Simple and sensitive determination of Cr (III), Cu (II) and Pb (II) in tea infusions using AgNPs-modified resin combined with laser-induced breakdown spectroscopy.

The detection of heavy metals in tea infusions is important because of the potential health risks associated with their consumption. Existing highly sensitive detection methods pose challenges because they are complicated and time-consuming. In this study, we developed an innovative and simple method using Ag nanoparticles-modified resin (AgNPs-MR) for pre-enrichment prior to laser-induced breakdown spectroscopy for the simultaneous analysis of Cr (III), Cu (II), and Pb (II) in tea infusions. Signal enhancement using AgNPs-MR resulted in amplification with limits of detection of 0.22 µg L-1 for Cr (III), 0.33 µg L-1 for Cu (II), and 1.25 µg L-1 for Pb (II). Quantitative analyses of these ions in infusions of black tea from various brands yielded recoveries ranging from 83.3% to 114.5%. This method is effective as a direct and highly sensitive technique for precisely quantifying trace concentrations of heavy metals in tea infusions.

Synergistic optical sensing: Selective colorimetric analysis of copper in environmental and biological samples.

A groundbreaking optical sensing membrane has been engineered for the accurate assessment of copper ions. The pliable poly(vinyl chloride) membrane is formulated through the integration of sodium tetraphenylborate (Na-TPB), 4-(2-hydroxy-4-nitro azobenzene)-2-methyl-quinoline (HNAMQ), and tri-n-octyl phosphine oxide (TOPO), in conjunction with o-nitrophenyl octyl ether (o-NPOE). The sensor membrane undergoes a thorough investigation of its composition to optimize performance, revealing that HNAMQ serves a dual role as both an ionophore and a chromoionophore. Simultaneously, TOPO contributes to enhancing the complexation of HNAMQ with copper ions. Demonstrating a linear range for Cu2+ ions spanning from 5.0 × 10-9 to 7.5 × 10-6 M, the proposed sensor membrane showcases detection and quantification limits of 1.5 × 10-9 and 5.0 × 10-9 M, respectively. Rigorous assessments of potential interferences from other cations and anions revealed no observable disruptions in the detection of Cu2+. With no discernible HNAMQ leaching, the membrane demonstrates rapid response times and excellent durability. The sensor exhibits remarkable selectivity for Cu2+ ions and can be regenerated through exposure to 0.05 M EDTA. Successful application of the sensor in determining the presence of Cu2+ in biological (blood, liver and meat), soil, food (coffee, black tea, sour cherry juice, black currant, and milk powder) and environmental water samples underscores its efficacy.

Evaluation of urinary trace element levels in patients with opioid use disorder undergoing methadone treatment in western Iran.

The monitoring of essential and toxic elements in patients with Opioid Use Disorder (OUD) undergoing methadone treatment (MT) is important, and there is limited previous research on the urinary levels of these elements in MT patients. Therefore, the present study aimed to analyze certain elements in the context of methadone treatment compared to a healthy group. In this study, patients with opioid use disorder undergoing MT (n = 67) were compared with a healthy group of companions (n = 62) in terms of urinary concentrations of some essential elements (selenium (Se), zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), calcium (Ca)) and toxic elements (lead (Pb), cadmium (Cd), arsenic (As), and chromium (Cr)). Urine samples were prepared using the acid digestion method with a mixture of nitric acid and perchloric acid and assessed using the ICP-MS method. Our results showed that the two groups had no significant differences in terms of gender, education level, occupation, and smoking status. Urinary concentrations of Se, Cu, and Fe levels were significantly lower in the MT group compared to the healthy subjects. However, the concentrations of Pb, Cd, As, Mn, Cr, and Ca in the MT group were higher than in the healthy group (p < 0.05). No significant difference was established between the levels of Zn in the two groups (p = 0.232). The results of regression analysis revealed that the differences between the concentration levels of all metals (except Zn) between two groups were still remained significant after adjusting for all variables (p < 0.05). The data obtained in the current study showed lower urinary concentrations of some essential elements and higher levels of some toxic elements in the MT group compared to the healthy subjects. These findings should be incorporated into harm-reduction interventions.

Metal bioaccumulation and histological alterations in Oreochromis andersonii at Itezhi-tezhi Dam downstream of a mining area in the Central Province of Zambia.

The Itezhi-tezhi Dam on the Kafue River in Zambia is a major capture fishery. However, the upstream reaches of the Kafue River receive effluents from copper mines. It was unclear whether fish health in the dam is adversely affected due to the mining effluents. We investigated the health status of fish in Itezhi-tezh Dam using a histology-based fish health assessment protocol with Oreochromis andersonii as a bioindicator. Fish were sampled in the Itezhi-tezh Dam and at a reference site further upstream on the Kafue River before it enters the mining region. Metal bioaccumulation, biometric indices and histological alterations in the gills, gonads, hearts, kidneys and livers were assessed. The findings revealed significantly higher copper and selenium sediment concentrations (p = 0.02843 and p = 0.02107 respectively), bioaccumulation of copper and selenium, and increased histological alterations in the gills, kidneys and livers of fish in the Itezhi-tezhi Dam.

Benchtop x-ray fluorescence to quantify elemental content in nails non-destructively.

Metals continue to impose health issues among world populations. A non-invasive alternative biomarker for assessment of metals and other elements has been explored in other studies using toenail samples. Some benefits of using toenails as biomarkers over blood samples include cost efficiency, ease of collection, and a longer biological half-life within samples. The objective of this study was to employ desktop XRF for the purpose of measuring metal concentrations in human nail samples, thus conducting a non-destructive assessment. These benefits paired with comparable accuracy in exposure detection could prove toenail samples to be a preferred biomarker for many studies. Current elemental quantification techniques in toenail samples could be improved. The standard practice for measuring metal exposure in toenails, inductively coupled plasma mass spectrometry (ICP-MS), has a counterpart in x-ray fluorescence. While maintaining similar quantification capabilities, x-ray fluorescence could provide decreased cost, preservation of samples, and ease of operation. Portable XRF machines have been tested for measuring toenail samples, but they have drastically increased detection limits in comparison to ICP-MS. New benchtop XRF systems should give comparable detection limits to ICP-MS. This study compares the benchtop XRF measurements of lead (Pb), copper (Cu), iron (Fe), and Selenium (Se) levels to that of ICP-MS measurements of toenail samples and calculates estimated detection limits for 23 other elements. We found strong correlations for the toenail lead (R2 = 0.92), copper (R2 = 0.95), selenium (R2 = 0.60), and iron (R2 = 0.77) comparison between desktop XRF and ICP-MS measurements. Median minimum detection limits over the 23 elements were found to be 0.2 µg/g using a 7.5-min measurement. Benchtop XRF provides a lower detection limit than previously studied portable XRF machines, which gives it the capability of accurately detecting almost any desired element in nail samples. Benchtop XRF provides a non-destructive alternative to ICP-MS in surveillance of nail samples.

The fate of Cu and Zn along the feed-animal-excreta-effluent continuum in swine systems according to feed and effluent treatment strategies.

Copper (Cu) and zinc (Zn) have negative environmental impacts as they accumulate in the soil after pig manure is spread. Cu and Zn are essential elements in pig nutrition but due to their low retention rate, more than 90% of ingested Cu and Zn are excreted. A better understanding of the behaviour of these elements throughout the animal-manure-soil continuum according to feed composition and manure management chain is thus required to propose alternative ways to reduce these environmental impacts. The aim of this study was to determine the fate of Cu and Zn throughout this continuum by studying the effect of Cu and Zn contents in animal feed and in the manure management chain based on anaerobic digestion and composting. Faeces were collected from 24 finishing pigs fed with 4 different Cu and Zn dietary levels and sources of supplementation. Samples of faeces were exposed to mesophilic anaerobic digestion or to 5-week composting with straw. Concentrations of Cu and Zn in the faeces were highly dependent on dietary supplies and ranged from 38 to 188 mg Cu/kg DM and from 191 to 728 mg Zn/kg DM. Degradation of a significant fraction of organic matter during treatment led to a significant increase in Cu and Zn concentration relative to the product's dry matter (DM) content, which. Cu and Zn concentrations relative to DM content were twice as high after treatment whatever the content and the form of Cu and Zn dietary supplementation. Otherwise, effluent treatment tended to reduce the possible availability of Cu and Zn in final organic products according to water-extractible contents. This study clearly shows that feed management is the main lever for reducing the amount of Cu and Zn amount in pig effluents and hence in the soil. Appropriate treatment could also facilitate the supply of organic fertilisers to areas with soil deficiency, but feed strategies need to be adapted to the treatment chain to enable the production of good quality organic products that respect EU regulations.

Determination of copper in rose tea samples using flame atomic absorption spectrometry after emulsification liquid-liquid microextraction.

Rose tea infusion has gained popularity worldwide due to its health benefits. However, it is known that tea plants can be contaminated with heavy metals including copper. Hence, an accurate and applicable analytical method namely emulsification liquid-liquid microextraction based deep eutectic solvent - flame atomic absorption spectrometry (ELLME-DES-FAAS) was proposed to determine copper at trace levels in rose tea samples. Under the optimum experimental conditions, analytical figures of merit for the developed method were examined, and dynamic range, limit of detection (LOD) and limit of quantification (LOQ) were found to be 5.07-246.61 µg/kg (mass-based) with 0.9992 coefficient of determination, 2.50 µg/kg and 8.32 µg/kg, respectively. A matrix matching calibration strategy was employed to boost recovery results, and the acceptable recovery results were recorded between 95.9 % and 118.4 %. According to recovery results, the developed analytical method can be safely employed to determine the concentration of copper in rose tea samples accurately.

Spatial distribution of trace metals and associated transport proteins during bacterial infection.

Innate immune systems alter the concentrations of trace elements in host niches in response to invading pathogens during infection. This work reports the interplay between d-block metal ions and their associated biomolecules using hyphenated elemental techniques to spatially quantify both elemental distributions and the abundance of specific transport proteins. Here, lung tissues were collected for analyses from naïve and Streptococcus pneumoniae-infected mice fed on a zinc-restricted or zinc-supplemented diet. Spatiotemporal distributions of manganese (55Mn), iron (56Fe), copper (63Cu), and zinc (66Zn) were determined by quantitative laser ablation-inductively coupled plasma-mass spectrometry. The murine transport proteins ZIP8 and ZIP14, which are associated with zinc transport, were also imaged by incorporation of immunohistochemistry techniques into the analytical workflow. Collectively, this work demonstrates the potential of a single instrumental platform suitable for multiplex analyses of tissues and labelled antibodies to investigate complex elemental interactions at the host-pathogen interface. Further, these methods have the potential for broad application to investigations of biological pathways where concomitant measurement of elements and biomolecules is crucial to understand the basis of disease and aid in development of new therapeutic approaches.

Determination of copper ion at trace levels in apple tea samples by simultaneous complexation and spray assisted microextraction method prior to detection by flame atomic absorption spectrophotometry.

In the present study, a green and sensitive analytical method for the determination of copper ion at trace levels in apple tea samples was developed. Simultaneous complexation/extraction of the analyte were achieved by spraying-based fine droplet formation liquid-phase microextraction (SFDF-LPME). Copper ion was complexed with a Schiff base chelating agent called as N,N'-Bis(salicylidene)-1,2-phenylenediamine (BSP). Under the optimum conditions, the developed SFDF-LPME-FAAS and FAAS system were assessed with respect to limit of detection (LOD), limit of quantitation (LOQ), linearity and percent relative standard deviation (%RSD). LOD and LOQ values for SFDF-LPME-FAAS method were found to be 6.0 and 19.9 µg/kg, respectively. Enhancement in calibration sensitivity for developed method was found as 23 folds. In addition, accuracy/suitability of the developed SFDF-LPME-FAAS method were confirmed by spiking experiments. Two different apple tea samples were spiked to different concentration values and percent recovery results from 91.1 and 123.8 % proved the accuracy/suitability of the method.

Analysis of the coupled flows of aluminum and copper in household air conditioning system.

The global "copper-poor and aluminum-rich" situation has made the possibility of "copper saving with aluminum" an important topic. This study established a framework for analyzing multiple substances' coupled flows at the product level based on material flow analysis (MFA), and took the household air conditioning system of the Chinese mainland in 2020 as an example to characterize the coupled flows of aluminum and copper. The results showed that the system consumed 0.69 million tons of aluminum and 2.10 million tons of copper, and discharged 0.17 million tons of aluminum and 0.43 million tons of copper to the environment cumulatively to achieve 13.2 million terajoules of final heat exchanged and serve 1.24 billion square meters during lifetime in mainland China alone, secondary aluminum and copper accounted for only 22.61% and 24.83% of the total consumption, and the in-use stocks increased by 0.19 million tons of aluminum and 0.70 million tons of copper. The external dependency of copper ore was 92.83%, which was significantly higher than the 44.29% of bauxite. The comprehensive utilization efficiency of copper reached 77.88%, which was slightly higher than the 70.80% of aluminum. The conclusion indicates that under the premise of meeting use requirements, promoting "replacing copper with aluminum" can improve the stability and safety of China's material supply chain, but there is a need to further boost the production efficiency of aluminum in primary production.

Hair Zinc and Chromium Levels Were Associated with a Reduced Likelihood of Age Related Cognitive Decline in Centenarians and Oldest-Old Adults.

BACKGROUND: Cognitive function has inevitable decline with advancing age in nature, and age-related cognitive decline (ARCD) is of increasing concern to aging population. Scarce study has involved the associations between hair trace elements and ARCD in older adults, especially in centenarians and oldest-old adults. This study was to investigate the associations between hair trace elements and ARCD in centenarians and oldest-old adults. METHODS: Based on the household registration information of centenarians and oldest-old adults provided by the Civil Affairs Department of Hainan Province, China, the investigators conducted a one-to-one household survey among centenarians (≥100 years old) and oldest-old adults (80-99 years old). All 50 centenarians had a median age of 103 years and females accounted for 68.0%. All 73 oldest-old adults aged 80-99 years had a median age of 90 years and females accounted for 82.2%. Basic information were obtained with questionnaire interview, physical examination, biological test and hair collection by pre-trained local doctors and nurses. An inductively coupled plasma mass spectrometer was used to measure hair trace elements. All data in this study comes from China. Age, sex, body mass index, systolic blood pressure, diastolic blood pressure, smoking, drinking, hemoglobin, albumin, fasting blood pressure, zinc, chromium, copper, selenium, iron, manganese, strontium, lead, magnesium, potassium, and barium were simultaneously included in multivariate Logistic regression analysis. One adjusted model was done with all hair trace elements together. RESULTS: Zinc and chromium levels were significantly lower in participants with ARCD than those without ARCD (P < 0.05 for all). Multivariate Logistic regression analysis indicated that zinc [odds ratio (OR): 0.988, 95%confidence interval (95%CI): 0.977-0.999] and chromium (OR: 0.051, 95%CI: 0.004-0.705) were associated with a reduced likelihood of ARCD (P < 0.05 for all). CONCLUSIONS: Hair zinc and chromium levels were associated with a reduced likelihood of ARCD in centenarians and oldest-old adults. Further studies are necessary to verify if zinc and chromium supplementation has the potential to improve cognitive function and prevent ARCD development.

Trace elements status in human breast milk of mothers from Île-de-France region.

Breastfeeding is the main source of nutrition during first months of life. Its composition varies according to parameters like mother's diet and health, living area, number of pregnancies and lactation duration… Trace-elements concentration in breastmilk is then an important parameter that can affect infant's health, growth or immune system and organ functions. Few data are available on this topic, and results are often very variable. The aim of this work is to determine reference values of Copper (Cu), Zinc (Zn), Selenium (Se), Cobalt (Co), Iron (Fe) and Iodine (I) in human breastmilk according to lactation duration and to study influencing parameters on its elementary composition. Regional Human Milk Bank of Necker Enfants Malades Hospital provided samples that came from breastfeeding woman involved in voluntary milk donation and epidemiologic data. Two hundred thirty-two breastmilk were analysed. After nitric acid mineralization of milk samples, Cu, Zn, Se, Co and I were determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in a standard mode. Fe was measured by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Both assays were validated in terms of sensitivity, repeatability and accuracy.Studied breast milks came from mothers with an average age of 32 years and donation time ranged from one day after childbirth to 974 days (> 2.5 years); mean lactation duration is 59 days (> 8 weeks) while median duration is 29 days (around 4 weeks). In all studied samples, mean results and reference values are for Cu: 6.02 (1.71-13.23), Zn: 43.86 (7.3-107.0), Se: 0.12 (0.07-0.24), I: 0.29 (0.07-1.01) and Fe: 4.72 (1.25-11.49) µmol/L and for Co: 12.28 (5.27-25.82) nmol/L. Important number of studied milks allowed their distribution into seven classes of lactation durations. Samples were divided into four successive classes of fifteen days after childbirth, two other classes corresponding to the 3rd and 4th months and a last class for milks sampled after 4 months of lactation. Results were analysed in each class allowing study of evolution during lactation. That was particularly interesting for Zn, that presented an important variability in the total population (4-132 µmol/L) explained by variation along lactation evolution decreasing from 48 to 17 µmol/L in first and last duration classes respectively. In addition, Cu and Fe concentrations were also significantly correlated with lactation duration while Se and I were in a lesser extent (p = 0.002). In this study, we present reference values for studied trace elements at different lactation stages, allowing a fine interpretation of future breast milk samples results according to their sampling time. By continuing this study, we plan to increase number of samples in some of the classes and to study the influence of premature birth or twin pregnancy on breast milk elementary composition.

Nutritional values of wild edible freshwater macrophytes.

Background: The social acceptability of wild freshwater macrophytes as locally consumed vegetables is widespread. Freshwater macrophytes have several uses; for example, they can be used as food for humans. This study determined the proximate composition and mineral content of three freshwater macrophyte species, i.e., Eichhornia crassipes, Limnocharis flava, and Neptunia oleracea. Methods: Young shoots of E. crassipes, L. flava, and N. oleracea were collected from shallow channels of Puchong (3°00'11.89″N, 101°42'43.12″E), Ladang 10, Universiti Putra Malaysia (2°58'44.41″N, 101°42'44.45″E), and Kampung Alur Selibong, Langgar (06°5'50.9″N, 100°26'49.8″E), Kedah, Peninsular Malaysia. The nutritional values of these macrophytes were analysed by using a standard protocol from the Association of Official Analytical Chemists. Eight replicates of E. crassipes and L. flava and four replicates of N. oleracea were used for the subsequent analyses. Results: In the proximate analysis, N. oleracea possessed the highest percentage of crude protein (29.61%) and energy content (4,269.65 cal g-1), whereas L. flava had the highest percentage of crude fat (5.75%) and ash (18.31%). The proximate composition trend for each species was different; specifically, all of the species possessed more carbohydrates and fewer crude lipids. All of the species demonstrated a similar mineral trend, with high nitrogen and potassium and lower copper contents. Nitrogen and potassium levels ranged from 12,380-40,380 mg kg-1 and from 11,212-33,276 mg kg-1, respectively, and copper levels ranged from 16-27 mg kg-1. The results showed that all three plant species, i.e., E. crassipes, N. oleracea, and L. flava are plant-based sources of macro- and micronutrient beneficial supplements for human consumption.

Effects of Diabetes on Elemental Levels and Nanostructure of Root Canal Dentin.

INTRODUCTION: This study evaluated the effects of diabetes mellitus (DM) on the nanostructure of root canal dentin using high-resolution transmission electron microscopy (HRTEM) and inductively coupled plasma mass spectrometry (ICP-MS). METHODS: Twenty extracted human premolars from diabetic and nondiabetic patients (n = 10 in each group) were decoronated and sectioned horizontally into 40 2-mm-thick dentin discs, with each disc designated for a specific test. ICP-MS was used to determine the different elemental levels of copper, lithium, zinc, selenium, strontium, manganese, and magnesium in diabetic and nondiabetic specimens. HRTEM was used to analyze the shape and quantity of the apatite crystals in diabetic and nondiabetic dentin at the nanostructural level. Statistical analysis was performed using Kolmogorov-Smirnov and Student t test (P < .05). RESULTS: ICP-MS revealed significant differences in trace element concentrations between the diabetic and nondiabetic specimens (P < .05), with lower levels of magnesium, zinc, strontium, lithium, manganese, and selenium (P < .05), and higher levels of copper in diabetic specimens (P < .05). HRTEM revealed that diabetic dentin exhibited a less compact structure with smaller crystallites and significantly more crystals in the 2500 nm2 area (P < .05). CONCLUSION: Diabetic dentin exhibited smaller crystallites and altered elemental levels more than nondiabetic dentin, which could explain the higher root canal treatment failure rate in diabetic patients.

Effect of Organic Selenium on the Homeostasis of Trace Elements, Lipid Peroxidation, and mRNA Expression of Antioxidant Proteins in Mouse Organs.

(1) In this study we determined the effect of long-term selenomethionine administration on the oxidative stress level and changes in antioxidant protein/enzyme activity; mRNA expression; and the levels of iron, zinc, and copper. (2) Experiments were performed on 4-6-week-old BALB/c mice, which were given selenomethionine (0.4 mg Se/kg b.w.) solution for 8 weeks. The element concentration was determined via inductively coupled plasma mass spectrometry. mRNA expression of SelenoP, Cat, and Sod1 was quantified using real-time quantitative reverse transcription. Malondialdehyde content and catalase activity were determined spectrophotometrically. (3) After long-term SeMet administration, the amount of Se increased by 12-fold in mouse blood, 15-fold in the liver, and 42-fold in the brain, as compared to that in the control. Exposure to SeMet decreased amounts of Fe and Cu in blood, but increased Fe and Zn levels in the liver and increased the levels of all examined elements in the brain. Se increased malondialdehyde content in the blood and brain but decreased it in liver. SeMet administration increased the mRNA expression of selenoprotein P, dismutase, and catalase, but decreased catalase activity in brain and liver. (4) Eight-week-long selenomethionine consumption elevated Se levels in the blood, liver, and especially in the brain and disturbed the homeostasis of Fe, Zn, and Cu. Moreover, Se induced lipid peroxidation in the blood and brain, but not in the liver. In response to SeMet exposure, significant up-regulation of the mRNA expression of catalase, superoxide dismutase 1, and selenoprotein P in the brain, and especially in the liver, was determined.

Effect of feed trace elements on eggs of five strains of laying hens and their health risk assessment.

BACKGROUND: Trace elements are essential for human nutrition, and their deficiencies or excesses are strongly associated with several diseases, such as cardiovascular ones. OBJECTIVES: The current cross-sectional study investigated the concentration of essential trace elements (copper, non-metal selenium, iron, zinc, cobalt and manganese) in eggs and diets of five strains of laying hens. METHODS: The yolk and albumen were analysed separately, and wet preparation was carried out following inductively coupled plasma-optical emission spectrometry detection. The target hazard quotients (THQs) for the non-carcinogenic disease were calculated by the United States environmental protection agency (USEPA) method. RESULTS: The highest concentrations of selenium, zinc and manganese were found in egg yolks of native hens (0.76, 44.22 and 6.52 mg/kg, respectively). The highest amounts of copper and cobalt were recorded in the egg yolk of Lohman (2.07 and 0.023 mg/kg, respectively). On the other hand, the egg yolk of Bovans contained the highest amount of iron (57.46 mg/kg). CONCLUSION: Overall, the potential health risks were minimal, and the consumption of eggs was generally safe.

Ecological risk assessment of potentially toxic elements in selenium-rich soil with different land-use types.

Dashan Village area is one of the representative areas in China with high selenium concentration in the natural environment. A total of 133 topsoil samples have been collected in the Dashan Village area to explore the potential toxic elements (PTEs) background concentrations in soils under different land-use types for a comprehensive PTEs risk assessment (arsenic, cadmium, chromium, copper, mercury, nickel, lead, selenium and zinc). The results show that the geometric mean concentrations of As, Cr, Cu, Hg, Ni, Pb, Se and Zn found in the soil of the Dashan Village area were lower than the control standard for soil contamination risk in agricultural land. However, the geometric mean concentrations of Cd exceeded their corresponding standard values. For different land-use types, geometric mean concentrations of As, Cd, Cu, Hg, Ni and Pb in the arable soils were higher than in woodland soils and tea garden soils. Based on the potential ecological risk assessment, the woodland, arable and tea garden were at low-risk levels. Cadmium posed the highest ecological risk, while the other PTEs were of low risk in soils. Multiple statistical analyses and geostatistical analysis indicated that the concentrations of Cr, Ni, Pb, Cu, Zn and Se originated mainly from natural sources, while the concentrations of Cd, As and Hg could be influenced by anthropogenic activities. These results provide scientific support for the safe utilization and ecological sustainability of selenium-rich land resources.

Keggin type phosphotungstic acid intercalated copper-chromium-layered double hydroxide reinforced porous hollow fiber as a sorbent for hollow fiber solid phase microextraction of selected chlorophenols besides their quantification via high performance liquid chromatography.

Herein, a copper-chromium-layered double hydroxide (Cu/Cr-LDH) was synthesized by the co-precipitation method. The Cu/Cr-LDH was intercalated to the Keggin-type polyoxometalate (H3PW12O40). The modified LDH accommodated in the pores of hollow fiber (HF), to prepare the extracting device for the HF-solid phase microextraction method (HF-SPME). The method was used for the extraction of 4-chlorophenol, 2,4-dichlorophenol, and 2,4,6- trichlorophenol from tap water, river water, and tea sample. The extracted target analytes were quantified via high-performance liquid chromatography-UV detection. The figures of merit of the method such as, linear dynamic ranges (LDRs), limit of detections (LODs) and, limit of quantifications (LOQs), were determined based on the obtained optimum condition. Based on the results, the LDR was between 1 and 500 µg L - 1 and r2 higher than 0.9960. The LODs and LOQs were obtained in the ranges of 0.28-0.36 µg L - 1 and 0.92-1.1 µg L - 1, respectively. The relative standard deviations ((RSDs% for inter-and intra-day) of the method for the extraction of target analytes were calculated in two different concentrations of (2 and 10 µg L - 1) and (5 and 10 µg L - 1) between 3.70% - 5.30% and 3.50% - 5.70%-respectively. The enrichment factors were obtained between 57 and 61. In order to investigate the accuracy of the method, also the relative recovery was obtained, between 93 and 105%. Finally, the proposed method was used for the extraction of the selected analytes in different water and tea samples.

Potential larvicidal bioefficacy of copper sulfide-based hybrid nanoemulsions of eucalyptus oil against Aedes aegypti (Linnaeus).

BACKGROUND & OBJECTIVES: Nanotechnology, an emerging field, has acquired considerable attention for the control of vectors. The present study aimed to synthesize, characterize copper sulfide- and eucalyptus oil-based hybrid nanoemulsions and investigate their larvicidal potential against Aedes aegypti by studying larvicidal bioassay, morphological aberrations, histopathological alterations, biochemical analysis and evaluation of risk assessment in non-target organisms. METHODS: Hybrid nanoemulsions were prepared by mixing aqueous copper sulfide nanoparticles (CuSNPs) with non-polar eucalyptus oil in five ratios (1:1, 1:2, 1:3, 1:4 and 1:5) by sonication, screened and characterized using Transmission electron microscopy (TEM). Larvicidal activity was recorded and toxicity values were calculated by log-probit method. Morphological, histological and biochemical changes were examined in Aedes aegypti larvae after treatment. Nanohybrids were also tested under simulated conditions and against non-target organism. RESULTS: The nanohybrid ratio of 1:5 was found to be stable after thermodynamic stability tests. TEM studies revealed average size of 90±7.90 nm with globular shape. LC50 and LC90 toxicity values of prepared CuSNPs were calculated out to be 5.00 and 5.81ppm after 24 hours treatment. Effective concentration of prepared nanohybrid (6.5ppm) tested under simulated conditions showed maximum larvicidal mortality after 48 hours of exposure. No toxicity towards the Mesocyclops spp. was observed after treatment of these nanohybrids even up to 21 days. INTERPRETATION & CONCLUSION: Copper sulfide based hybrid nanoemulsions were found to show efficient larvicidal property which can be used for the formulation of ecofriendly bio-larvicide against Aedes aegypti.

A sensitive fluorescence sensor based on a glutathione modified quantum dot for visual detection of copper ions in real samples.

Copper (Cu2+), as a heavy metal, accumulates in the human body to a certain extent, which can induce various diseases and endanger human health. Rapid and sensitive detection of Cu2+ is highly desired. In present work, a glutathione modified quantum dot (GSH-CdTe QDs) was synthesized and applied in a "turn-off" fluorescence probe to detect Cu2+. The fluorescence of GSH-CdTe QDs could be rapidly quenched in the presence of Cu2+ through aggregation-caused quenching (ACQ), resulting from the interaction between the surface functional groups of GSH-CdTe QDs and Cu2+ and the electrostatic attraction. In the range of 20-1100 nM, the Cu2+ concentration showed a good linear relationship with the fluorescence decline of the sensor, and the LOD is 10.12 nM, which was lower than the U.S. Environmental Protection Agency (EPA) defined limit (20 µM). Moreover, aiming to attain visual analysis, colorimetric method was also used for rapidly detecting Cu2+ by capturing the change in fluorescence color. Interestingly, the proposed approach has successfully been applied for the detection of Cu2+ in real samples (i.e., environment water, food and traditional Chinese medicine) with satisfactory results, which provides a promising strategy for the detection of Cu2+ in practical application with the merits of being rapid, simple and sensitive.