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Catalytic hydrogenolysis of polypropylene and polyethylene mixtures: Effect of temperature on liquid alkane components
Date: 2024Authors: Ma, W;Wang, C;Chen, Z;Yan, S;Cao, S;Wang, X;Chen, Y;Yang, H;Chen, H;
References: Journal of the Energy Institute ~ 101615
Keywords/Products: Agilent;ICP;ICP-OES;Meinhard;
This study explored the interactions between different polyolefins using a commercial Ru/C catalyst-mediated hydrogenolysis of polypropylene (PP), low-density polyethylene (LDPE), and their mixtures. The effects of the mass ratio of polyolefins to the catalyst, temperature, pressure and time on the yield of products and the internal components of liquid alkane products were studied, and the optimum conditions for solo plastic hydrogenolysis were determined. The highest liquid alkane yields of PP (46.70%) and LDPE (70.70%) were obtained at 250 and 210?°C, respectively. Further, the interactions between PP and LDPE during co-hydrogenolysis were observed. The temperature had a significant influence on the gaseous and liquid products, and we proposed a two-step hydrogenolysis reaction process for a mixture of polyethylene with polypropylene conducted at various temperatures. Co-hydrogenolysis provides a high-value utilization path for polyolefins that are difficult to separate during recovery.
Metal Content, Fatty Acid and Vitamins in Commercially Available Canned Fish on the Bulgarian Market: Benefit-Risk Ratio Intake
Date: 2024Authors: Peycheva, K;Panayotova, V;Hristova, T;Merdzhanova, A;Dobreva, D;Stoycheva, T;Stancheva, R;Licata, P;Fazio, F;
References: Foods (Basel, Switzerland) 13 ~
Keywords/Products: Concentric;Meinhard;
Today, the distribution and consumption of canned products have become widespread due to the convenience of using processed fish products. This study aims to evaluate elements of toxicological concern and essential elements (Cd, Al, Cu, Cr, Mn, Fe, Pb, Ni, and Zn), the fatty acid composition, and the fat-soluble vitamin and antioxidant pigment contents of various canned fish products purchased on the Bulgarian market. The estimated weekly intake and human health benefit-risk ratio based on metal elements and n-3 LC-PUFA contents in canned fish products were assessed. The contents of the analyzed elements in the canned samples were found to be below the limits set by various health organizations. Al was detected in only one sample. The profile of fatty acids showed that the canned fish had high PUFA/SFA ratios, EPA + DHA contents and low SFA, AI and TI values. The analyzed canned fish contained significant contents of fat-soluble vitamins. The Atlantic bonito in a jar sample was characterized by a high percentage of vitamin A (26.7% RDI) and vitamin D3 (142% RDI) per 100 g portion. The calculated EWI value shows that the consumption of canned fish products did not present any risk. The benefit-risk ratio indicates that the canned fish species are safe for human consumption, except for one sample regarding Cr.
Relationships between Trace Elements and Cognitive Behaviors in Sprague Dawley and Wistar Albino Rats
Date: 2024Authors: Yavuz, M;Dayanc, ED;Merve Antmen, F;
References: Frontiers in Pharmacology ~ ~
Keywords/Products: Concentric;ICP;ICP-MS;Meinhard;
Introduction: This study investigates the effects of social isolation on mental health and cognitive functions in Sprague Dawley (SD) and Wistar Albino (WIS) rat strains, prompted by the heightened awareness of such impacts amid the COVID-19 pandemic. This study aims to explore the impact of social isolation on memory, learning, and behavioral changes in middle-aged SD and WIS rat strains and to investigate cortical trace element levels, seeking potential correlations between these levels and the observed behavioral responses to social isolation. Methods: Four groups of 14-month-old male rats were established: control and isolated SDs and WIS rats (CONT-SD, ISO-SD, CONT-WIS, ISO-WIS). Morris Water Maze and Porsolt Forced Swimming tests were conducted for behavioral assessment. Following behavioral tests, rats were sacrificed under general anesthesia, and cortices were isolated for analysis of macro and trace element levels (ICP/MS). Results: In behavioral tests, CONT-SD rats exhibited superior performance in the Morris Water Maze test compared to CONT-WIS rats, but displayed increased depressive behaviors following social isolation, as evident in the Porsolt Forced Swimming test (p < 0.05). ISO-SD rats showed elevated levels of Co and Cu, along with reduced levels of Cs and As, compared to ISO-WIS rats. Moreover, isolation resulted in decreased Cu and Mo levels but increased Rb levels in WIS rats. Comparison of trace element levels in naïve groups from different strains revealed lower Zn levels in the WIS group compared to SD rats. Discussion: The findings suggest that the SD strain learns faster, but is more susceptible to depression after isolation compared to the WIS strain. Increased Co and Cu levels in ISO-SD align with previous findings, indicating potential trace element involvement in stress responses. Understanding these mechanisms could pave the way for preventive treatment strategies or therapeutic targets against the consequences of stressors, contributing to research and measures promoting a balanced diet to mitigate neurobehavioral abnormalities associated with social isolation in the future.
Lithium Content and Its Nutritional Beneficence, Dietary Intake, and Impact on Human Health in Edibles from the Romanian Market
Date: 2024Authors: Iordache, AM;Voica, C;Roba, C;Nechita, C;
References: Foods (Basel, Switzerland) 13 ~
Keywords/Products: ICP;ICP-MS;Meinhard;
Lithium (Li) is present in human nutrition based on food intake, and several studies recommend it for treating mood disorders, even if the biological proprieties and biochemical mechanisms represent the basis for its use as an essential element. The Li content was evaluated using the inductively coupled plasma mass spectrometry technique (ICP-MS) in 1071 food and beverage samples from the Romanian market. The results show that Li had a decreasing mean concentration in the food samples as follows: vegetables leafy > bulbous > fructose > leguminous > egg whites > root vegetables > milk products > egg yolks > meats. Approximately a quarter of all data from each dataset category was extreme values (range between the third quartile and maximum value), with only 10% below the detection limit. Mean Li concentration indicated higher values in red wine, white wines, beers, and fruit juice and lower in ciders and bottled waters. A particular interest was addressed to plants for teas and coffee seeds, which showed narrow amounts of Li. For both food and beverages, two similar matrices, including egg whites and yolks and white and red wines, were found to have significant differences, which explains the high variability of Li uptake in various matrices. For 99.65% of the analyzed samples, the estimated daily intake of Li was below the provisional subchronic and chronic reference dose (2 µg/kgbw/day) for adverse effects in several organs and systems. Even so, a risk occurs in consuming bulbous vegetables (Li > 13.47 mg/kg) and fructose solano vegetables (Li > 11.33 mg/kg). The present study's findings indicate that ingesting most of the analyzed beverages and food samples could be considered safe, even if future studies regarding Li content, nutritional aspects, and human cohort diseases must be conducted.
Analysis of microplastic particles by using single particle inductively coupled plasma mass spectrometry
Date: 2024Authors: Sakanupongkul, A;Sirisinha, K;Saenmuangchin, R;Siripinyanond, A;
References: Microchemical Journal 199 110016
Keywords/Products: Concentric;ICP;ICP-MS;Meinhard;sample introduction;Type C;
A method based on single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) with the use of regular sample introduction system was developed for the study of microplastics released from consumer products. With the standard type nebulizer used in SP-ICP-MS, the effect of sample introduction rate was evaluated and the flow rate of 0.18 mL min?1 was selected for further use. Under this condition, the transport efficiency was determined by using a commercially available uniform size of 50 nm AuNPs, and the calibration graph was constructed by using sucrose as dissolved forms of carbon. With this calibration approach, size analysis of polystyrene particles in the range of 1 - 6 µm was performed with the size detection limit of approx. 400 nm. The SP-ICP-MS was then applied to determine the particle size of laboratory synthesized polystyrene latex. The sizes obtained were found to positively deviate from the reference sizes reported by scanning electron microscopy (SEM), suggesting the potential problem from matrix interferences. Therefore, particle washing method by using deionized water was proposed to purify the polystyrene particles from their suspending medium. After particle washing, the sizes obtained from SP-ICP-MS with correction factor agreed well with the reference sizes. Therefore, the SP-ICP-MS method was applied to investigate the microplastics released from teabags and disposable face masks with the results compared with those from dynamic light scattering (DLS) and SEM.
Toxic Effects of Different Coating-Related Functionalized Nanoparticles on Aquatic Organisms
Date: 2024Authors: Hernández-Moreno, D;Fernández-Díaz, M;Rucandio, I;Navas, JM;Fernández-Cruz, ML;
References: Toxics 12 ~
Keywords/Products: iCAP;iCAP-Q;ICP;ICP-MS;Meinhard;sample introduction;Thermo;
The peculiar physico-chemical characteristics of nanomaterials (NMs) and the use of different coatings to improve their expected properties result in a huge amount of nanoforms, which vary in chemical composition, size, shape and surface characteristics. This makes it almost impossible to test all the nanoforms available, and efforts have been made to establish grouping or read-across strategies. The aim of this work was to find a behavior pattern of effect among nanoforms of different metallic core nanoparticles (NPs) (TiO2, CeO2 and Ag NP) with the same coatings (sodium citrate, poly (ethylene glycol), dodecylphosphonic acid or oleylamine). Daphnia magna, rainbow trout and two fish cell lines (PLHC-1 and RTH-149) were exposed to a range of concentrations (up to 100 mg/L) of the uncoated or coated NPs. Ag NPs were the most toxic, followed by CeO2 NPs and finally by TiO2 NPs. The results show that a clear pattern of toxicity in the studied species could not be established related to the coatings. However, it was possible to confirm different inter-species sensitivities. RTH-149 was the most sensitive cell line, and Daphnia magna was more sensitive than fish. Moreover, some differences in coating-core interactions were found between the metal oxide and the metal NPs in Daphnia magna.
CHART: a novel system for detector evaluation against toxic chemical aerosols
Date: 2024Authors: Durán Jiménez, D;Venema, T;de Bruin-Hoegée, M;Alkema, DPW;Busker, RW;van Wuijckhuijse, AL;
References: Scientific reports 14 1050
Keywords/Products: Aerosol;Meinhard;
Concern over the possibility of deliberate dispersion of chemical warfare agents and highly toxic pharmaceutical based agents as persistent aerosols has raised the need for experimental assessment of current and future defensive capabilities of armed forces and law enforcement agencies. Therefor we herewith present the design, realization and validation of the Chemical Hot Aerosol Research Tool (CHART) as a validated and safe experimental set-up for performance evaluation of chemical detection and identification equipment against chemical warfare agents and other highly toxic compounds. In the CHART liquid and solid compounds in solution or suspension are being dispersed as aerosols in a nebulization chamber. A broad dynamic particle size range can be generated, including particles known to be able to reach the lower respiratory tract. The aerosol generated is presented to the detection system-under-test while being monitored and characterized in real-time, using an optical particle counter and a time-of-flight aerosol analyzer, respectively. Additionally, the chemical composition of the aerosol is ex situ measured by analytical chemical methods. Evidently, in the design of the CHART significant emphasis was placed on laboratory safety and containment of toxic chemicals. The CHART presented in this paper has proven to be an indispensable experimental tool to study detectors and fieldable identification equipment against toxic chemical aerosols.
Probabilistic health risk assessment of heavy metals in rice produced in Mazandaran province, Iran
Date: 2024Authors: Niknejad, H;Bandpei, B;Sarvestani, R;Mohseni-Bandpei, A;Saeedi, R;Abtahi, M;Gholami-Borujeni, F;
References: Journal of Food Composition and Analysis 128 106068
Keywords/Products: Concentric;ELAN;ICP;ICP-MS;Meinhard;Perkin Elmer;
The purpose of this study was to assess the health risk of the heavy metals (HMs) (arsenic [As], cadmium [Cd], chromium [Cr], copper [Cu], iron [Fe], lead [Pb], Manganese [Mn], and zinc [Zn]) in rice produced in Mazandaran province (Amol and Mahmoudabad), Iran. A number of 60 rice samples were randomly collected and analyzed for the HMs by ICP-MS. The non-carcinogenic and carcinogenic health risks of the HMs were probabilistically assessed based on Monte Carlo simulation in terms of hazard quotient/index (HQ/HI) and incremental lifetime cancer risk (LTCR), respectively. The average concentration of HMs in rice grains in the studied areas was ranked as follows: Fe > Zn > Mn > Pb > Cu > Cr > As > Cd. THQ?mi showed that non-carcinogenic risk for area residents was largely related to Pb (1.77), As (0.59), Fe (0.57) and Cr (0.41). The average HI values of the HMs in rice produced in Amol and Mahmoudabad were assessed to be 2.42 (1.10-4.14) and 1.91 (0.43-3.9), respectively. The average LTCR values of the HMs in rice were in the following order: Cd (3.46 × 10?4 [1.34 × 10?4 to 6.96 × 10?4] for Amol and 3.97 × 10?4 [1.35 × 10?4 to 9.57 × 10?4] for Mahmoudabad) > As (8.60 × 10?5 [1.47 × 10?5 to 2.42 × 10?4] for Amol and 1.04 × 10?4 [6.17 × 10?6 to 2.83 × 10?4] for Mahmoudabad) > Cr (5.71 × 10?5 [2.88 × 10?5 to 9.61 × 10?5] for Amol and 4.75 × 10?5 [1.59 × 10?5 to 8.69 × 10?5] for Mahmoudabad). The average total LTCR value of the HMs in rice was within the acceptable range (10?6 to 10?4). The findings showed that exposure to the HMs via rice consumption could threaten human health, and an appropriate strategy to reduce concentrations of the HMs in rice is needed.
Atmospheric aerosol chemistry and source apportionment of PM10 using stable carbon isotopes and PMF modelling during fireworks over Hyderabad, southern India
Date: 2024Authors: Attri, P;Mani, D;Satyanarayanan, M;Reddy, DV;Kumar, D;Sarkar, S;Kumar, S;Hegde, P;
References: Heliyon 10 e26746
Keywords/Products: Aerosol;ICP;ICP-MS;Meinhard;sample introduction;
This study examined the influence of fireworks on atmospheric aerosols over the Southern Indian city of Hyderabad during festival of Diwali using mass closure, stable carbon isotopes and the EPA-PMF model. Identification of chemical species in day and night time aerosol samples for 2019 and 2020 Diwali weeks showed increased concentrations of NH4+, NO3-, SO42-, K+, organic carbon (OC), Ba, Pb and Li, which were considered as tracers for fireworks. PM10 source apportionment was done using inorganic (trace elements, major ions) and carbonaceous (organic and elemental carbon; OC & EC) constituents, along with stable isotopic compositions of TC and EC. K+/Na+ ?1 and K+nss/OC > 0.5 indicated contribution from fireworks. High NO3-, NH4+, Na+, Cl- and SO42- suggested the presence of deliquescent salts NaCl, NH4NO3 and (NH4)2SO4. TAE/TCE >1 suggested H+ exclusion, indicating possible presence of H2SO4 and NH4HSO4 in the aerosols. Ba, Pb, Sb, Sr and Fe increased by 305 (87), 12 (11), 12 (3), 3 (2) and 3 (4) times on Diwali nights, compared to pre-Diwali of 2019 (2020), and are considered as metallic tracers of fireworks. ?13CTC and ?13CEC in aerosols closely resembled that of diesel and C3 plant burning emissions, with meagre contribution from firecrackers during Diwali period. The ?13CEC was relatively depleted than ?13CTC and ?13COC. For both years, ?13COC-EC (?13COC - ?13CEC) were positive, suggesting photochemical aging of aerosols during long-range transport, while for pre-Diwali 2019 and post-Diwali 2020, ?13COC-EC were negative with high OC/EC ratio, implying secondary organic aerosols formation. High toluene during Diwali week contributed to fresh SOA formation, which reacted with precursor 12C, leading to 13C depletions. Eight-factored EPA-PMF source apportionment indicated highest contribution from residue/waste burning, followed by marine/dust soil and fireworks, while least was contributed from solid fuel/coal combustion.
Wall loss of semi-volatile organic compounds in a Teflon bag chamber for the temperature range of 262-298?K: mechanistic insight on temperature dependence
Date: 2024Authors: He, L;Liu, W;Li, Y;Wang, J;Kuwata, M;Liu, Y;
References: Atmospheric Measurement Techniques 17 755-764
Keywords/Products: Aerosol;Meinhard;TR-30-A1;
. ???????Teflon bag chambers have long been used for investigating atmospheric chemical processes, including secondary organic aerosol formation. The wall-loss process of gas-phase species in Teflon bag chambers has typically been investigated at around room temperature. Recent laboratory studies started employing Teflon bag chambers at sub-273?K conditions for simulating wintertime and upper-tropospheric environments. However, temperature dependence in vapor-wall-loss processes of semi-volatile organic compounds (SVOCs) in a Teflon bag chamber has not been well investigated. In this study, we experimentally investigated wall-loss processes of C14-C19 n-alkanes in a 1?m3 Teflon bag for the temperature range of 262 to 298?K. Enhanced wall losses of the tested n-alkanes were observed following the decrease in temperature. For instance, 65?%??????? of C14 n-alkane was lost to the wall 15?h after injection at room temperature, while the corresponding value was 95?% at 262?K. The experimental data were analyzed using a two-layer kinetic model, which considers both absorption of gas-phase species to the surface layer of the Teflon wall and diffusion to the inner layer. The experimental data demonstrated that absorption of gas-phase species by the surface layer was enhanced at lower temperatures. The temperature dependence in absorption was well accounted for using the equilibrium-dissolution model of organic compounds to the Teflon surface by considering reduced saturation vapor pressure at lower temperatures. On the contrary, diffusion of n-alkanes from the surface to the inner layer slowed down at reduced temperatures. Mechanistic studies on these processes will need to be conducted in the future to quantitatively predict the influence of temperature-dependent wall-loss processes of SVOCs on laboratory experimental results.
Breastmilk mineral composition among well-educated mothers from Central Poland - Associations with maternal dietary intake, dietary patterns and infant psychomotor development
Date: 2024Authors: Zielinska-Pukos, MA;Michalska-Kacymirow, M;Kurek, E;Bulska, E;Grabowicz-Ch?drzy?ska, I;Weso?owska, A;Hamulka, J;
References: Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS) 83 127393
Keywords/Products: ICP;ICP-MS;Meinhard;sample introduction;
Maternal dietary habits could affect breastmilk mineral composition, which may influence infant development. Mineral dietary intake or supplementation slightly affects its breastmilk concentration. However, the intake of selected food groups or dietary patterns that reflect diet complexity could have a greater impact. Hence, the aim of the study was to assess breastmilk mineral composition at one, three, and six months of lactation among mothers living in urban area of Central Poland, as well as the evaluate maternal dietary determinants and associations with infant anthropometric and psychomotor development.The study was conducted among 43 healthy and exclusively breastfeeding mothers. In the first, third, and sixth months of lactation, we collected breastmilk samples and assessed the concentration of Ca, P, Zn, Fe, Se, Ni, As, Pb, and Cd using the ICP-MS method. Maternal dietary habits were evaluated by a food frequency questionnaire in the first month of lactation, whereas in the third and sixth by the three-day food record. Based on the collected data adherence to the Polish-adapted Mediterranean (Pl-aMED; 1 month) and the DASH diet (Mellen's Index; 3 and 6 months) was assessed. In the third and sixth months of lactation infant anthropometric parameters and the sixth month of lactation psychomotor development were evaluated.Breastmilk Se, Ni, As, Pb, and Cd levels were under the LOQ in all the breastmilk samples at all study visits. Median breastmilk mineral concentrations of Ca, P, Zn, and Fe in the first, third, and sixth months of lactation varied from 381.9 to 332.7 mg/L, 161.6 to 139.1 mg/L, 2.2 to 0.8 mg/L, and 0.26 to 0.17 mg/L, respectively. Maternal dietary intake and supplementation did not affect breastmilk Ca, P, Zn, and Fe. Pl-aMED scores were associated with breastmilk Ca (? = 0.489, 95% CI 0.180 - 0.799, p = 0.003) and Zn (? = 0.499, 95% CI 0.199 - 0.798, p = 0.002) in the first month of lactation, whereas no association with the DASH diet were observed in the third and sixth month of lactation. Breastmilk Fe in the third month was associated with infant motor development (? = 0.420, 95% CI 0.113 - 0.727, p = 0.009) in the sixth month of life, but no other associations with anthropometric or psychomotor development were observed. Moreover, we estimated that few infants meet their adequate intake (AI) requirements for P, Zn, and Fe.Our study showed that maternal adherence to Pl-aMED is a significant predictor of breastmilk Ca and Zn in the first month of lactation, which may be especially important considering that more than 75% of infants had inadequate Zn intake. Moreover, we found that breastmilk Fe positively influenced infant motor development, despite the majority of infants having inadequate intake. On the other hand, no infant had deficiency symptoms, which emphasizes the necessity to evaluate of AI norms for infants.
Performance of single-cell ICP-MS for quantitative biodistribution studies of silver interactions with bacteria
Date: 2024Authors: Gimenez-Ingalaturre, A;Abad-Álvaro, I;Goñi, P;Billimoria, K;Goenaga-Infante, H;Laborda, F;
References: Journal of Analytical Atomic Spectrometry 39 743-753
Keywords/Products: Concentric;Cytoneb;ICP;ICP-MS;Meinhard;
Single-cell inductively couple plasma mass spectrometry (SC-ICP-MS) method development for the study of silver interactions with bacteria to provide information about silver biodistribution in bacteria and spheroplasts.
Fractionation of selenium isotopes during biofortification of Saccharomyces cerevisiae and the influence of metabolic labeling with 15N
Date: 2023Authors: Mejia Diaz, LF;Karasinski, J;Wrobel, K;Corrales Escobosa, AR;Yanez Barrientos, E;Halicz, L;Bulska, E;Wrobel, K;
References: Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry 28 655-667
Keywords/Products: ICP;ICP-MS;Meinhard;
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.
Determination of Heavy Metal Content: Arsenic, Cadmium, Mercury, and Lead in Cyano-Phycocyanin Isolated from the Cyanobacterial Biomass
Date: 2023Authors: Galinyt?, D;Bal?i?nait?-Murzien?, G;Karosien?, J;Morudov, D;Naginien?, R;Baranauskien?, D;Šulinskien?, J;Kudlinskien?, I;Savickas, A;Savickien?, N;
References: Plants (Basel, Switzerland) 12 ~
Keywords/Products: ICP;ICP-MS;Meinhard;sample introduction;
Cyano-phycocyanin (C-PC) is a light-absorbing biliprotein found in cyanobacteria, commonly known as blue-green algae. Due to its antioxidative, anti-inflammatory, and anticancer properties, this protein is a promising substance in medicine and pharmaceuticals. However, cyanobacteria tend to bind heavy metals from the environment, making it necessary to ensure the safety of C-PC for the development of pharmaceutical products, with C-PC isolated from naturally collected cyanobacterial biomass. This study aimed to determine the content of the most toxic heavy metals, arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) in C-PC isolated from different cyanobacterial biomasses collected in the Kaunas Lagoon during 2019-2022, and compare them with the content of heavy metals in C-PC isolated from cultivated Spirulina platensis (S. platensis). Cyanobacteria of Aphanizomenon flos-aquae (A. flos-aquae) dominated the biomass collected in 2019, while the genus Microcystis dominated the biomasses collected in the years 2020 and 2022. Heavy metals were determined using inductively coupled plasma mass spectrometry (ICP-MS). ICP-MS analysis revealed higher levels of the most investigated heavy metals (Pb, Cd, and As) in C-PC isolated from the biomass with the dominant Microcystis spp. compared to C-PC isolated from the biomass with the predominant A. flos-aquae. Meanwhile, C-PC isolated from cultivated S. platensis exhibited lower concentrations of As and Pb than C-PC isolated from naturally collected cyanobacterial biomass.
Partitioning and Speciation of Lanthanides in the Magnetite (Hematite)-Hydrothermal Solution System at 450°C and 100 MPa
Date: 2023Authors: Smagunov, N;Lipko, S;Tauson, V;Belozerova, O;Babkin, D;
References: Geochemistry International 61 948-955
Keywords/Products: Concentric;Concentric nebulizer;ICP;ICP-MS;Meinhard;Quartz Nebulizer;sample introduction;
—First results of the experimental study of a hydrothermal multisystem including lanthanides (_Ln_) and Fe oxides (magnetite and hematite) are presented. _Ln_ concentrations in solutions and crystals were determined by ICP-MS and LA-ICP-MS, respectively. The _Ln_ partition and cocrystallization coefficients obtained are interpreted as the maximum estimates of “true” values corresponding to structurally bound admixture. It is shown that _Ln_ (except for Eu) are the compatible elements in hydrothermal magnetite; heavy _Ln_ (beginning with Tb) are compatible in hematite. The pronounced tendency of the increase of both coefficients with increasing _Ln_ atomic number beginning from Gd-Tb was established. This is of great importance when light to heavy Ln ratio is used as a typochemical guide for localization of ore source. The _Ln_-rich phases in association with magnetite and hematite were obtained. These phases have oxychloride (without Fe) and oxyhydroxide (with Fe) composition and exemplify the simultaneous occurrence of light and heavy _Ln_ within a single hydrothermal system due to the co-crystallization of phases selectively accumulating light and heavy lanthanides.
Wall loss of semi-volatile organic compounds in a Teflon bag chamber for the temperature range of 262-298 K
Date: 2023Authors: He, L;Liu, W;Li, Y;Wang, J;Kuwata, M;Liu, Y;
References: Preprints ~ ~
Keywords/Products: Aerosol;Meinhard;TR-30-A1;
. Teflon bag chambers have long been used for investigating atmospheric chemical processes, including secondary organic aerosol formation. Wall-loss process of gas-phase species in Teflon bag chambers has typically been investigated at around room temperature. Recent laboratory studies started employing Teflon bag chambers at sub-273 K conditions for simulating wintertime and upper tropospheric environments. However, temperature dependence in vapor wall-loss processes of semi-volatile organic compounds (SVOCs) in a Teflon bag chamber has not well been investigated. In this study, we experimentally investigated wall-loss process of C14-C19 n-alkanes in a 1 m3 Teflon bag for the temperature range of 262 to 298 K. Enhanced wall losses of the tested n-alkanes were observed following the decrease in temperature. For instance, 65 % of C14 n-alkane was lost to the wall 15 hours after injection at room temperature, while the corresponding value was 95 % at 262 K. The experimental data were analyzed using the two-layer kinetic model, which considers both absorption of gas phase species to the surface layer of Teflon wall and diffusion to the inner layer. The experimental data demonstrated that absorption of gas phase species by the surface layer enhanced at lower temperature. The temperature dependence in absorption was well accounted using the equilibrium dissolution model of organic compounds to the Teflon surface by considering reduced saturation vapor pressure at lower temperature. On the contrary, diffusion process of n-alkanes from the surface to inner layer slowed down at reduced temperature. Hence the relative importance of the surface and inner layers on wall-loss process changes with temperature. Mechanistic studies on these processes will need to be conducted in the future to quantitatively predict the influence of temperature-dependent wall-loss processes of SVOCs on laboratory experimental results.
Sp-ICP-MS and HR-CS-GFAAS as Useful Available Techniques for the Size Characterization and Speciation of Ionic and Nanoparticular Zinc in Cosmetic and Pharmaceutical Samples
Date: 2023Authors: García-Mesa, J;Morales-Benítez, I;Montoro-Leal, P;Lopez Guerrero, M;Vereda Alonso, E;
References: Available at SSRN ~ ~
Keywords/Products: Glass Nebulizer;ICP;ICP-MS;Meinhard;Type C;
Abstract Unavailable
Phase Transformations from a Local Structure Perspective
Date: 2023Authors: Wilson, CE;
References: Thesis ~ ~
Keywords/Products: Concentric;Glass Nebulizer;Meinhard;Optima;Perkin Elmer;POINT;
Phase transformations are commonly exploited in materials science for a multitude of technologies due to a coinciding property transition. However, the understanding of solid-solid phase transformations is still developing, especially from a local perspective (< 30 Å). A suite of characterization and analysis techniques both proceeding and preceding the phase and property transition provides structural information starting at two angstroms. Operando and in situ experimental methodologies have advanced to the point that these structural phase transformations can be observed throughout the entire transition. The development of these advanced experimental characterization techniques with respect to x-ray diffraction, and total x-ray scattering along with large dataset analysis methodologies elucidated highly detailed local structure information. An archetypal first-order metal-insulator transition (MIT) material, vanadium dioxide, was first investigated using these techniques which were then extended to the battery cathode material, titanium trisulfide. From these analyses, the Peierls-Mott hypothesis of MIT origin was supported and local vanadium oxidation upon increasing tungsten-substitution was found to instigate a decrease in the change in properties across the transition temperature. For titanium trisulfide, it was found that kinetically driven Li-entrapment is decreasing the overall gravimetric capacity retention leading to premature battery death.
Given the high intake of potatoes by the world population, reliable methodologies with very low limits of detection are needed for the determination of highly toxic elements such as arsenic. For that purpose, graphite furnace atomic absorption spectrometry could be considered one of the techniques of choice; notwithstanding the matrix effect prevented its application in arsenic determination in potatoes as the analytical signal was absolutely depleted. The potential interferent was searched among the mineral content. As a result, it was found that the interference presumably could be attributed to phosphate. Attempts to overcome the matrix interference by different sample digestion methodologies, chemical modification and temperature variation in the graphite furnace ashing and ashing / atomization stage respectively, were unsuccessful. Consequently, an alternative methodology for determining arsenic in potatoes using hydride generation microwave induced plasma optical emission spectrometry was developed. Limit of detection was 0.0030 mg kg-1 in fresh potatoes. The developed method is a robust, simple and low cost alternative for total arsenic safe monitoring of this highly consumed worldwide vegetable.
Date: 2023Authors: Zambra, R;Sixto, A;Pistón, M;Mollo, A;
References: Brazilian Journal of Analytical Chemistry ~ ~
Keywords/Products: Meinhard;
Given the high intake of potatoes by the world population, reliable methodologies with very low limits of detection are needed for the determination of highly toxic elements such as arsenic. For that purpose, graphite furnace atomic absorption spectrometry could be considered one of the techniques of choice; notwithstanding the matrix effect prevented its application in arsenic determination in potatoes as the analytical signal was absolutely depleted. The potential interferent was searched among the mineral content. As a result, it was found that the interference presumably could be attributed to phosphate. Attempts to overcome the matrix interference by different sample digestion methodologies, chemical modification and temperature variation in the graphite furnace ashing and ashing / atomization stage respectively, were unsuccessful. Consequently, an alternative methodology for determining arsenic in potatoes using hydride generation microwave induced plasma optical emission spectrometry was developed. Limit of detection was 0.0030 mg kg-1 in fresh potatoes. The developed method is a robust, simple and low cost alternative for total arsenic safe monitoring of this highly consumed worldwide vegetable.
Prep Signal
Date: 2023Authors: Sartor, S;Toaldo, IM;Panceri, CP;Caliari, V;Luna, AS;Bordignon-Luiz, JS;
References: prepsignal.com ~ ~
Keywords/Products: Meinhard;
The identification and quantification of individual polyphenolics in wine samples throughout the aging process were performed by high performance liquid chromatography with diode array detection (HPLC-DAD) (Shimadzu, Kyoto, Japan). For all polyphenolic compounds, analyte separation was achieved on a Shim-pack CLC-ODS end-capped reverse phase-column (4.6 x 250 mm, 5 µm) from Shimadzu. For the analysis, 20 ?L of samples were injected into the HPLC system. Sixteen phenolic compounds belonging to the subclasses of hydroxybenzoic acids, hydroxycinnamic acids, flavonols, flavan-3-ols, tyrosol and stilbenes were quantified in wine samples and their levels were monitored up to 12 months of over-lees aging. Sample preparation and HPLC analysis were performed according to Burin, Ferreira-Lima, Panceri, & Bordignon-Luiz (2014). In the procedure, wine samples were submitted to liquid-liquid extraction prior to injection into the chromatography system. The mobile phase A was water: acetic acid (98:2 v/v) and mobile phase B was water: acetonitrile: acetic acid (58:40:2 v/v/v). The gradient elution was as follows: 0-80 % solvent B for 55 min, 80-100 % B for 15 min and 100-0 % B for 5 min, with the flow rate set at 0.9 mL min-1 and total run time of 75 min. The detection was set at 280 mn for tyrosol, catechin and epicatechin, at 320 nm for caffeic, trans-caftaric, p-coumaric and ferulic acids, at 360 nm for myricetin, quercetin and kaempferol, and at 306 nm for trans- resveratrol. The separation of hydroxybenzoic acids (gallic, protocatechuic, syringic, vanillic and ellagic) was carried out using a binary mobile phase consisted of ultrapure water: acetic acid (98:2, v/v) (A) and acetonitrile: solvent A (80:20, v/v) (B). The elution gradient was as follows: 0-35 % B for 35 min, 35-0 % B for 3 min, with total run time of 38 min. The flow rate was 1.0 mL min-1 and the detection was set at 280 nm for all the compounds, with the exception of ellagic acid that was detected at 254 nm. The 3-O-monoglucoside anthocyanins (malvidin, cyanidin, delphinidin and peonidin) were determined according to Revilla, Pérez-Magariño, González-Sanjosé, & Beltrán (1999). A gradient elution programme was used with the mobile phase consisted of water: formic acid (90:10 v/v) (A) and water: methanol: formic acid (45:45:10 v/v/v) (B) as follows: 35-95 % solvent B for 20 min, 95-100 % solvent B for 5 min, 100-35 % solvent B for 5 min, with this maintained for 5 min for a total run time of 35 min. The flow rate was kept at 0.8 mL min-1 and the detection set at 520 nm.