Sequential Extraction Method Research Articles

A green and efficient technology for sequential extraction of lipid and paramylon from Euglena gracilis

Euglena gracilis is rich in nutrients and high-value metabolites. However, at present, most studies only extract the paramylon of E. gracilis, which is a waste of resources. In this study, a method of sequential extraction of lipid and paramylon from E. gracilis was studied, and the extraction conditions were optimized. Firstly, by optimizing the solid-liquid ratio, extraction time, extraction temperature and volume ratio of n-hexane to ethanol, the lipid extraction efficacy was increased from 73.0 % to 96.0 %. Next, paramylon was extracted from the E. gracilis residue. After optimizing the enzyme type, enzyme concentration, ratio of material to liquid and enzymolysis time, the protein removal rate was 91.3 %, the yield of paramylon was 58.3 % and the purity reached 89.3 %. Compared with the traditional method, this sequential extraction method was greener and more effective for the extraction of paramylon and lipids from E. gracilis, which can promote the comprehensive utilization of algae resources.

Assessing the Current Status and Proposing Solutions for Heavy Metal Management in the Saigon River Basin Sediments

The sediment is the final environment where heavy metals accumulate and directly impact the health of aquatic systems and humans.Therefore, the study was carried out to determine the total content and forms of heavy metals in the sediments at 13 locations in the Saigon River basin in rain and dry seasons of 2022. In addition, this research also assesses the pollution risk level and the correlation between heavy metals and physicochemical properties in the sediments. Chemical analysis was applied to determine the contributors of heavy metals while the geochemical calculation methods (hazard quotient (HQ), geo-accumulation index (Igeo), pollutant load index (PLI), individual contamination factors (ICF) and global contamination factors (GCF), risk assessment code (RAC)) were used to assess the pollution risk level in river sediments. The results show that Ag, Ba, Mn and Zn were metals with high pollution risks, especially in rain season. The results showed that the total concentration of heavy metals in sediments in rain season ranges from 109.92 to 4591.01 mg.kg–1 (Mn > Zn > Li > Ba > Ag > Cr > Cu > Pb) and in dry season from 0 to 3117.8 mg.kg–1 (Mn > Ag > Zn > Li > Ba > Cr > Cu > Pb). Applying the sequential extraction method, the metal forms of Ba, Cr, Cu and Li in the sediment samples are mainly residues (F5) (up to 76.53%), proving these elements dominated by natural sources. In contrast, the Mn extract composition was strongly influenced by human activity with exchange (F1) (>50%) and carbonate (F2) (>20%) components predominating. For Ag, Pb and Cu were mainly in organic form (F4). In dry season, the river sediments didn’t contain Pb because it didn’t carry away rainwater. In particular, Zn had a strong fluctuation between the extracted forms in rain and dry seasons, showing impacts from nature and humans sources. Besides, the statistical analysis results showed that pH affected Cu and Zn contents with a negative correlation, but did not detect the correlation between heavy metals and sand, clay, electrical conductivity (EC) in Saigon river sediments. The research results are foundational for the implementation and design of effective remediation strategies to prevent risks of river sediments degradation in the future.
 

A novel approach for the fractionation of organic components and microbial degraders in ADM1 and model validation based on the methanogenic potential

The anaerobic digestion model No 1 (ADM1), with fixed fractions of the substrate components, is currently used to simulate methane production during the anaerobic digestion (AD) of waste activated sludge (WAS). However, the goodness-of-fit for the simulation is not ideal due to the different characteristics of WAS from different regions. In this study, a novel methodology based on a modern instrumental analysis and 16S rRNA gene sequence analysis for the fractionation of organic components and microbial degraders in the WAS is investigated to modify the fractions of the components in the ADM1. The combination of Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and nuclear magnetic resonance (NMR) analyses were used to achieve a rapid and accurate fractionation of the primary organic matters in the WAS that was verified using both the sequential extraction method and the excitation-emission matrix (EEM). The protein, carbohydrate, and lipid contents in the four different sludge samples measured using the above combined instrumental analyses were 25.0 – 50.0%, 2.0 – 10.0%, and 0.9 – 2.3%. The microbial diversity based on 16S rRNA gene sequence analysis was utilized to re-set the initial fractions of the microbial degraders in the ADM1. A batch experiment was utilized to further calibrate the kinetic parameters in the ADM1. Based on the above optimization of the stoichiometric and kinetic parameters, the ADM1 with full parameter modification for WAS (ADM1-FPM) simulated the methane production of the WAS very well with a Theil's inequality coefficient (TIC) of 0.049, which was increased by 89.8% than that of the default ADM1 fit. The proposed approach, with its rapid and reliable performance, demonstrated a strong application potential for the fractionation of organic solid waste and the modification of ADM1, which contributed to a better simulation of methane production during the AD of organic solid wastes.

Chemical association and combustion behaviour of cadmium in coal of different mining fields using sequential and single step extraction methods

ABSTRACT This work sought to conduct the chemical association of a toxic metal (cadmium) in coal samples of various origins in Pakistan. For that purpose, a sequential extraction scheme recommended by the Community Bureau of Reference (BCR) has been carried out to know the chemical fractionation of Cd in different coal samples. Simultaneously a time saving vortex-assisted single-step extraction (VA-SSE) via the same experimental parameters conditions used in each fraction steps of BCR sequential extraction procedure (BCR-SE). The coal samples were collected from Thar coal (TCF) and Lakhra coal fields (LCF) of Sindh, Pakistan. The validity of BCR-SE and VA-SSE were checked by applying spiking standard addition procedure on real coal samples. The BCR-SE and VA-SSE were completed in 51 h and 1.0–2.0 min, respectively. In second phase determined the combustion behaviour of Cd or/amount of Cd in coal samples volatilise after heating in an electric furnace in laboratory at three temperature interim (200°C, 400°C and 900°C). The coal ash obtained at 900°C was put to three step sequential extraction method. The evaluated result showed that the total values of Cd in coal samples of block II of Thar coal field (TCF), Site I and Site II of Lakhra coal field (LCF) were found in the range of 3.42–4.43, 2.02–2.82 and 2.91–3.92 mg/kg, correspondingly. The final result indicated that the major chemical fraction of Cd was bound with organic phase of coal samples of both origins (about 40%). The evaluated data showed that 60–71% of Cd in coal samples was found in first three fractions, whilst about 29–40% of Cd was observed in residual. The extracted Cd concentrations in various chemical fractions of coal samples obtained through VA-SSE were 1.6–2.6%, higher than those values gained via BCR-SE (p < 0.04). The resulted data indicated that, after burning of coal samples at 900°C, about 63–69% of total Cd in coal samples of both mining areas was found in residual ash, while 31–34% was vaporised/volatilised out into the atmosphere.

Temporal transformation of indium speciation in rice paddy soils and spatial distribution of indium in rice rhizosphere

Indium is a potentially toxic element that could enter human food chains, including soil-rice systems. The submerged environment in rice paddy soil results in temporal and spatial variations in the chemical properties of the rice rhizosphere and bulk soils, expected to cause changes in indium's chemical speciation and consequently affect its bioavailability. Therefore, this study aimed to investigate indium speciation and fractionation in soils at different periods of rice growth under continuous submergence using X-ray absorption spectroscopy and a sequential extraction method. The predominant indium species were identified as indium-associated Fe hydroxide, and indium hydroxide and phosphate precipitates. The reductive dissolution of indium-associated Fe hydroxides led to the release of indium into the soil solution under continuous submergence of soils, and the released indium concentration decreased with time due to re-sorption and re-precipitation. Meanwhile, indium hydroxide was found to be the predominant species in rice rhizosphere using μ-X-ray absorption spectroscopy. The relative depletion of indium-associated Fe hydroxides in the rice rhizosphere was attributed to the low mobility of indium from bulk soil to rice rhizosphere and the root uptake of indium associated with Fe hydroxide around rice roots. Consequently, indium uptake by rice roots was lower during the reproductive and grain-ripening stage of rice growth. Understanding the behavior of indium will help develop a strategy to minimize uptake into crops in indium-contaminated paddy soils.

Calcium enhances phosphorus reclamation during biochar formation: Mechanisms and potential application as a phosphorus fertilizer in a paddy soil

Transformation of phosphorus (P) species during pyrolytic production of biochar from P-rich biowastes with a subsequent soil amendment is important to P reclamation. Aiming at increasing the content of plant-available P and restraining the formation of easily mobile P in pyrolysis product, this study used exogenous calcium ions (20 wt% CaCl2) addition prior to pyrolysis to regulate the pyrolytic transformation of P chemical fractions from sewage sludge and bone dreg. Results showed that active Ca catalyzed the decomposition of organic P to transform into inorganic orthophosphate. Based on Hedley’s sequential extraction method, this study found that addition of Ca ions remarkably reduced the content of soluble P, exchange P, Fe/Al bound P, and occluded P in biochar, while increased Ca bound P from 78 to 85% to 85–96%. Liquid 31P NMR indicated that exogenous Ca induced the crack of the P-O-P bond in pyrophosphate to become orthophosphates. It also explained why new orthophosphates including chlorapatite (Ca5(PO4)3Cl) and calcium hydroxyapatite (Ca10(PO4)6(OH)2) appeared in the Ca-composite biochar compared to pristine biochar. Combined with rapid P-release test in paddy soil (pH 6.27) and 30-days rice seedling growth test under flooded condition (10 wt% biochar addition ratio), it was confirmed that compared to pristine biochar, Ca-composite biochar released more P in paddy soil, but also promoted more P to be taken in by rice root and stalk. These results suggested that pretreating biowaste with Ca ion was a friendly approach to enhance P reclamation during biochar formation, making it a promising P fertilizer.

Improved Method of Background Value Determination for Sb and Cd in Freshwater Sediment—Insights from Controlling Factors on Spatial Variability

Variability in the distribution of natural total Sb and Cd in freshwater sediments leads to difficulties in background value (BV) determination. This study aimed to establish a method to determine BV more accurately by investigating the vertical distribution of Sb and Cd in sediment cores collected from a typical river in alluvial plain in China and revealed the factors that control the variation of Sb and Cd BV, which has not been studied in alluvial freshwater sediment. The results suggested that uncontaminated samples for BV calculation should be determined by statistical analysis as human and natural disturbance led to high variation in contamination depth, from <5 cm to >55 cm. The sequential chemical extraction method showed a considerable amount of non-residual fractions of Sb and Cd, which accounted for 48% and 43% of the total, respectively. Acid extractable Cd (16%) was associated to the limestone geology in the area. Fine particles which governed by sedimentary environment contained more natural Sb and Cd, as strong positive correlation was found between clay content and Sb concentration (r = 0.89, p < 0.01), as well as Cd concentration (r = 0.54, p < 0.01). Based on these findings, a method combined with standard deviation and geochemical method was established to calculate the BV of Sb and Cd, and counter maps were made to cover the variation of BV in the Taipu river sediment. The pollution level has been evaluated by the geoaccumulation index more accurately.

Methionine application at low phosphate level promotes root-to-shoot cadmium translocation by mobilizing weakly bound apoplastic cadmium in valerian (Valeriana officinalis L.)

Controlling the uptake and translocation of heavy metals in medicinal plants is crucial due to its strong impact on the safety and quality of derived medicinal plant products. This study investigated the effects of phosphate and methionine on the distribution and chemical forms of Cd in valerian (Valeriana officinalis L.) roots and shoots. Seedlings were grown for two weeks in a Cd-free nutrient solution containing either 400 or 1200 μM phosphate and then exposed for 10 days to 10 μM Cd either in combination with 400 μM or no methionine in the nutrient solution. Root Cd was partitioned into a symplastic and an apoplastic Cd fraction using a desorption procedure with EDTA. A sequential extraction method was applied to determine chemical forms in which Cd was retained in both roots and shoots. “Pectate- and protein-bound Cd” and HAc-soluble “Cd phosphates” were the dominant Cd forms in sequential extractions of both roots and shoots. Phosphate increased the HAc-soluble “Cd phosphate fraction” in the roots, but not in the shoots. Methionine did not affect this fraction, but strongly increased ethanol- and water-soluble Cd in roots and shoots. While it also increased the “pectate- and protein-bound Cd fraction” in the shoots, it decreased this fraction and the share of apoplastic Cd in the roots. The phosphate treatment reduced Zn accumulation in the roots but had no effect on Zn accumulation in the shoots, whereas Met increased shoot Zn. The results indicate that methionine induced root-to-shoot Cd translocation primarily by mobilizing weakly bound Cd to root cell walls at the low phosphate level. This could help limit Cd accumulation in valerian roots grown for medicinal use.

Combined forage grass-microbial for remediation of strontium-contaminated soil

Enrichment plants were screened from six forage grasses in this study to establish a complete combined forage grass-microbial remediation system of strontium-contaminated soil, and microbial groups were added to the screened dominant forage grasses. The occurrence states of strontium in forage grasses were explored by the BCR sequential extraction method. The results showed that the annual removal rate of Sudan grass (Sorghum sudanense (Piper) Stapf.) reached 23.05% in soil with a strontium concentration of 500 mg·kg−1. Three dominant microbial groups: E, G and H, have shown good facilitation effects in co-remediation with Sudan grass and Gaodan grass (Sorghum bicolor × sudanense), respectively. When compared to the control, the strontium accumulation of forage grasses in kg of soil with microbial groups was increased by 0.5–4 fold. The optimal forage grass-microbial combination can theoretically repair contaminated soil in three years. The microbial group E was found to promote the transfer of the exchangeable state and the reducible state of strontium to the overground part of the forage grass. Metagenomic sequencing results showed that the addition of microbial groups increased Bacillus spp. in rhizosphere soil, enhanced the disease resistance and tolerance of forage grasses, and improved the remediation ability of forage grass-microbial combinations.

Chemical Composition and Biological Activities of Lavandula coronopifolia Poir Extracts: A Comparison between Callus Culture and Native Plant

Nowadays, according to the development and high functions of in vitro cultivation, one of the questions that researchers are looking for is whether the characteristics and compositions of the obtained product meet the needs of the society or not. Therefore, this research was done aimed to compare the bioactive characteristics of callus and native plant aqueous extracts of Lavandula coronopifolia Poir. Thus, two different culture media were utilized for calluses’ growth. Extracts from these calluses and native plants were obtained using the sequential ultrasound-microwave assisted extraction (SUMAE) method. The extraction conditions were a constant temperature of 70°C ultrasound in 20 min at 250 W and 8 minutes at 800 W for microwave at 85°C. At first, results revealed that callus cultures were not able to produce any significant amounts of essential oil. Therefore, aqueous extracts obtained from calluses as well as the natural plant were examined in terms of antioxidant activity, total phenolic content, total flavonoid content, and antimicrobial activity. Moreover, their volatile components were detected with GC-MS. Both DPPH and FRAP techniques demonstrated that the callus on MS + Auxin had stronger antioxidant activity than the other callus and native plant. It also had the greatest total phenolic content. In terms of total flavonoid content, the native plant has the highest value. Generally, it can be concluded that the extract of callus on MS + Auxin has shown significant activity against the tested microorganisms than the other samples.

Effects of soil texture on trace metal concentrations and geochemical fractions in the soil of apple orchards (Çanakkale, NW Turkey)

ABSTRACT The effects of soil texture on trace metal concentrations and geochemical fractions in an apple orchard soils were investigated. For this purpose, soil samples were taken from the apple orchards with two different soil textures located on the same geomorphological unit in Çanakkale, Turkey. A wet digestion was used to determine total trace metal concentrations, and a sequential extraction method was used to determine geochemical fractions of the metals. According to average total concentrations of all metals, except Pb, were found to be significantly higher (p < 0.05) in clay soils. Sequential extraction analysis showed that potential mobile fractions were ordered as Cd (68.8%) > Pb (52.4%) > Cu (42.0%) > Zn (34.8%) > Ni (32.3%) > Cr (22.9%) in clay soils and as Cd (61.6%) > Pb (51.6%) > Cu (40.2%) > Zn (30.7%) > Ni (30.8%) > Cr (24.9%) in loamy soils. The results revealed that all metals, except Pb, in exchangeable/acid soluble, oxidizable and, potential mobile fractions were found to be significantly higher in clay soils (p < 0.05). It was figured out that clay contents played an effective role in total concentrations of metals and their distribution in geochemical fractions.

Determination of Selenium Speciation in High Se-Enriched Edible Fungus Ganoderma lucidum Via Sequential Extraction

Edible fungi are often used as an important selenium (Se) source to improve human daily Se intakes as food or Se supplements because of their strong ability to accumulate Se, in which Ganoderma lucidum was widely accepted in China. However, the existing Se speciation analysis methods such as protease K-based or trypsin-protease XIV-based, have low extraction rate and enzymatic hydrolysis rate (&lt;30%) on the Se-enriched edible fungi, resulting that it is impossible to effectively evaluate Se transformation and safety of Se-enriched edible fungi. In order to improve the extraction rate and enzymatic hydrolysis rates, 12 extraction methods (combination of buffer solutions and enzymes) including 4 two-step extraction methods and 8 three-step extraction methods were applied to extract Se from high Se-enriched Ganoderma lucidum (Total Se content 245.7 μg/g in dry matter (DW)) in the present study. The results displayed that one three-step sequential extraction method as aqueous solution extraction-pepsin extraction-trypsin extraction performed the best, by which the total Se extraction rate could reach 65%, the total Se enzyme hydrolysis rate was 40%, and the Se speciation was revealed as Selenite (63.6%), SeCys2 (20.1%), SeMeCys (14.8%) and SeMet (1.5%) in this high Se-enriched Ganoderma lucidum. This study offers a reliable and efficient method to evaluate the Se transformation and the Se safety in high Se-enriched edible fungi.

Influence of temperature change on the immobilization of soil Pb and Zn by hydrochar: Roles of soil microbial modulation

Considering the potential effect of the ambient temperature on soil microorganisms during heavy metal immobilization by hydrochar, 60 days of soil incubation was conducted to explore the impact of ambient temperature (5, 25, and 35 °C) on the immobilization of Pb and Zn by chitosan-magnetic sawdust hydrochar (CMSH) and magnetic chitosan hydrochar (MCH). The results showed that soil pH was relatively high and total organic carbon (TOC) was slightly lower in the 35 °C treatment. The diethylenetriaminepentaacetic acid (DTPA) available state content decreased significantly with the temperature increasing. Meanwhile, the ratios of stable Pb and Zn in the sequential extraction method proposed by the European Community Bureau of Reference (BCR) gradually increased with increasing temperature. The heatmap based on microbial community showed that elevated temperature not only favored the enrichment of metal-stable phyla, such as Chloroflexi, but was also involved in inhibiting the growth of Firmicutes, Actinobacteriota, and Proteobacteria. Meanwhile, different genera (Fonticella and Bacillus) in the Firmicutes phylum had distinct responses to temperature as well as to heavy metal immobilization effects. Subsequently, redundancy analysis confirmed that Chloroflexi and Fonticella were positively correlated with temperature and stable state metal content, while Actinobacteriota and Bacillus were negatively correlated with temperature and were positively correlated with DTPA available metal content. Moreover, Pb and Zn indicators displayed significant correlations for the dominant genera (R2 > 0.8, p < 0.02).

Occurrence Relationship between Sodium and Maceral Groups in Subbituminous Coal: A Case Study on Zhundong Coal and Shenfu Coal

The occurrence characteristics of sodium and its potential relationship with macerals in Zhundong coal, as well as in Shenfu coal with average sodium levels, are investigated in this study. A new five-step sequential extraction method was first conducted for determination. The occurrence status of sodium and its related macerals in samples was determined by microscope and SEM–EDS (scanning electron microscope–energy dispersive X-ray spectroscopy). Soluble sodium salts (H2O-Na) make up the primary proportion of sodium in Zhundong coal, at approximately 50%, while various sodium species are distributed in Shenfu coal with nonobvious differences. Inertinite contains more sodium than vitrinite does in both coals, and the highest enrichment degree of sodium was discovered in inertinite from Zhundong coal, which presented primarily as NaCl crystals (H2O-Na) in fusinite cells, with a local weight percentage of over 15%. More specifically, H2O-Na and insoluble Na both tend to enrich in fusinite. Additionally, it is found that maceral-rich products can be gathered using triboelectrostatic separation, and a portion of sodium can thus be removed from the coal by removing inertinite. This study may provide new insights and references regarding sodium removal from Zhundong coal.

Geochemical distribution and forms of phosphorus in the surface sediment of Netravathi-Gurupur estuary, southwestern coast of India

Estuaries are the most productive transition ecosystem and phosphorus (P) plays an important role in these ecosystems. Therefore, in the present study, sequential extraction method was used to determine the abundance of five sediment P fractions (calcium (Ca-P), Iron (FeP), aluminum (AlP), exchangeable (Ex-P) and organic (OrgP) bound P) in Netravathi-Gurupur estuary, India. Total phosphorus (TP) content varied from 435-810 mg/kg (non-monsoon) and 258–699 mg/kg (monsoon). Inorganic P was dominant part. Different P fractions followed similar order (Fe-P > Ca-P > Al-P > Org-P > Ex-P) with respect to seasons. FeP was dominant fraction, indicating probable anthropogenic stress. Sediment may act as source of P as bioavailable P constituted 40–69.2 % of TP. Molar ratio of OC to Org-P in sediment indicated terrestrial sources of organic matter. However, the estimated phosphorus pollution index were lower than one except a few cases indicating less ecological risk with respect to sedimentary TP load.

Sequential Downstream Process for Concurrent Extraction of Lutein, Phytol, and Biochemicals from Marine Microalgal Biomass as a Sustainable Biorefinery

In view of achieving the multi-product biorefinery model, this study strategically valorized the microalgal biomass for simultaneous production of two high-value products, lutein and phytol, along with value-added biochemicals such as protein, lipid, and carbohydrate by employing a systematic sequential extraction process. This sequential downstream process was carried out in two steps; first, the extraction of total pigments (chlorophyll and carotenoid) from the Chlorella variabilis biomass using methanol, followed by saponification and phase separation, resulted in simultaneous separation of lutein and phytol with a purity of 95.3 ± 1.2 and 94.4 ± 2.2%, respectively. Second, the depigmented biomass was sequentially valorized for the extraction of major biochemical compounds. In this step, three strategies, namely, I, IV, and VI, which were employed to extract protein (67.5 ± 0.7% recovery), lipid (76.4 ± 4.2% recovery), and carbohydrate (54.6 ± 0.8% recovery), respectively, as the primary product were found to be optimal in terms of their maximum recovery. Further, the impact of different sequential extraction methods on the composition of amino acids, sugars, and lipids was discussed and the suitability of the extracted biochemicals was critically examined for their application as aquaculture feed, bioethanol, and biodiesel production, respectively. This study also emphasizes the energy consumption by different unit operations that can be major energy sinks. Thus, this study presents an approach to developing an efficient biorefinery model, in which the commercially important products from microbial biomass are sequentially valorized to improve the asset value for the biorefinery industry.

The Geochemical and Environmental Characteristics of Trace Metals in Coastal Sediment Discharge off the Mailiao Industrial Zone of Central Western Taiwan

The geochemical fractions of trace metals in the coastal sediments of the central western Taiwan were examined, employing the Tessier sequential extraction method, and the metals contamination status of the analyzed sediments were also evaluated in the present study. Based on the metal fraction present in sediments, trace metals can be divided into three groups: (1) Al, Cr, Fe, Ni and Zn; (2) Cu and Pb and (3) Mn. In group (1) metal, the metals’ total concentrations were chiefly dominated by the residual fraction, exceeding 80% of the total concentration pool. In group (2) metal, the metals’ total concentrations were dominated by three labile fractions, carbonate, Fe-Mn oxides and organic, accounting for nearly 65% of the total pool, and the residual fraction contributed 35% of the total concentrations. Over 90% of Mn total concentrations were shared by three fractions, carbonate, Fe-Mn oxides and the residual fraction. The statistic results indicated that the total organic carbon contents in sediments played a more important role in influencing the metals contents in sediments. The contamination assessment results suggested that the Mailiao coastal sediments were minorly contaminated by trace metals. Lead should be paid more concerns because Pb total concentrations at some sediments exceeded the value (46.7 mg/kg) of effect range low, USA, and Pb was mainly present in the labile fraction.

Speciation of metals in soils of steppe landscapes affected by mining (Southern Urals)

Speciation of ore and accompanying elements (Cu, Zn, Fe, Ni, Pb, Cd, Cr, V, Ba, Sr) in steppe soils of the Transurals (vicinity of city of Sibay, Bashkortostan) was studied with sequential extraction method. Attention was given to change of elements’ speciation in area affected by mining (Cu-Zn deposit). The results are supplemented by chemical analysis of humic acids (isolated by alkaline extraction) and granulometric fractions. It was revealed that the soils of background areas are characterized by low mobility of studied elements and a relatively uniform distribution over soil profile. Residual fraction percentage (fraction’s share in element’s total content) is the highest. Percentage of exchangeable and carbonate fractions is insignificant (Sr and Ba are exceptions). Percentage of fraction of crystalline Fe hydroxides, reduceable and oxidizable fractions varies from shares of a percent to 15%. Cd stands out for a high percentage of oxidizable fraction (up to 30% of Cd total content) and relatively low percentage of residual fraction (up to 50%). Comparison of obtained results allows us to suggest that near objects of mining industry dust enriched with Cu, Zn, Cd, Pb and Sb comes to the surface. This leads to shard increase of Cu, Zn, Cd content in the upper layer of chernic horizon, change of these elements’ speciation and distribution among granulometric fractions. Increase of elements content is not only due to prevailing residual fraction; Cu, Zn, Cd of oxidizable fraction, reducible fraction and Fe hydroxides fraction significantly increase. Sharp increase of oxidizable fraction percentage (largely due to sulfides) is noted.

Potentially toxic elements in grapevine varieties and soil in Serbia

The accumulation of potentially toxic elements (PTEs) in agricultural soils and their subsequent uptake by plants, posing risks to agricultural products and con?sumers is of particular concern for investigation. Vineyard soils are especially vulnerable to pollution from various sources, including agrochemicals, fertilizers and surrounding polluting activities. This research is based on the BCR sequential extraction method to assess PTE speciation in vineyard soil samples. Additionally, it investigates the bioaccumulation of PTEs in grapevines (Cabernet sauvignon and Sauvignon blanc) and evaluates potential health risks for consumers of grapevine products based on each investigated PTE. The find?ings reveal that certain PTEs, Cd, Mn, Ba, Co, Pb and Cu exhibit significant mobility and bioavailability in vineyard soils, emphasizing the importance of continuous monitoring for food safety. The bioaccumulation potential, based on calculated biological accumulation concentration (BAC), exists for some elements, especially for Cu and Zn from easily avail?able soil phase. The human health risk assessment indicates that the consumption of grape?vine products poses minimal risk (HQ &lt; 1) to consumers. Anyhow, among the investigated PTEs, Ba and Cu have the highest HQs. This research contributes to a better understanding of PTE dynamics in vineyard environments, emphasizing the need for ongoing monitoring and control measures to ensure agricultural product safety and protect consumers? health.

Novel Magnetic-Bead-Assisted Sequential Extraction Method for Liquid Chromatography-Mass Spectrometry (MS)/MS of Components with Diverse Properties: Gastrin Determination as a Case Study

Sample preparation is the rate-limiting step in liquid chromatography-mass spectrometry (LC-MS)/MS-based clinical analysis when target analytes possess significantly different properties. Repeated solid-phase extraction (SPE) processes are typically required, resulting in low throughput and excessive consumption of labor, materials, and samples. In this study, we developed and validated a feasible and productive method to enrich target analytes with different properties during a single operation, while sufficiently removing matrix interferences to meet LC-MS/MS requirements. Gastrin determination was selected as the subject of this study. An automated magnetic-bead-assisted sequential extraction (MBASE) workflow was developed to simultaneously isolate nonsulfated gastrin-17 (G17ns), sulfated gastrin-17 (G17s), nonsulfated gastrin-34 (G34ns), and sulfated gastrin-34 (G34s) from human serum. It performs two different ion-exchange-based magnetic-bead extraction steps on one sample aliquot to produce one combined extract for LC-MS/MS analysis. When compared with the traditional SPE process, the MBASE workflow saves over 75% time and labor expenses as well as over 90% material cost, while providing even higher extraction efficiency. The MBASE LC-MS/MS method was validated as accurate and robust. Clinical sample test results demonstrated that the conventional chemiluminescence immunoassay method significantly under-estimated total gastrins in human serum, and the MBASE LC-MS/MS method could serve as an ideal tool to provide a comprehensive and accurate gastrin profile.