speciation of Gd(3+) and Gd-based contrast agents in urine samples.

Nephrotoxic contaminants in drinking water and urine, and chronic kidney disease in rural Sri Lanka

Chronic kidney disease of unknown ("u") cause (CKDu) is a growing public health concern in Sri Lanka. Prior research has hypothesized a link with drinking water quality, but rigorous studies are lacking. This study assesses the relationship between nephrotoxic elements (namely arsenic (As), cadmium (Cd), lead (Pb), and uranium (U)) in drinking water, and urine samples collected from individuals with and/or without CKDu in endemic areas, and from individuals without CKDu in nonendemic areas. All water samples - from a variety of source types (i.e. shallow and deep wells, springs, piped and surface water) - contained extremely low concentrations of nephrotoxic elements, and all were well below drinking water guideline values. Concentrations in individual urine samples were higher than, and uncorrelated with, those measured in drinking water, suggesting potential exposure from other sources. Mean urinary concentrations of these elements for individuals with clinically diagnosed CKDu were consistently lower than individuals without CKDu both in endemic and nonendemic areas. This likely stems from the inability of the kidney to excrete these toxic elements via urine in CKDu patients. Urinary concentrations of individuals were also found to be within the range of reference values measured in urine of healthy unexposed individuals from international biomonitoring studies, though these reference levels may not be safe for the Sri Lankan population. The results suggest that CKDu cannot be clearly linked with the presence of these contaminants in drinking water. There remains a need to investigate potential interactions of low doses of these elements (particularly Cd and As) with other risk factors that appear linked to CKDu, prior to developing public health strategies to address this illness.

Assessing metal exposures in a community near a cement plant in the Northeast U.S

Cement production is a major source of metals and metalloids in the environment, while exposures to metals and metalloids may impact human health in the surrounding communities. We recruited 185 participants living in the vicinity of a cement plant in the northeast U.S., and measured the levels of aluminum (Al), arsenic (As), cadmium (Cd), lead (Pb), mercury (Hg), and selenium (Se) in blood and Hg in hair samples from them. A questionnaire was used to assess potential sources of Hg exposure. Multivariate regressions and spatial analyses were performed to evaluate the relative importance of different routes of exposures. The metal concentrations in blood or hair samples of our study participants were comparable to the U.S. general or regional population. Smoking contributed significantly to Cd and Pb exposures, and seafood consumption contributed significantly to Hg and As exposures, while variables related to the cement plant were not significantly associated with metal concentrations. Our results suggest that our study population was not at elevated health risk due to metal exposures, and that the contribution of the cement plant to metal exposures in the surrounding community was minimal.

Restricted accessed nanoparticles for direct magnetic solid phase extraction of trace metal ions from human fluids followed by inductively coupled plasma mass spectrometry detection

Restricted accessed magnetic nanoparticles were synthesized and applied for direct extraction of trace metals from human fluids.

Identifying alkali metal inhibitors of crystal growth: a selection criterion based on ion pair hydration energy

We show that alkali metals function as effective modifiers of calcium oxalate monohydrate (COM) crystallization wherein alkali-oxalate ion parings reduce the rate of crystal growth by as much as 60%.