Development and Application of an Atomic Absorption Spectrometry-Based Method to Quantify Magnesium in Leaves of Dioscorea polystachya

The Chinese yam (Dioscorea polystachya, DP) is known for the nutritional value of its tuber. Nevertheless, DP also has promising pharmacological properties. Compared with the tuber, the leaves of DP are still very little studied. However, it may be possible to draw conclusions about the plant quality based on the coloration of the leaves. Magnesium, as a component of chlorophyll, seems to play a role. Therefore, the aim of this research work was to develop an atomic absorption spectrometry-based method for the analysis of magnesium (285.2125 nm) in leaf extracts of DP following the graphite furnace sub-technique. The optimization of the pyrolysis and atomization temperatures resulted in 1500 °C and 1800 °C, respectively. The general presence of flavonoids in the extracts was detected and could explain the high pyrolysis temperature due to the potential complexation of magnesium. The elaborated method had linearity in a range of 1-10 µg L-1 (R2 = 0.9975). The limits of detection and quantification amounted to 0.23 µg L-1 and 2.00 µg L-1, respectively. The characteristic mass was 0.027 pg, and the recovery was 96.7-102.0%. Finally, the method was applied to extracts prepared from differently colored leaves of DP. Similar magnesium contents were obtained for extracts made of dried and fresh leaves. It is often assumed that the yellowing of the leaves is associated with reduced magnesium content. However, the results indicated that yellow leaves are not due to lower magnesium levels. This stimulates the future analysis of DP leaves considering other essential minerals such as molybdenum or manganese.

Metals in Cow Milk and Soy Beverages: Is There a Concern?

Nowadays, there is an increased consumption of plant-based protein beverages like soy beverages (SBs) as substitutes for cow milk (CM). Both accumulate toxic metals like lead (Pb), cadmium (Cd), and manganese (Mn), which, although essential, are neurotoxic at high levels. Metals can also perturb the normal development of children. This work aimed to evaluate these metal concentrations in CM and SB purchased on the Portuguese market. After validation of the method, linearity of calibration curves, work range, detection and quantification limits, and selectivity, metals were determined in 14 CM and 14 SB brands using atomic absorption spectrometry. The values were compared between CM and SB and with permissible limit values. Soy beverages had significantly (p < 0.05) higher concentrations of Cd (5.6 ± 4.2 µg/L) and Mn (117.4 ± 30.3) µg/L) than CM (2.15 ± 1.84 µg/L and 5.93 ± 1.21 µg/L, respectively); the Pb concentrations in CM (19.3 ± 12.1 µg/L) were not significantly (p > 0.05) higher than in SB (13.4 ± 9.6 µg/L). These values were similar to other studies and close to but under permissible limit values. Nevertheless, due to the toxicity and bioaccumulation of metals, the fact that these foods are routinely ingested by all ages, mainly children, and represent key ingredients in many processed foods, including baby foods, we suggest strict surveying of metal levels in CM and SBs.

Toxicological evaluation of a nonlethal riot control combinational formulation upon dermal application using animal models

Numerous adverse effects on human health have been reported in epidemiological studies of oleoresin capsicum (OC) and other riot control agents (RCAs). Importantly, the daunting risk of such RCAs can be neutralized by optimizing the desired concentration of such agents for mob dispersal. Hence, a nonlethal riot control combinational formulation (NCF) was prepared for dispersing rioters without imparting fatal outcomes. However, for desired utilization of NCF, it is essential to recognize its extent of potential toxicity. Therefore, the current investigation evaluated the dermal toxicity of NCF using experimental animals in compliance with the OECD guidelines. Additionally, few essential metal ions were analyzed and found non -significantly different in the test rats as compared to control rats. Moreover, abnormal dermal morphology and lesions ultrastructural tissue defects were not noticed as evinced by different studies like ultrasonography, histology, and scanning electron microscopy (SEM) respectively. Further, Doppler ultrasonography exhibited non-significantly different blood flow velocity in both groups, whereas miles test demonstrated a significantly increased Evans blue concentration in test rats compared to the control rats, which might be due to an initial increase in blood flow via an instant action of the NCF at the cutaneous sensory nerve endings. However, our results demonstrated NCF can produce initial skin irritating and sensitizing effects in guinea pigs and rabbits without the antecedence of acute toxicity (≤2000 mg/kg) in Wistar rats.

UV-C Seed Surface Sterilization and Fe, Zn, Mg, Cr Biofortification of Wheat Sprouts as an Effective Strategy of Bioelement Supplementation

Metalloenzymes play an important role in the regulation of many biological functions. An effective way to prevent deficiencies of essential minerals in human diets is the biofortification of plant materials. The process of enriching crop sprouts under hydroponic conditions is the easiest and cheapest to conduct and control. In this study, the sprouts of the wheat (Triticum aestivum L.) varieties Arkadia and Tonacja underwent biofortification with Fe, Zn, Mg, and Cr solutions in hydroponic media at four concentrations (0, 50, 100, and 200 µg g-1) over four and seven days. Moreover, this study is the first to combine sprout biofortification with UV-C (λ = 254 nm) radiation treatment for seed surface sterilization. The results showed that UV-C radiation was effective in suppressing seed germination contamination by microorganisms. The seed germination energy was slightly affected by UV-C radiation but remained at a high level (79-95%). The influence of this non-chemical sterilization process on seeds was tested in an innovative manner using a scanning electron microscope (SEM) and EXAKT thin-section cutting. The applied sterilization process reduced neither the growth and development of sprouts nor nutrient bioassimilation. In general, wheat sprouts easily accumulate Fe, Zn, Mg, and Cr during the applied growth period. A very strong correlation between the ion concentration in the media and microelement assimilation in the plant tissues (R2 > 0.9) was detected. The results of the quantitative ion assays performed with atomic absorption spectrometry (AAS) using the flame atomization method were correlated with the morphological evaluation of sprouts in order to determine the optimum concentration of individual elements in the hydroponic solution. The best conditions were indicated for 7-day cultivation in 100 µg g-1 of solutions with Fe (218% and 322% better nutrient accumulation in comparison to the control condition) and Zn (19 and 29 times richer in zinc concentration compared to the sprouts without supplementation). The maximum plant product biofortification with magnesium did not exceed 40% in intensity compared to the control sample. The best-developed sprouts were grown in the solution with 50 µg g-1 of Cr. In contrast, the concentration of 200 µg g-1 was clearly toxic to the wheat sprouts.

Metal Ions Release from Welded Co-Cr Dental Alloys

Cobalt-chromium alloys (Co-Cr) are widely used in dentistry due to their excellent mechanical properties and corrosion resistance. Since prosthetic materials must be permanently stable in the oral cavity, it is very important to determine the release of ions from alloys in the oral cavity. In dentistry today, metals and alloys are mainly joined by laser and tungsten inert gas (TIG) welding. Therefore, in this work, the release of metal ions from six different Co-Cr alloys joined by these two welding methods was quantified to determine the effects of the welding method on an ion release. Static immersion tests, atomic absorption spectrometry and statistical analysis were performed for this purpose. The results showed that laser-welded alloys release a lower amount of metal ions compared to TIG-welded alloys.

Relationships between the Content of Micro- and Macroelements in Animal Samples and Diseases of Different Etiologies

Many of the micro- and macro-elements (MMEs) required by the body are found in environmental objects in concentrations different from their original concentration that can lead to dangerous animal diseases ("microelementoses"). The aim was to study the features of MME (accumulating in wild and exotic animals) in connection with particular diseases. The work using 67 mammal species from four Russian zoological institutions was completed in 2022. Studies of 820 cleaned and defatted samples (hair, fur, etc.) after "wet-acid-ashing" on an electric stove and in a muffle furnace were performed using a Kvant-2A atomic absorption spectrometer. The content of zinc, copper, iron, cadmium, lead, and arsenic was assessed. The level of MME accumulation in the animal body contributes not only to the MME status and the development of various concomitant diseases, but the condition itself can occur by intake of a number of micronutrients and/or drugs. Particular correlations between the accumulation of Zn and skin, oncological diseases, Cu-musculoskeletal, cardiovascular diseases, Fe-oncological diseases, Pb-metabolic, nervous, oncological diseases, and Cd-cardiovascular diseases were established. Therefore, monitoring of the MME status of the organism must be carried out regularly (optimally once every 6 months).

Sol-Gel Graphene Oxide-Coated Fabric Disks as Sorbents for the Automatic Sequential-Injection Column Preconcentration for Toxic Metal Determination in Distilled Spirit Drinks

Sol-gel graphene oxide-coated polyester fabric platforms were synthesized and used for the on-line sequential injection fabric disk sorptive extraction (SI-FDSE) of toxic (i.e., Cd(II), Cu(II) and Pb(II)) metals in different distilled spirit drinks prior to their determination by electrothermal atomic absorption spectrometry (ETAAS). The main parameters that could potentially influence the extraction efficiency of the automatic on-line column preconcentration system were optimized and the SI-FDSE-ETAAS method was validated. Under optimum conditions, enhancement factors of 38, 120 and 85 were achieved for Cd(II), Cu(II) and Pb(II), respectively. Method precision (in terms of relative standard deviation) was lower than 2.9% for all analytes. The limits of detection for Cd(II), Cu(II) and Pb(II) were 1.9, 7.1 and 17.3 ng L^-1, respectively. As a proof of concept, the proposed protocol was employed for the monitoring of Cd(II), Cu(II), and Pb(II) in distilled spirit drinks of different types.

The Influence of Environmental Exposure to Heavy Metals on the Occurrence of Selected Elements in the Maxillary Bone

The elemental composition of the body's calcified tissues may reflect the environmental exposure of the population to heavy metals. The aim of the study was to assess whether the elemental composition of the maxillary bone from individuals belonging to a given population reflects the environmental exposure of this population to lead and cadmium. The research material consisted of cortical bone from the anterolateral walls of the maxilla collected from 126 patients during Caldwell-Luc maxillary sinus surgery on residents of two cities differing in terms of the lead and cadmium pollution of the natural environment. The content levels of lead, cadmium, iron, manganese, chromium, copper, and iron were determined by using atomic absorption spectrophotometry. The content levels of lead and cadmium in the samples of the maxillary bones of residents of Bielsko-Biala were 3.26 ± 2.42 µg/g and 0.74 ± 0.38 µg/g, respectively, whereas in the samples from the residents of Katowice, they were 7.66 ± 2.79 µg/g and 1.12 ± 0.08 µg/g, respectively. It was found that the lead and cadmium levels in the maxillary bone corresponded to the environmental exposure to these heavy metals in the place of residence, which was proven here via the example of the residents of two cities with different concentrations of these heavy metals in the air over long time periods. Additionally, higher content levels of essential metals such as manganese, chromium, copper, and iron are characteristic of the maxillary bone samples of residents of the area that is more polluted with heavy metals.

Assessment of the Quality of Herbal Teas from Šabac, Serbia in Terms of the Content of Heavy Metals

Chemical components of teas have received great interest because they are related to health. In this work, data on the determination of foreign matter, loss on drying/water content, total ash and ash insoluble in hydrochloric acid are presented. The content of seven heavy metals including Cu, Fe, Mn, Zn, Ni, Cd and Pb were determined by atomic absorption spectrometry in samples of several herbal teas: Matricariae flos, Thymi herba, Menthae piperitae folium, Betulae folium, Quercus cortex, Gentianae radix, Frangulae cortex, Althaeae radix, Uvae ursi folium and Glycyrrhizae radix collected from Šabac's market, Serbia. The sample preparation procedure involved dry digestion and dissolution of the ash in 6M HCl and then in 0.1 M HNO3. Herbal teas showed the concentration of heavy metals Cu, Fe, Mn, Zn and Ni in the range: 2.9 ± 0.1 - 22.2 ± 0.9 mg/kg, 118.5 ± 1.1 - 755.5 ± 2.5 mg/kg, 19.0 ± 5.8 - 561.0 ± 1.9 mg/kg, 6.5 ± 0.4 - 242.5 ± 1.4 mg/kg and 2.5 ± 0.1 - 10 ± 1.1 mg/kg, respectively. The level of copper in all samples was uniform. The highest content of Fe was in Thymi herba, while Mn and Zn were at maximum in Betulae folium. The levels of toxic heavy metals Cd and Pb were below the detection limit. The obtained values were compared with data available from literature. The herbal tea samples analyzed contained essential heavy metals (Cu, Fe, Mn, Zn) and probably essential in trace (Ni), and could obey the daily dietary requirements. Noncancer health risk assessment detected that the herbal teas of Betulae folium and Frangulae cortex can manifest some health risk to consumers.

Development of a Quantitative Determination Method for Aluminum Ions in Adsorbed Drugs Using Atomic Absorption Spectrometry with Electrothermal Atomization

A quantitative determination method for Al³⁺ in immunobiological drugs using atomic absorption spectroscopy with electrothermal atomization was developed. Conditions for the preparation of aluminum hydroxide gel were selected [NaOH (5 M), heating in a boiling-water bath for 5 min followed by neutralization with conc. HNO₃]. The method was validated. The analytical range of Al³⁺ was established in the interval 10 - 50 ig/L. The accuracy and in-laboratory precision were confirmed. The results allowed the proposed method to be considered an alternative for quantitative determination of Al³⁺ in immunobiological drugs.

Development of Chromium(III) Selective Potentiometric Sensors for Its Determination in Petroleum Water Samples Using Synthesized Nano Schiff Base Complex as an Ionophore

BACKGROUND

Many analytical techniques, such as X-ray fluorescence spectrometry, inductively coupled plasma atomic emission spectrometry (ICP-AES), and even traditional spectroscopic and fluorimetric methods, are used for the measurement of Cr(III) ions. These methods are sophisticated and very expensive. So, the chipset and the low cost ion selective electrodes were used.

OBJECTIVE

The quantification of Cr(III) ions in various samples of petroleum water using ion selective electrodes was suggested. Nano chromium modified carbon paste sensor (MCPE) and nano chromium modified screen printed sensor (MSPE) based on Schiff base Cr(III) complex are developed.

METHOD

The developed nano Cr(III) Schiff base chelate was characterized utilizing elemental, spectroscopic, and thermal analysis techniques. The proposed nano Cr(III) has a good properties for antibacterial and antifungal activity. The modified carbon paste and screen-printed sensors were fabricated for determination of Cr(III) ion.

RESULT

The proposed MCPE (sensor I) and MSPE (sensor II) obeys Nernstian equation upon incorporating nono Cr(III) ionophore in the paste at 25 °C with a trivalent cationic slope of 18.8 ± 0.2 and 20.0 ± 0.4 mV/decade. They have showed fast response time around 8 and 5 s, and they may be utilized for at least 98 and 240 days without significant changes in MCPE and MSPE potential, respectively. The sensors I and II showed good selectivity for Cr(III) ion toward a wide variety of metal ions or anions as confirmed by potentiometric selectivity coefficients values. The detection and quantification limits were defined alongside the other process validation parameters. The results have been compared well to those obtained by atomic absorption spectrometry (AAS) and the data of F- and t-test indicated no significant difference between the proposed and AAS methods.

CONCLUSION

These sensors have been utilized to determine Cr(III) ions in genuine spiked different petroleum well water samples with satisfactory percentage recoveries, low standard and relative standard deviation values using direct potentiometric and standard addition methods. The proposed method of producing nano Cr(III) complex as a sensor material possesses the distinct advantages of being simple, easily reproducible, appropriate for operation, and highly selective and sensitive.

HIGHLIGHTS

Modified carbon paste and screen-printed electrodes were fabricated based on nano Cr(III) complex as ionophore. The electrodes follow Nernstian behavior and they optimized according to IUPAC recommendation. They showed a high selectivity for Cr(III) ion over many bi or trivalent metal ions and anions. The results obtained compared well with those obtained using atomic absorption spectrometry (AAS). They successfully applied for determination of Cr(III) in petroleum water samples.

Heavy Metals, Proximate Analysis and Brine Shrimp Lethality of Vernonia amygdalina and Ocimum gratissimum Growing in Crude Oil-Rich Delta State, Nigeria

Vernonia amygdalina (VA) and Ocimum gratissimum (OG) are among the most frequently consumed vegetables in Kokori and Abraka communities of Delta State, Nigeria. However, the continuous crude oil exploration and spillages in Kokori may threaten their safety for use as food and medicine. Twelve samples of VA and OG obtained from crude oil-rich and crude oil-free communities were comparatively analysed for proximate composition, heavy metals, and cytotoxicity. Data obtained were subjected to various multivariate statistical techniques, including principal component analysis (PCA), biplot, and analysis of variance (ANOVA), to investigate the correlations between the vegetables from the different communities and the effect of crude oil exploration and spill on plant biomass. Results obtained indicate a significant difference (p < 0.05) in the proximate composition of VA and OG and higher heavy metal content for VA from the crude oil-spill Kokori. Two VA collections from Kokori were exceptionally toxic to cellular crustaceans.

Brewed Robusta Coffee Increases Nickel Ion Release from Dental Alloys: An In Vitro Study

Alloys in oral cavity always interact with dynamic oral environment, such as pH, temperature, salivary conditions, and dietary habits. Coffee can further decrease pH in the oral cavity. Thus, coffee may increase the release of metal ions that may lead to various health diseases. This study aimed to quantitively investigate the effect of brewed Robusta coffee on the nickel ion release and their morphological structures; Methods: 20 alloy specimens were divided into 4 groups and placed in solutions for 48 and 168 h: (1) distilled water, (2) artificial saliva, (3) Robusta coffee, and (4) mixture of artificial saliva and Robusta coffee. AAS, XRF, and SEM were used for examinations; Results: The release of Ni²⁺ was found in all groups and robust release were found in the coffee only and mixture of coffee + artificial saliva solution after 168 h. Likewise, SEM showed that internal oxidation was high after 168 h of immersion; Conclusions: The concentration of nickel increased in saliva of low pH due to brewed coffee. Though the release of these ions is still within the tolerable amount in human body, it should be realized that it usually lasts for months or years. Dentists should be cautious when using instructions for patients with a history of allergies especially for dietary with low acidity.

WELPSA: A natural catalyst of alkali and alkaline earth metals for the facile synthesis of tetrahydrobenzo[b]pyrans and pyrano[2,3-d]pyrimidinones as inhibitors of SARS-CoV-2

Since 2019, the infection of SARS‐CoV‐2 has been spreading worldwide and caused potentially lethal health problems. In view of this, the present study explores the most commodious and environmentally benign synthetic protocol for the synthesis of tetrahydrobenzo[b]pyran and pyrano[2,3‐d]pyrimidinones as SARS‐CoV‐2 inhibitors via three‐component cycloaddition of aromatic aldehyde, malononitrile, and dimedone/barbituric acid in water. Lemon peel from juice factory waste, namely, lemon (Citrus limon), sweet lemon (C. limetta), and Kaffir lime or Citron (C. hystrix), effectually utilized to obtain WELPSA, WESLPSA, and WEKLPSA, respectively, for the synthesis of title compounds. The catalyst was characterized by scanning electron microscope (SEM) and energy‐dispersive x‐ray spectroscopy (EDX). The concentration of sodium, potassium, calcium, and magnesium in the catalyst (WELPSA) was determined using atomic absorption spectrometry (AAS). The current approach manifests numerous notable advantages that include ease of preparation, handling and benignity of the catalyst, low cost, green reaction conditions, facile workup, excellent yields (93%–97%) with extreme purity, and recyclability of the catalyst. Compounds were docked on the crystal structure of SARS‐CoV‐2 (PDB: 6M3M). The consensus score obtained in the range 2.47–4.63 suggests that docking study was optimistic indicating the summary of all forces of interaction between ligands and the protein.

Assessment of Heavy Metals and Related Impacts on Antioxidants and Physiological Parameters in Oil Refinery Workers in Iraq

BACKGROUND

Some heavy metals can be harmful to human health in elevated doses such as zinc (Zn) and magnesium (Mg), while others such as lead (Pb), cadmium (Cd), mercury (Hg), and copper (Cu) have harmful consequences to health even in small doses. Heavy metals and additives are incorporated into crude oil to enhance performance.3,4,5 Crude oil is well known to contain heavy metals like Cu, Cd, Ni and Pb.3,6,7.

OBJECTIVE

The current study aimed to assess levels of heavy metals and the impact of these metals on antioxidant levels and physiological variables in the serum of oil refinery workers in Iraq.

METHODS

Heavy metals such as Pb, Cd, Hg, Zn, Cu and Mg were assessed in the serum of a sample of refinery workers (N=40) and a control group (N=20) using atomic absorption spectrometry (AAS). Additionally, levels of malondialdehyde (MDA), δ-aminolaevulinic acid dehydratase (ALAD) and total antioxidant capacity (TAC), and physiological variables such as blood urea, serum creatinine, glutamate-oxaloacetic transaminase (GOT), glutamate-pyruvic transaminase (GPT), and gamma-glutamyl transferase (GGT) were measured to assess impact of these heavy metals.

RESULTS

Mercury, Cd, and Pb were significantly elevated in the refinery worker group in comparison with the control group, while the levels of Zn, Cu, and Mg were significantly lower in the refinery worker group compared to the control group. There was a significant difference between the control group and the worker group for most of the antioxidants and functional variables. Total antioxidant capacity (TAC), δ-aminolevulinic acid dehydratase (ALAD), and malondialdehyde (MDA) were significantly lower in the worker group while blood urea, serum creatinine, glutamate pyruvate transaminase (GPT), and gamma-glutamyl transferase (GGT) showed a significant elevation in the workers' group. Glutamic oxaloacetic transaminase (GOT) showed no significant difference between the control group and the worker group.

CONCLUSIONS

Refinery workers are at increased risk of having higher serum levels of Pb, Cd, and Hg compared to controls which can lead to an increase in oxidative stress, decrease in TAC, and decrease in the essential trace elements Zn, Cu and Mg.

PARTICIPANT CONSENT

Obtained.

ETHICS APPROVAL

This study was approved by the ethics committee within the Nineveh Health Department, Mosul, Iraq.

COMPETING INTERESTS

The authors declare no competing financial interests.

[Determination of nickel and its compounds in a working environment]

BACKGROUND

Nickel and its compounds have been classified as carcinogenic in a regulation of the European Parliament called the CLP Regulation (Classification, Labeling and Packaging). This substance is found in industry in the production of steel and alloys, and in the production of protective coatings. In Poland, the value of the maximum allowable concentration (MAC) for nickel and its compounds, amounting to 0.25 mg/m³, will be reduced to 0.1 mg/m³. The aim of the study was to develop a selective method for the determination of nickel and its compounds in the air at workplaces, used to assess occupational exposure and compliant with the requirements for procedures of determining chemical factors in the work environment.

MATERIAL AND METHODS

The atomic absorption spectrometer SOLAAR M (ThermoElectron Corporation, USA) was used in the research.

RESULTS

The developed determination method consists in sampling nickel and its compounds contained in the air onto a membrane filter, followed by filter mineralization with concentrated acid and the determination of nickel with the use of atomic absorption spectrometry. A 1% lanthanum buffer was used to eliminate the Fe, Co, Cr and Cu interference. The method enables the determination of nickel in a wide concentration range of 0.25-10.00 μg/ml. The characteristic concentration for the determination of nickel was 0.07 μg/ml. The limit of quantification was 0.012 μg/ ml and the limit of detection was 0.004 μg/ml. The average value of the filter recovery coefficient is 1.00.

CONCLUSIONS

The developed method for the determination of nickel and its compounds allows for a selective determination of this substance in the air at workplaces in the concentration range of 0.014-0.56 mg/m³ and 0.007-0.28 mg/m³ for an air sample with a volume of 720 l. It allows for the determination of this substance from 1/10 to 2 MAC values for the current mandatory value of 0.25 mg/m³ as well as for the 2.5 times lower hygienic standard proposed to be introduced by 2025 as binding limit value in the EU. The method meets the requirements of PN-EN 482. Med Pr. 2021;72(3):267-81.

A Novel Glass Fiber Coated with Sol-Gel Poly-Diphenylsiloxane Sorbent for the On-Line Determination of Toxic Metals Using Flow Injection Column Preconcentration Platform Coupled with Flame Atomic Absorption Spectrometry

A novel simple and sensitive, time-based flow injection solid phase extraction system was developed for the automated determination of metals at low concentration. The potential of the proposed scheme, coupled with flame atomic absorption spectrometry (FAAS), was demonstrated for trace lead and chromium(VI) determination in environmental water samples. The method, which was based on a new sorptive extraction system, consisted of a microcolumn packed with glass fiber coated with sol-gel poly (diphenylsiloxane) (sol-gel PDPS), which is presented here for the first time. The analytical procedure involves the on-line chelate complex formation of target species with ammonium pyrrolidine dithiocarbamate (APDC), retention onto the hydrophobic sol-gel sorbent coated surface of glass fibers, and finally elution with methyl isobutyl ketone prior to atomization. All main chemical and hydrodynamic factors, which affect the complex formation, retention, and elution of the metal, were optimized thoroughly. Furthermore, the tolerance to potential interfering ions appearing in environmental samples was also explored. Enhancement factors of 215 and 70, detection limits (3 s) of 1.1 μg·L^-1 and 1.2 μg·L^-1, and relative standard deviations (RSD) of 3.0% (at 20.0 μg·L^-1) and 3.2% (at 20.0 μg·L^-1) were obtained for lead and chromium(VI), respec tively, for 120 s preconcentration time. The trueness of the developed method was estimated by analyzing certified reference materials and spiked environmental water samples.

Mercury accumulation in plants from contaminated arable lands in Eastern Slovakia

INTRODUCTION AND OBJECTIVE

Contamination of soil by mercury poses several risks to human health through consumption of fruits and vegetables. In Slovakia, a high concentration of mercury is found in the soil of the Central Spiš region. The objective of the study is to measure the mercury concentrations in the parts of selected plant species and trees growing within 100 meters of a former ore processing facility.

MATERIAL AND METHODS

A total of 24 samples of plants, 20 samples of parts of needle-leaved trees and 9 samples of parts of broad-leaved trees were collected from soils with a high concentration of mercury. The concentration was measured by atomic absorption spectrometry in different parts of the plants: leaves - 18 species, roots - 15 species, stems - 11 species, flowers - 7 species), and different parts of trees (crust - 8 species, branches - 8 species, needles - 5 species, cones - 5 species, leaves - 3 species).

RESULTS

The concentrations of mercury in the soils taken at a depth of 0.25 m exceeded the maximum allowed levels more than 50-times. Potatoes, parsley and carrots from these soils exceeded the maximum allowed mercury levels 6-times, 5-times and twice, respectively. The average concentrations of mercury in the roots of 2-year onions exceeded the limit more than 50-times. The flowers of cornflower contain 18.20 mg*kg ^-1 , leaves of dandelion 10.61 mg*kg ^-1 and roots of plantain 6.80 mg*kg ^-1 of mercury. Regarding trees, the highest concentrations were found in the branches of juniper and leaves of aspen - more than 1 mg*kg ^-1.

CONCLUSIONS

The systematic monitoring of mercury is still very important, since it was found that the end of ore processing does not solve the issue of contamination in the Central Spiš region. Therefore, the consumption of fruits and vegetables from the areas of former ore processing facilities is not recommended.

Preparation of a Reference Material for the Determination of Hexavalent Chromium in Tap Water

We developed a reference material (RM) for the determination of hexavalent chromium (Cr(VI)) in tap water. The tap water RM was prepared by adding a Cr(VI) standard solution to the raw material without acidification, i.e., under the original pH conditions of 7.6, because the decrease in the concentration of Cr(VI) was observed when the tap water had been adjusted to pH 1 with HNO₃. The prepared tap-water RM (2 L) was packed in 10 fluororesin (PFA) bottles with an inside plug (200 mL each). Each PFA bottle (Cr(VI)-containing tap water) was sealed in a reclosable poly bag and then stored at 5°C in a refrigerator. The tap water RM had a Cr(VI) concentration of 51 μg L^-1. The concentration of Cr(VI) was determined by diphenylcarbazide absorptiometry using a 100-mm quartz cell. The detection limit of Cr(VI) in the sample solution corresponding to three-times the standard deviation (n = 5) of blank values was 0.51 μg L^-1. The homogeneity of Cr(VI) in the tap water RM was evaluated by an analysis of the variance after the Cochran test. There was no significant difference between the within-bottle and between-bottle variances of the analytical results, indicating that the tap water RM was sufficiently homogeneous. The stability of Cr(VI) in the tap water RM was investigated by monitoring the Cr(VI) concentration over a period of 6 months. The slope of the regression line of the Cr(VI) concentration versus the storage time did not significantly differ from zero, indicating that the tap water RM was stable for 6 months. The concentrations (50 - 51 μg L^-1) of Cr(VI) in the tap water RM were in good agreement with the total chromium concentrations (50 - 51 μg L^-1) obtained by atomic absorption spectrometry.

Influence of Feeding Substrates on the Presence of Toxic Metals (Cd, Pb, Ni, As, Hg) in Larvae of Tenebrio molitor: Risk Assessment for Human Consumption

Larvae of Tenebrio molitor L. (Coleoptera: Tenebrionidae) are particularly suitable as novel food for the human consumption; nevertheless, there are some potential safety risks linked with insect consumption. In this study we investigated the presence of Cd, Pb, Ni, As, Hg in new feeding substrates coming from solid residues generated by olive fruits processing, called olive-pomace, and their influence on the metal content in larvae of T. molitor. Morover, bioaccumulation factor and the mercury-selenium balance were evaluated. Analyses were carried out via graphite furnace atomic absorption spectrophotometry for Cd, Pb, Ni, As and Se, and via Direct Mercury Analyzer for Hg. All metal concentrations found in feeding substrates were below the legal limit of undesirable substances in animal feed (2002/32/EC). Concentrations in larvae were in the range (mg kg^-1 wet weight): Cd 0.008-0.016, Pb 0.063-0.079, Ni 0.03-0.63, As 0.021-0.023, Hg 0.12 × 10^-3-0.49 × 10^-3, and Se 0.057-0.085. Statistically significant correlation between metal content in feeding substrates and in larvae was evidenced only for Hg, which bioaccumulates. Se protects from mercury toxicity, with a Selenium Health Benefit Value (HVB_Se) of > 0. Overall, our results indicate that the risk of exposure to metals from consumption of mealworm larvae is relatively low and in compliance with European Union regulations.

Iron excretion in urine in patients with acute kidney injury after cardiac surgery

BACKGROUND

Hemolysis during cardiopulmonary bypass may lead to acute kidney injury caused by an excessive amount of iron. The clinical usefulness of the measurement of total iron concentration in the urine with the use of the atomic absorption spectrometry method for early identification of patients with postoperative acute kidney injury is not well-established.

OBJECTIVES

An observational, prospective study was conducted on a group of 88 pre-selected adult patients undergoing a planned coronary artery bypass grafting (CABG) procedure.

MATERIAL AND METHODS

The amount and concentrations of total iron, creatinine and neutrophil gelatinaseassociated lipocalin (NGAL) were evaluated in urine samples. A comparative analysis of the evaluated biochemical parameters was performed in regard to the occurrence of acute kidney injury 48 h postoperatively.

RESULTS

Patients in the acute kidney injury group presented more advanced age (p = 0.01), preoperative myocardial infarction (p = 0.02), diuresis reduction (p = 0.04), and lower total iron levels in the 48-hour urine sample (p = 0.01). There was no difference when considering iron concentration in single urine samples in the study group.

CONCLUSIONS

The sole result of total iron concentration in single urine samples is unreliable for the diagnosis of acute kidney injury after cardiac surgery. Decreased excretion of iron in the urine seems to be an important additional element in the multifactorial pathogenesis of acute postoperative kidney failure.

Fish and fish products as risk factors of mercury exposure

INTRODUCTION

Mercury is ubiquitous in the biosphere, occurring in the air, water, land, and soil, as well as in living organisms. Excessive exposure to mercury is associated with a wide range of adverse health effects including damage to the central nervous system and the kidneys. Mercury exists in many different forms in the environment which produce various patterns of toxicity. Protection of the food chain from contamination by mercury is an important task in the protection of health of the human population.

OBJECTIVE

The aim of the study was to monitor the concentrations of mercury in fish and fish products from food retail in Eastern Slovakia, and from the Ružín water reservoir, Košice district.

MATERIAL AND METHODS

A total of 384 samples of fish and fish products were collected for the study. Atomic absorption spectrometry standard solutions for mercury were used at a wavelength of 254 nm.

RESULTS

The majority of countries and global organizations now enforce a maximum concentration of mercury in fish of approximately 0.5 mg.kg^-1. All of the 184 samples (50.52 % of the total fish samples studied) were above the maximum level set by the European Commission Regulation for mercury in fish.

CONCLUSIONS

The systematic analytical control of contaminants in food is important. Mercury is concentrated in seafood, products of prey and marine fish, fish from rivers and lakes in the areas contaminated by mercury. According to the findings of this study with analyzer AMA 254, the consumption is not recommended of fish, especially seafood (meat of shark, swordfish and king mackerel), for selected groups of the population: children, women of childbearing age, pregnant women and nursing mothers.

Impact of low level radiation on concentrations of some trace elements in radiation workers

INTRODUCTION

Small variations in trace element levels may cause important physiological changes in the human body. This study aims to evaluate five important trace elements in radiation workers.

METHOD

In this study, 44 radiation workers and an equal number of non-radiation workers were selected as the case and control group, respectively. The concentrations of iron, magnesium, zinc, copper, and selenium in the serum of the participants were measured using an Atomic Absorption Spectrometry (AAS).

RESULTS

The mean concentrations of iron, magnesium, zinc, copper, and selenium for the case group were 107.3 µg/dl, 2.3 mg/dl, 80.9 µg/dl, 112.6 µg/dl and 216.7 ng/ml, respectively. The results for the control group were 121.9 µg/dl, 2.3 mg/dl, 82.3 µg/dl, 112.8 µg/dl and 225.2 ng/ml, respectively.

CONCLUSIONS

The mean concentration of iron in the case group was significantly lower than the control group (p-value = 0.012), while the concentrations of other elements in both of the groups were not significantly different. In the case group, except magnesium (p-value = 0.021), no significant relationship was found between age and the elemental concentrations. According to Spearman's test, there was a meaningful statistical correlation between the sex and concentration of iron, Mg, Zn, and Se. Also, the correlation between the concentration of magnesium and the weights of radiation workers was significant (p-value =0.044).

Lead, Cadmium and Nickel Contents of Some Medicinal Agents

Thirty nine brands of pharmaceutical dosage forms (28 tablets, 4 syrups, 6 suspensions and one chewing gum) that are available in United Arab Emirates pharmaceutical markets were investigated for the presence of three heavy metals; lead, cadmium and nickel. Amongst the samples, 13 products were manufactured locally in United Arab Emirates and 26 products were imported from around the world. The samples were prepared by acid digestion procedure and the resultant solutions were analyzed for heavy metals by using a validated graphite furnace atomic absorption spectrometric method. Calibration curves were achieved using different concentration of lead, nickel and cadmium ranged from 0.001 to 0.05 μg/ml. The mean recoveries of metals from the samples were 86.4 to 97%. The %relative standard deviation for the intraassay and interday precision for the metals were <5%. Amongst the 39 samples of pharmaceutical dosage form all exhibited a positive response for lead, cadmium and nickel except three products whose Ni levels were below quantification level. The products contained variable amounts of heavy metals as of 0.0017 to 11.88 μg lead; 0.0011 to 0.5559 μg cadmium and 0.0011 to 2.6428 μg nickel, respectively. Based on maximum recommended daily dose (g) of these products, maximum daily ingested mass of lead was 0.0034 to 11.88 μg/d, 0.0013 to 0.56 μg/d for cadmium and 0.0011 to 2.64 μg/d for nickel, respectively. The results were compared with those of oral permitted daily exposure levels of United State Pharmacopeial National Formulary 2013. All the products were safe to consume and contained lower level of lead, cadmium and nickel than Oral Permitted Daily Exposure levels, except three products which showed higher level of lead than oral permitted daily exposure levels. Hence the raw materials used in manufacturing of these medicinal agents might be responsible for the presence of higher level of lead.

[Determination of Al, Be, Cd, Co, Cr, Mn, Ni, Pb, Se and Tl in whole blood by atomic absorption spectrometry without preliminary sample digestion]

Methods of whole blood trace element determination by Graphite furnace atomic absorption spectrometry (in the variant of Zeeman's modulation polarization spectrometry) have been proposed. They do not require preliminary sample digestion. Furnace programs, modifiers and blood dilution factors were optimized. Seronorm™ human whole blood reference materials were used for validation. Dynamic ranges (for undiluted blood samples) were: Al 8 ¸ 210 мg/L; Be 0.3 ¸ 50 мg/L; Cd 0.2 ¸ 75 мg/L; Сo 5 ¸ 350 мg/L; Cr 10 ¸ 100 мg/L; Mn 6 ¸ 250 мg/L; Ni 10 ¸ 350 мg/L; Pb 3 ¸ 240 мg/L; Se 10 ¸ 500 мg/L; Tl 2 ¸ 600 мg/L. Precision (RSD) for the middle of dynamic range ranged from 5% for Mn to 11 for Se.

Honeybees and honey as monitors for heavy metal contamination near thermal power plants in Mugla, Turkey

In the present work, 6 honeydew samples of known geographical and botanical origins and 11 honeybee samples were analyzed to detect possible contamination by the thermoelectric power plants in Mugla, Turkey. The contents of trace elements were determined by atomic absorption spectrometry after application of microwave digestion. The samples from the thermal power plants, which were 10-22 km away from the hives, that did not cause pollution in honeydew honeys were also analyzed. The levels of copper, cadmium (Cd), lead (Pb), zinc, manganese, iron, chromium, nickel, and aluminum were similar to the values found in other recent studies in literature. However, it was found that the contamination levels of the toxic elements such as Pb and Cd in honeybee samples measured relatively higher than that of honey samples. The study concludes that honeybees may be better bioindicators of heavy metal pollution than honey.

The contribution of heavy metals in cigarette smoke condensate to malignant transformation of breast epithelial cells and in vivo initiation of neoplasia through induction of a PI3K-AKT-NFκB cascade

Cigarette smoking is a crucial factor in the development and progression of multiple cancers including breast. Here, we report that repeated exposure to a fixed, low dose of cigarette smoke condensate (CSC) prepared from Indian cigarettes is capable of transforming normal breast epithelial cells, MCF-10A, and delineate the biochemical basis for cellular transformation. CSC transformed cells (MCF-10A-Tr) were capable of anchorage-independent growth, and their anchorage dependent growth and colony forming ability were higher compared to the non-transformed MCF-10A cells. Increased expression of biomarkers representative of oncogenic transformation (NRP-1, Nectin-4), and anti-apoptotic markers (PI3K, AKT, NFκB) were also noted in the MCF-10A-Tr cells. Short tandem repeat (STR) profiling of MCF-10A and MCF-10A-Tr cells revealed that transformed cells acquired allelic variation during transformation, and had become genetically distinct. MCF-10A-Tr cells formed solid tumors when implanted into the mammary fat pads of Balb/c mice. Data revealed that CSC contained approximately 1.011μg Cd per cigarette equivalent, and Cd (0.0003μg Cd/1×10(7) cells) was also detected in the lysates from MCF-10A cells treated with 25μg/mL CSC. In similar manner to CSC, CdCl2 treatment in MCF-10A cells caused anchorage independent colony growth, higher expression of oncogenic proteins and increased PI3K-AKT-NFκB protein expression. An increase in the expression of PI3K-AKT-NFκB was also noted in the mice xenografts. Interestingly, it was noted that CSC and CdCl2 treatment in MCF-10A cells increased ROS. Collectively, results suggest that heavy metals present in cigarettes of Indian origin may substantially contribute to tumorigenesis by inducing intercellular ROS accumulation and increased expression of PI3K, AKT and NFκB proteins.

Trace elements (copper, zinc, selenium and molybdenum) as markers in oral sub mucous fibrosis and oral squamous cell carcinoma

Oral cancer is a major cause of cancer morbidity and mortality worldwide and is prevalent in most areas where tobacco related practices are observed. Essential elements play a role in many biochemical reactions as a micro-source and there is growing evidence that their concentrations are altered on the onset and progress of malignant disease. In this study the levels of copper (Cu), zinc (Zn), selenium (Se) and molybdenum (Mo) in serum of patients with oral sub mucous fibrosis (OSMF) (n = 30) and oral squamous cell carcinoma (OSCC) (n = 30); were determined and the alterations of these critical parameters were analyzed in comparison with controls (n = 30) to identify predictors amongst these parameters for disease occurrence and progression. The serum Cu and Zn were established using Flame Atomic Absorption Spectrometry. Serum estimation of Se and Mo was done by graphite furnace atomic absorption spectrometry (GFAAS). Data analysis revealed a marked, progressive and significant increase in Cu levels in precancer (OSMF) and cancer (OSCC) groups as compared to the normal group. The level of Zn in serum was slightly elevated in OSMF and OSCC though not statistically significant. Cu/Zn ratio was slightly but not significantly elevated. Serum levels of Se and Mo were significantly decreased in the precancer and cancer groups as compared to the normals.

Sample preparation for arsenic speciation in terrestrial plants--a review

Arsenic is an element widely present in nature. Additionally, it may be found as different species in several matrices and therefore it is one of the target elements in chemical speciation. Although the number of studies in terrestrial plants is low, compared to matrices such as fish or urine, this number is raising due to the fact that this type of matrix are closely related to the human food chain. In speciation analysis, sample preparation is a critical step and several extraction procedures present drawbacks. In this review, papers dealing with extraction procedures, analytical methods, and studies of species conservation in plants cultivated in terrestrial environment are critically discussed. Analytical procedures based on extractions using water or diluted acid solutions associated with HPLC-ICP-MS are good alternatives, owing to their versatility and sensitivity, even though less expensive strategies are shown as feasible choices.

A possible predictive marker of progression for hepatocellular carcinoma

The correlation between decreased levels of selenium and increased DNA damage and oxidative stress shows the significance of this trace element. A number of studies have provided evidence for lower serum, plasma and tissue levels of selenium in patients with various diseases and types of cancer. In this study, liver selenium concentrations were measured in tissue samples of patients with hepatocellular carcinoma (HCC) by atomic absorption spectrometry. The results showed that the selenium concentrations decreased when the malignant grade increased. Furthermore, a significant correlation was found between selenium levels and human selenium binding protein-1 (SELENBP1) down-regulation in the liver. Therefore, we suggest that the evaluation of selenium and SELENBP1 concentrations can be used for improving the prognosis of HCC.

Novel atomic absorption spectrometric and rapid spectrophotometric methods for the quantitation of paracetamol in saliva: application to pharmacokinetic studies

A novel atomic absorption spectrometric method and two highly sensitive spectrophotometric methods were developed for the determination of paracetamol. These techniques based on the oxidation of paracetamol by iron (III) (method I); oxidation of p-aminophenol after the hydrolysis of paracetamol (method II). Iron (II) then reacts with potassium ferricyanide to form Prussian blue color with a maximum absorbance at 700 nm. The atomic absorption method was accomplished by extracting the excess iron (III) in method II and aspirates the aqueous layer into air-acetylene flame to measure the absorbance of iron (II) at 302.1 nm. The reactions have been spectrometrically evaluated to attain optimum experimental conditions. Linear responses were exhibited over the ranges 1.0-10, 0.2-2.0 and 0.1-1.0 mug/ml for method I, method II and atomic absorption spectrometric method, respectively. A high sensitivity is recorded for the proposed methods I and II and atomic absorption spectrometric method value indicate: 0.05, 0.022 and 0.012 mug/ml, respectively. The limit of quantitation of paracetamol by method II and atomic absorption spectrometric method were 0.20 and 0.10 mug/ml. Method II and the atomic absorption spectrometric method were applied to demonstrate a pharmacokinetic study by means of salivary samples in normal volunteers who received 1.0 g paracetamol. Intra and inter-day precision did not exceed 6.9%.