Microwave Plasma Atomic Emission Spectrometry Research Articles

High-Throughput Silica Nanoparticle Detection for Quality Control of Complex Early Life Nutrition Food Matrices.

The addition of nanomaterials to improve product properties has become a matter of course for many commodities: e.g., detergents, cosmetics, and food products. While this practice improves product characteristics, the increasing exposure and potential impact of nanomaterials (<100 nm) raise concerns regarding both the human body and the environment. Special attention should be taken for vulnerable individuals such as those who are ill, elder, or newborns. But detecting and quantifying nanoparticles in complex food matrices like early life nutrition (ELN) poses a significant challenge due to the presence of additional particles, emulsion-droplets, or micelles. There is a pressing demand for standardized protocols for nanoparticle quantification and the specification of "nanoparticle-free" formulations. To address this, silica nanoparticles (SiNPs), commonly used as anticaking agents (AA) in processed food, were employed as a model system to establish characterization methods with different levels of accuracy and sensitivity versus speed, sample handling, and automatization. Different acid treatments were applied for sample digestion, followed by size exclusion chromatography. Morphology, size, and number of NPs were measured by transmission electron microscopy, and the amount of Si was determined by microwave plasma atomic emission spectrometry. This successfully enabled distinguishing SiNP content in ELN food formulations with 2-4% AA from AA-free formulations and sorting SiNPs with diameters of 20, 50, and 80 nm. Moreover, the study revealed the significant influence of the ELN matrix on sample preparation, separation, and characterization steps, necessitating method adaptations compared to the reference (SiNP in water). In the future, we expect these methods to be implemented in standard quality control of formulation processes, which demand high-throughput analysis and automated evaluation.

Compliance Level and Stability of Micronutrients in Fortified Maize Flour in Tanzania.

Maize flour fortification was introduced in Tanzania in 2011 to address the risk of micronutrient deficiency to children, adolescents, and women of childbearing age. Fortified maize flours are processed by small-scale processors who are exempted from mandatory fortification. The current study is aimed at assessing the compliance and stability of fortified processed maize flour with zinc, iron, and folic acid by small-scale processors in comparison to the recommended Tanzania national standards (TZS 328). A total of 69 samples of fortified maize flour were collected at the point of production and retail outlets in Dar es Salaam and Morogoro municipalities, Tanzania. Micronutrients (zinc and iron) were analysed using microwave plasma atomic emission spectrometry (MP-AES), and folic acid was analysed using high-performance liquid chromatography (HPLC). The mean concentrations of micronutrient were significantly (p < 0.05) higher at the production site compared to the retail outlet. The amount of iron, zinc, and folic acid in the samples at the production site was 27.17 ± 1.63 mg/kg, 30.56 ± 2.01 mg/kg, and 0.69 ± 0.02 mg/kg, respectively, while it was 19.34 ± 0.97 mg/kg, 21.71 ± 1.50 mg/kg, and 0.49 ± 0.02 mg/kg for iron, zinc, and folic acid, respectively, at the retail outlets. Only 31.6% of the assessed samples from production and 12.9% from retail outlets complied with the recommended national standard. The stability of iron, zinc, and folic acid for the fortified maize flour stored at room temperature (20-32°C) for six months was 95.8%, 96.9%, and 66.9%, respectively. Further investigation on the consistency performance of the dosifier and consistency training of working in the processing unit on the requirements of fortification standards should be done.

Evaluation of the Safety and Potential Benefits of Beetroot-Based Dietary Supplements According to Their Elemental Composition

The study aimed to assess the health value and safety associated with the consumption of the chosen 37 beetroot-based dietary supplements (DSs). An optimized and validated analytical procedure, using a method called microwave plasma atomic emission spectrometry (MP-AES), was developed to determine the profiles of 19 elements (Na, K, Fe, Ca, Pt, Zn, Cd, Cu, V, Co, Ni, Pb, Mo, Mg, Al, Mn, Sr, Cr, Ba) in the DSs. The products were assessed for compliance with the recommended daily doses for the chosen elements, and any deviations were identified. Results showed that powders constituted a richer source of elements than capsules and tablets. The exception was iron-enriched products, which provided the highest dose of Fe (3.75 to 25 mg/daily dose). Safety assessment was evaluated in 3 steps, including (1) the determination of levels of Al, Ba, Cd, and Pb; (2) comparison of their content with the permissible contamination limits; and (3) comparison of the weekly or monthly intake of Al and Cd with the provisional tolerable weekly (PTWI) or monthly (PTMI) intake, respectively. The content of Ba was evaluated because of the oral reference dose (RfD). Five products were significantly contaminated with Cd (4–134% of PTMI Cd), two with Al (11–12%), and three with Ba (1.085–1.331 µg/d.d.). Lead was not detected above the LOQ (0.035 mg/kg). Factor analysis was employed to differentiate between the pharmaceutical forms (capsules, tablets, and powders) and determine the origin of the powder contained in the capsules. These results highlight the importance of implementing more stringent control measures and regulatory changes in the DSs market to ensure consumer safety.

Metallomics as an Essential Analytical Tool for the Development of Potential Metallodrugs

Metallomics is an emerging area of the omics disciplines that has grown enormously since its conception as an academic discipline in 2004. This discipline integrates research related to biometals, along with other disciplines such as genomics, proteomics, metabolomics, and bioinorganic chemistry. It is defined as the study of the metallome, the interactions and functional connections of metal ions or species with genes, proteins, metabolites, and other biomolecules in biological systems. The study of the metallome of a species can provide information on the distribution of an element between cellular compartments, on the coordination environment in which a biomolecule is incorporated, or on the concentration of individual metal species present. In this regard, it plays a very important role in providing integrated information that connects metallomics with other omics disciplines.1,2 The term ‘metallomics’ was pronounced for the first time in June 2002 during the Tokushima Seminar on Chemical Engineering held in Tokushima, Japan, where the development of this new omics discipline was suggested, which was closely influenced by the progress of Analytical Atomic Spectrometry, in particular by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). Since the mid-1970s, ICP-MS and ICP-AES techniques have been positioned as highly sensitive analytical tools with excellent possibilities for simultaneous quantification of multiple elements. Nowadays, it is possible to carry out analyses of basically all the elements in any type of sample using one of these two techniques. Likewise, the use of several other techniques for metallomic studies has been reported, such as Electrothermal Atomic Absorption Spectrometry (ETAAS), Microwave Plasma Atomic Emission Spectrometry (MP-AES), Laser Induced Plasma Spectroscopy (LIBS), and Energy Dispersive X-Ray Fluorescence Spectrometry (EDXRF), among others.2 A very useful bioanalytical study, within the field of metallomics, is the cellular uptake assay of potential metallodrugs. Using an adequate analytical technique, the metallic center of a given metallodrug can be monitored, and thus the fraction capable of entering a certain type of cell can be evaluated. Likewise, the distribution at the subcellular level and the association of the studied metallodrug with biomacromolecules of interest may be studied. In this context, our research group has been working on the optimization and validation of different bioanalytical methods for monitoring potential metallodrugs with activity against Trypanosoma cruzi, a protozoan parasite that causes Chagas disease, which is a pressing health problem in high-poverty areas of Latin America.3 A large number of metallic compounds with anti-Trypanosoma cruzi activity have been synthesized by our group, using as a strategy the coordination of metal ions or organometallic centers of pharmacological importance with bioactive organic ligands that have proven activity against Trypanosoma cruzi. Binding to metal can modify properties such as the solubility, lipophilicity, stability, and electronic and transport properties of the organic ligand, generating compounds that may be more active and/or less toxic. These metallic compounds can act by affecting two or more targets in the parasite: the ligand itself and others resulting from the presence of the metal. The biological properties of the metal–bioactive ligand compound will depend on the nature of the metallic center and the bioactive ligand, the presence of other ligands, and, fundamentally, its physicochemical-structural properties. In this regard, our group has focused its attention on the rational design of antiparasitic metallic compounds based on the relationships between chemical structure, physicochemical properties, and biological activity. This research line has led to important contributions that have been transferred to the scientific field, showing the vital importance of cellular uptake metallomic studies to understand the fate of potential metallodrugs and elucidate targets and mechanisms of action. In this context, the potential as an antitrypanosomal agent of a new rhenium(I) tricarbonyl compound with the formula fac-[Re(I)(CO)3(tmp)(CTZ)](PF6), where CTZ = clotrimazole and tmp = 3,4,7,8-tetramethyl-1,10-phenanthroline, was recently evaluated. It showed very good activity against the epimastigote form of Trypanosoma cruzi, with IC50 values (half maximal inhibitory concentration) in the low micromolar range. For this task, a new bioanalytical method based on the MP-AES technique was developed and validated.3 This technique has reemerged in the last few years with several improvements and can be considered as a good strategy for the determination of highly refractory elements such as rhenium. The method was applied to the determination of the percentage of rhenium taken up by the parasites and the association of the compound with the main biomacromolecules: soluble proteins, insoluble fraction, DNA, and RNA. The results of the metallomic study showed a low percentage of total rhenium taken up by the parasites, around 1 %, and a preferential accumulation in the soluble protein fraction, around 83 %. Also, the low localization of the compound in the DNA and RNA fractions, less than 1 %, made it possible to discard these biomolecules as the main targets of action. The developed method turned out to be an economical and efficient alternative for metallomic studies of potential rhenium metallodrugs, applied for the first time for the analysis of this particular element.3 In order to deepen in the localization of the compound taken up in the whole parasite, confocal Raman microscopy was performed.4 However, the main bands of the rhenium(I) tricarbonyl compound showed a strong overlap with signals coming from lipids, proteins, and DNA from the parasite, and due to the low concentration assayed, signals associated with ν(CO) could not be detected. Notwithstanding that, the overlap found by confocal Raman spectroscopy gave us a clue to the actual location of the compound inside the parasite, constituting an interesting indirect metallomic tool.4 Similar bulk studies were previously carried out by our research group using the ETAAS technique. For this task, novel bioanalytical methods were developed and validated, which were successfully applied to study the cellular uptake of potential palladium, platinum, and vanadium metallodrugs against Trypanosoma cruzi.5,6 This example of interdisciplinary work highlights the importance of developing and validating bioanalytical methods such as metallomic strategies to carry out cellular uptake studies, in order to assess the fate and possible targets and mechanisms of action of potential metallodrugs. Likewise, they promote the key role of Bioanalytical Chemistry in supporting Medicinal Inorganic Chemistry during the development of new potential metallodrugs, in the search for answers to important Public Health issues.

Fractionation of selenium isotopes during biofortification of Saccharomyces cerevisiae and the influence of metabolic labeling with 15N.

Isotope fractionation of metals/metalloids in biological systems is an emerging research area that demands the application of state-of-the-art analytical chemistry tools and provides data of relevance to life sciences. In this work, Se uptake and Se isotope fractionation were measured during the biofortification of baker's yeast (Saccharomyces cerevisiae)-a product widely used in dietary Se supplementation and in cancer prevention. On the other hand, metabolic labeling with 15N is a valuable tool in mass spectrometry-based comparative proteomics. For Se-yeast, such labeling would facilitate the assessment of Se impact on yeast proteome; however, the question arises whether the presence of 15N in the microorganisms affects Se uptake and its isotope fractionation. To address the above-mentioned aspects, extracellularly reduced and cell-incorporated Se fractions were analyzed by hydride generation-multi-collector inductively coupled plasma-mass spectrometry (HG MC ICP-MS). It was found that extracellularly reduced Se was enriched in light isotopes; for cell-incorporated Se, the change was even more pronounced, which provides new evidence of mass fractionation during biological selenite reduction. In the presence of 15N, a weaker preference for light isotopes was observed in both, extracellular and cell-incorporated Se. Furthermore, a significant increase in Se uptake for 15N compared to 14N biomass was found, with good agreement between hydride generation microwave plasma-atomic emission spectrometry (HG MP-AES) and quadrupole ICP-MS results. Biological effects observed for heavy nitrogen suggest 15N-driven alteration at the proteome level, which facilitated Se access to cells with decreased preference for light isotopes.

Food-mediated exposure of Hofmeister ions in Oryza sativa (Rice) from selected CKDu endemic regions in Sri Lanka.

The objectives of this study were to determine selected Hofmeister anions and cations that are important for kidney health, in raw rice samples from selected Chronic Kidney Disease of unknown etiology (CKDu) endemic and non-endemic areas in Sri Lanka and their intake. The anions and cations were analyzed by Ion Chromatography and Microwave Plasma Atomic Emission Spectrometry (MP-AES), respectively, after alkaline and acid digestion in thirty raw rice samples each from CKDu endemic and non-endemic areas, and the dietary intake was estimated. The mean concentrations of fluoride (F-), chloride (Cl-), phosphate (PO43-), sulfate (SO42-), sodium (Na+), magnesium (Mg2+), potassium (K+), and calcium (Ca2+) in raw rice in CKDu endemic areas were 53.317, 1515.3, 2799.6, 2704.9, 30.603, 300.76, 1001.3, and 90.075mg/kg, respectively. The mean concentration of the anions and cations in raw rice from CKDu non-endemic areas were 22.850, 947.52, 4418.7, 6080.2, 23.862, 364.45, 955.78, and 96.780mg/kg, respectively. Significantly higher differences (p < 0.05) were reported in the mean concentration of F-, Cl-, and Na+ in raw rice from CKDu endemic areas in comparison with the samples from non-endemic areas. The aggregated estimated daily intake (EDI) and cumulative EDI of F- via consumption of cooked non-traditional samba rice from CKDu endemic areas for adults were the highest (0.155 and 0.172mg/kg bw/d, respectively), which were higher than the recommended tolerable upper intake value (0.15-0.2mg/kg bw/d). In contrast, the traditional rice from CKDu non-endemic areas for adolescents, reported the lowest values (0.0210 and 0.0470mg/kg bw/d, respectively). Adults who consume non-traditional samba rice from CKDu endemic areas were at health risk, while children were the most vulnerable group due to their low body weight. These results indicate that the consumption of rice rich in Hofmeister ions may contribute to the total intake and act as risk factors to negatively affect weak kidneys in CKDu endemic areas. Further research to analyze Hofmeister ions in cooked rice and rice from different countries is recommended.

Formulation and Evaluation of Iron-Rich Chocolate Spread from Sugarcane Syrup and Sunflower Seeds

Anemia is widely recognized as a serious public health problem and the most common type of micronutrient deficiency globally. Developing a product enriched with iron to overcome this issue has received excessive attention. For this purpose, sugarcane syrup and sunflower seeds were utilized as sugar and hazelnut substitutes in chocolate spread production. Four formulations were created and assessed for their chemical, texture, and sensory attributes, as well as their iron content by microwave plasma-atomic emission spectrometry (MP-AES) and compared with a commercial product. Fat and sugar levels were reduced by 2−1.3 and 1–1.5 times, respectively, in the samples. Increasing the percentage of sugarcane syrup raised the iron content 3- to 6-fold. Peroxide and free fatty acid values indicate that iron negatively affects the oil quality of the developed samples. The samples could be recommended as novel products that are preferred as a healthy and low-cost chocolate spread.

Comparative verification of Mehlich 3 soil analysis methods in Northern Mozambique using microwave plasma–atomic emission spectrometry

ABSTRACT Regular testing of nutrients in soil samples is important for understanding soil fertility. This study investigated a combination of the Mehlich 3 extraction method and Microwave Plasma-Atomic Emission Spectrometry (MP – AES) for testing the nutrient status in soil to establish a labor-saving and cost-effective analytical method in Northern Mozambique. Available P, exchangeable cations, and micronutrients in the Mehlich 3 extract were measured using conventional methods and compared with those quantified using MP – AES to determine its accuracy. Linear regression analysis implied a high correlation between the Available P extracted via Mehlich 3 and quantified using MP – AES and that extracted via Mehlich 3, Bray 1, Olsen, and Mehlich 1 and quantified using UV – Vis. Moreover, a high determination coefficient (R2 = 0.920) was observed between Mehlich 3 quantified using MP – AES and that quantified using UV – Vis spectroscopy with a low root mean square error (RMSE = 9.245), MP – AES may have accuracy comparable to conventional methods. Linear regression of the exchangeable cations extracted using the Mehlich 3 method and quantified using MP – AES and those extracted using the 1 M NH4OAc method and quantified using ICP – AES revealed that the coefficients of determination of Ca, Mg, and K were 0.952, 0.878, and 0.826, respectively. The coefficient of determination for Na was small at 0.101. For the micronutrients, Mehlich 3 extraction with MP – AES quantification method showed a correlation with the conventional DTPA method; specifically, a strong correlation was observed for Cu and Zn. Although the correlation for Fe and Mn was also high, it was less accurate than that for the other elements. The method used in this study is considered effective for estimating field variability. To convert to conventional methods, variation in available elemental content between sites with different local soil properties should be considered.

Milk quality determined using chemical analysis and microwave plasma atomic emission spectrometry as a function of seasonality in two conventional Italian dairy farms

1Department of Veterinary Medicine and Animal Science (DIVAS), University of Milan, Italy 2Council for Agriculture Research and Economics-Research Centre for Animal Production and Aquaculture, Lodi, Italy 3Division of Rural Sciences and Food Systems, University of Malta, Msida, Malta

Milk quality determined using chemical analysis and microwave plasma atomic emission spectrometry as a function of seasonality in two conventional Italian dairy farms [pdf]

Milk quality determined using chemical analysis and microwave plasma atomic emission spectrometry as a function of seasonality in two conventional Italian dairy farms [pdf]

Determination of the Major By-Products of Citrus hystrix Peel and Their Characteristics in the Context of Utilization in the Industry

Kaffir lime (Citrus hystrix) is a popular citrus in Southeast Asia. Despite the growing interest in the peel of the fruit, the leaves are the most frequently used part of the fruit. The aim of the study was to determine the main by-products of the peel, such as pectins, minerals, essential oil, and bioactive compounds, and to evaluate the possibility of using them in various branches of industry. In the study of the essential oil obtained by hydrodistillation performed using the TGA chromatography technique (GC-MS), sabinene (31.93%), β-pinene (26%), and limonene (19%) were selected as the most abundant volatile compounds. Nine microelements (Fe, Zn, Cu, Mn, Co, Ni, Cr, Mo, and V), four macroelements (Mg, Ca, K, and Na), and seven ballast substances (Cd, Hg, Pb, Al, V, Sr, and Pt) were also determined using the microwave plasma-atomic emission spectrometry technique (MP-AES). In the case of microelements, iron 32.72 ± 0.39 mg/kg DW (dry weight) had the highest concentration. In the case of macroelements, the calcium content was 9416 ± 34 mg/kg DW. Optimization of the pectin extraction was also performed by selecting citric acid and obtaining a yield of 7.6-17.6% for acid extraction and 9.9-28.2% for ultrasound-assisted extraction (UAE), depending on the temperature used. The obtained pectins were characterized by the degree of methylation, galacturonic acid content, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, and DSC (differential scanning calorimetry) analysis. Among bioactive compounds, the contents of polyphenols (22.63 ± 2.12 mg GAE/g DW), flavonoids (2.72 ± 0.25 mg CE/g DW, vitamin C (2.43 ± 0.19 mg Asc), xantoproteins + carotenes (53.8 ± 4.24 ug), anthocyanins (24.8 ± 1.8 mg CGE/kg DW), and chlorophylls A and B (188.5 ± 8.1, 60.4 ± 3.23 µg/g DW) were evaluated. Antioxidant capacity using (cupric ion-reducing antioxidant capacity) CUPRAC and DPPH assays was also provided with the results of 76.98 ± 8.1, and 12.01 ± 1.02 µmol TE/g DW, respectively.

Major and heavy metals contents and health risk assessment of pumpkin peel, flesh and seed by microwave plasma-atomic emission spectroscopy

ABSTRACT. The aim of this study was to determine the levels of major (Na, Mg, K, Ca) and heavy (Cr, Mn, Fe, Ni, Cu, Zn, Cd) metals and health risk assessment of the peel, flesh and seed of pumpkins cultivated in Ethiopia, using microwave plasma-atomic emission spectrometry. Dried powdered samples (0.5 g) were wet digested with 69% HNO3 and 30% H2O2 in microwave digester. The percent recovery for the three parts of pumpkin samples were 90-110%. The mean concentration of metals in pumpkin peel, flesh, seed samples, respectively, were K (27806±9767, 29531±2452, 10667±1133), Ca (5267±2092, 3190±900, 2919±397), Mg (4716±469, 848±349, 4668±413), Fe (158±29, 111±46, 225±56), Na (167±116, 63.1±15, 171±123), Mn (28.9±1.4, 9.61±3.2, 33.4±4.9), Zn (24.2±4.4, 10.6±4.0, 67.5±12.3), Cu (8.14±1.1, 15.1±9.3, 10.8±0.9), Ni (3.79±2.4, 2.14±1.3, 3.44±2.8), Cr (0.28±0.1, 0.36±0.2, 0.69±0.1), Cd (0.24±0.1, 0.46±0.1, 1.39±0.2) mg/kg. The hazard index (HI) of pumpkin flesh and seed indicated ingestion of pumpkin is safe from non-carcinogenic risk. The total cancer risk (CR) due to consumption of pumpkin flesh and seed through Cr and Cd from the three sampling sites are in the range 1.1 x 10-4 -1.8 x 10-4, indicating a non-risk of exposure to cancer due to the consumption of pumpkin grown in the sampling areas.&#x0D;  &#x0D; KEY WORDS: Pumpkin, Mineral content, Health risk, Microwave plasma-atomic emission spectrometry&#x0D;  &#x0D; Bull. Chem. Soc. Ethiop. 2023, 37(3), 533-551.                                                        &#x0D; DOI: https://dx.doi.org/10.4314/bcse.v37i3.1

Use of a Portable X-Ray Fluorescence Analyzer for Rapid and Accurate Determination of Iron in Vitamins and Supplements

This study describes the development of an X-Ray Fluorescence (XRF) method to quantify iron in vitamins and supplements. Four different products and a NIST Standard Reference Material (SRM) were prepared by homogenizing 20 tablets in a mixer mill and diluting known masses of each sample into known masses of cellulose. Calibration standards were similarly prepared by diluting known masses of iron oxide into known masses of cellulose. Analyses were performed using a handheld XRF analyzer using one-minute analysis times. The method gave linear calibration curves with R2 values greater than 0.9995, and good accuracy as demonstrated by relative errors of 9% in the analysis of the NIST SRM. Experimentally determined concentrations of the samples were compared to the nominal concentration of the samples based on the mass of iron per tablet and the average tablet mass. XRF results gave relative differences of +4% and -4% for two iron supplements. XRF results gave a larger relative difference of -19% for the women’s vitamin product. Although the label on the men’s vitamin product stated it was iron-free, XRF and Microwave Plasma Atomic Emission Spectrometry (MP-AES) analyses showed it contained iron levels of 157 and 133 µg/g (ppm), respectively. This XRF method offers a simpler, faster, and less expensive alternative to conventional atomic spectrometry-based methods for this type of application.

Applicability of microwave induced plasma optical emission spectrometry for wear metal determination in lubricant oil using a multinebulizer

A new multinebulizer is combined/associated with an on-line standard dilution analysis for wear metal determination in lubricating oils by MP AES.

Elemental Analysis of Propolis Tinctures by Microwave Plasma – Atomic Emission Spectrometry (MP-AES)

Propolis tinctures are popular alternative medicines, but mandatory labeling requirements relating to the inorganic content or percentage of ethanol are absent. Knowing the elemental content is useful for quality assurance/quality control of the tinctures between batches, as well as the safety of the products for consumers. Microwave plasma – atomic emission spectrometry (MP-AES) is a relatively low-cost, robust, multielemental technique that can analyze ethanolic extracts of propolis following minimum sample preparation. However, there are no published papers using MP-AES for this application. The technique was evaluated for the determination of sixteen elements in lab-made preparations and in 23 products from markets in Mexico. The matrix effects of the ethanol content of the samples were also evaluated and were found to affect the detection limit of some elements. There was high variability in the elemental composition of the major (K, Fe, Mg, and Na) and minor (Al, Cd, Co, Cr, Cu, Mn, Ni, and Zn) elements among the samples. The median concentrations of cadmium, and lead in the propolis tinctures were below 0.28 µg·L−1 and 2.8 µg·L−1, respectively.

Determination of Alkali and Alkaline-Earth Metals in Water by Microwave Plasma Atomic Emission Spectrometry with the Addition of a Stabilizing Element

Determination of Alkali and Alkaline-Earth Metals in Water by Microwave Plasma Atomic Emission Spectrometry with the Addition of a Stabilizing Element

Method development and determination of potassium and phosphorus in oil palm organic fertilizers by microwave plasma atomic emission spectrometry (MP-AES)

Method development and determination of potassium and phosphorus in oil palm organic fertilizers by microwave plasma atomic emission spectrometry (MP-AES)

Heavy Metals Content in Laboratory Wastewater: A Case Study of Selected Units of Bayero University, Kano-Nigeria.

Heavy metals are well-known environmental pollutants due to their toxicity, persistence in the environment and bio-accumulative in nature. They contribute immensely in the environmental pollution and their sources include weathering of metal bearing rocks, mining, industrial and agricultural activities. Laboratory is a major point of research activities. This study is aimed at accessing the level of heavy metals in some laboratories wastewater in Bayero University, Kano. Four different laboratories where selected (Biochemistry, Chemistry, Microbiology and Central Laboratory complex) from Bayero University Old Campus. The wastewater samples were collected four times with one week interval and some heavy metals were determined using microwave plasma atomic emission spectrometry (MP-AES). The average mean concentrations of Cd, Cr, Co, Mn, Ni and Pb in each laboratory were compared with WHO standard in wastewater. The Results obtained from Biochemistry Laboratory for Cd, Cr, Co, Mn, Ni and Pb are 0.0067±0.0001, 0.0000±0.0000, 0.000±0.0000, 0.010±0.001, 0.027±0.0001 and 0.106±0.0001 mg/L respectively. Similarly Central laboratory with 0.07±0.001, 0.47±0.002, 0.00±0.00, 0.31±0.003, 0.10±0.002 and 0.20±0.001 mg/L. While Microbiology Laboratory with 0.00±0.00, 0.00±0.00, 0.00±0.00, 0.063±0.001, 0.027±0.001 and 0.093±0.0001 mg/L respectively. And Chemistry laboratory with 0.000±0.00, 0.607±0.0001, 0.053±0.002, 2.183±0.001, 0.127±0.0001 and 0.263±0.0002 respectively. Among all the laboratories, chemistry laboratory was found to have higher average mean concentrations of Mn, Ni and Pb and are above WHO Standard. However some heavy metals like Cr and Cd were found to be lower compared to WHO Standard. Therefore the wastewater studied contained some heavy metals which contribute to the environmental pollution and measures should be taken by the management concerned to ensure good laboratory waste management.

A New Type of Terpene‐Based D2‐Symmetric Macrocycles, Capable of Selectively Extracting Au, Pd and Pt from Complex Mixtures

AbstractC2‐symmetric terpene‐based bis(α‐amine oximes) prepared from monoterpene hydrocarbons (+)‐3‐carene, (−)‐α‐pinene and (+)‐limonene, when treated with methylene chloride under phase‐transfer conditions, undergo inter‐ and intramolecular cross‐linking at oxime groups to form D2‐symmetric macrocycles in relatively good preparative yields (35–64 %). The structure of the new compounds was solved by spectroscopic methods and proved by X‐ray crystallography. D2‐symmetric macrocycles are crystalline solids which are well soluble even in small amounts of low‐polar organic solvents. Using Microwave Plasma Atomic Emission Spectrometry the new compounds was found to be able to selectively extract some noble metals (PtIV, AuIII, PdII) from aqueous solutions with pH=1.2 containing complex mixtures of transition elements at with no noticeable extraction of d‐elements (CrVI, MnII, FeIII, CoII, NiII, CuII, ZnII) and other noble metals (RuIII, RhIII, IrIII).

High Sucrose Diet Induces Intestinal Zinc Dyshomeostasis and Permeability

ObjectivesZinc (Zn) is an essential micronutrient that is critical for many physiological processes including glucose metabolism, regulation of inflammation, regulation of intestinal barrier function, and insulin production and secretion. Further, Zn dysregulation is associated with increased risk of chronic inflammatory diseases such as type II diabetes, inflammatory bowel disease, and obesity. However, it remains unclear whether altered Zn status is a symptom or cause of disease onset. Common symptoms of these three inflammatory diseases include the onset of intestinal inflammation and increased intestinal permeability. The specific focus of this work is to investigate how dietary sources of chronic inflammation, such as high sucrose consumption impacts transporter mediated Zn homeostasis and subsequent Zn dependent physiology.MethodsTo study the interactions between high dietary sucrose and Zn homeostasis, we administered 30% sucrose water to mice for 8 weeks. Tissue metal contents were measured by microwave plasma atomic emission spectrometry. Zn transport was measured using radioisotope tracing of 65Zn. Intestine permeability was assessed by FITC-dextran (4 kDa) assay. Protein expression of Zn transporters, inflammatory markers, and tight junction proteins was measured by western blot.ResultsSucrose treatment resulted in systemic changes in steady-state Zn distribution, including a significant increase in plasma Zn and significant decreases in Zn in the liver, pancreas, and white adipose tissue. We observed changes in Zn transport protein expression in the intestine. In agreement with altered transporter expression, Zn transport studies revealed significant dysregulation of Zn transport in both the small intestine and colon. Further, sucrose treatment resulted in induction of both P-STAT3 and P-NF-κB, dysregulation of tight junction proteins ZO-1 and CLDN1, and increased intestine permeability.ConclusionsOur work suggests that chronic high sucrose consumption leads to changes in systemic Zn homeostasis. This links diet-induced changes in Zn homeostasis to the onset of precursors of chronic disease, intestinal inflammation and permeability.Funding SourcesThis work was supported by Cornell University Division of Nutritional Sciences funds to T. B. Aydemir.