Decomposition Of Samples Research Articles

Kinetic parameters of thermal decomposition of biofuels and its oil-containing composites

The kinetic features of the decomposition of fuel pellets formed from birch phloem and its composites with the addition of oil-containing waste (OCW) were studied by methods of thermogravimetric analysis carried out in various atmospheric conditions. The characteristic temperature ranges of thermal decomposition of the materials from which pellets are formed were identified, the rates of mass loss and activation energy at the main stages of thermal decomposition were evaluated, and the combustion indices of composite compositions were determined to identify the possibility of using such compositions as alternative fuels. By evaluation of activation energies for each stage of sample decomposition, the limiting influence of certain stages on the process of thermal destruction was established.

The experience of iron determination in technogenic materials with a high copper content by the redox titration method: case study of the waelz slag

Redox titration is one of the most common classical methods widely used in practice for the determination of total iron. A well-known procedure ISO 2597-1 (GOST 32517) includes the decomposition of a sample with dissolution, the reduction of Fe3+ to Fe2+ using a SnCl2 solution and its titration with a K2Cr2O7 solution in the presence of sodium or barium diphenylaminosulfonate as an indicator. We propose to use potassium tetrahydroborate KBH4 as a reducing agent for Fe3+ to Fe2+ instead of SnCl2 to modify a titrimetric method of total iron determination. The features of the well-known and considered methods are studied when using sintering for sample decomposition during the analysis of a large number of samples. Application of the developed method for the analysis of standard samples and technogenic materials with a high copper content, namely, Waelz slag showed a satisfactory accuracy and reproducibility of the obtained values of the total iron content. The results obtained indicate the possibility of the application of this method to the iron determination in the samples with a high copper content without an additional step of the iron separation from copper. A high productivity of the analysis (apart from the absence of the separation stage) is achieved due to the simplicity of the reduction process occurred at room temperature, no need for the control of the added amount of the reducing agent, and the possibility of holding the solutions for a long time before the titration. These advantages along with the no need for using toxic mercury compounds during the analysis make the method attractive for the analysis of a large number of samples.

Flame retardant polyurethane foam prepared from compatible blends of ammonium ligninsulfonate-based and zinc alginate

Abstract Zinc alginate (ZnAlg) was prepared and subsequently employed to modify ammonium ligninsulfonate-based polyurethane foams (PUFs). A range of analytical techniques, including thermogravimetry, integral programmed decomposition temperature, activation energy, smoke density, cone calorimetry and scanning electron microscopy, were employed to characterise the modified PUFs. The results demonstrated that the PUFA15Z5 (15 % ammonium lignin sulfonate and 5 g ZnAlg) with the lowest mass loss exhibited the second-highest sample decomposition temperature (T50 %), second-highest peak temperature (TMAX2), IPDT and activation energy. Furthermore, the PUFA15Z5 sample exhibited the smallest smoke density (23.11) and the highest light transmittance (67.11 %). The peak heat release rate, total heat release, smoke production rate, total smoke release and four fire risk assessment indicators of the PUFA15Z5 were the lowest, while its carbon residue was the densest. The results demonstrated that the PUFA15Z5 exhibited the most favourable thermal stability, flame retardant properties and the lowest smoke toxicity. These findings provided a valuable reference for subsequent biomass-based flame retardant modified polyurethane foams (PUFs).

Nanocomposite polyphenyleneoxide with amino-functionalized silica: structural characterization based on thermal analysis

AbstractA polymer nanocomposite based on sulfonated polyphenylene oxide with amino-functionalized mesoporous silica was designed, synthesized, and tested as a new material for proton exchange membrane (PEM preparation. Characterization of the intermediate and final products of synthesis was realized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and thermal analysis. Broadband Dielectric Spectroscopy (BDS) was used to determine dielectric properties including ionic conductivity. Thermogravimetric analysis has provided important information regarding the composition and thermal stability of the three compounds, subject to thermal degradation: 1) the amino-silica with cetyltrimethylammonium bromide (CTAB) template inside the pores (MS-NH2I), 2) the mesoporous amino-silica after removing the template (MS-NH2II) and 3) the polymer nanocomposite (sPPO-MS-NH2). The thermal decomposition of the composite samples occurs in three stages: in the first, up to 150 °C, water and organic solvents were lost; the second stage, between 200-300 °C, was due to breaking the organic functionalities (-NH2, amino and -SO3H, sulfonic acid), and the third stage, above 400 °C was due to polymer chain degradation. The final residue at 700 °C reflects the contribution of inorganic silica. The proton conductivity, for polymeric (sPPO) and composite (sPPO-MS-NH2) membranes was determined from BDS dates, both in dry and hydrated states. For dried samples, the higher values of proton conductivities were: 0.16 mS cm−1 (sPPO, 70 °C) and 0.03 mS cm−1 (sPPO-MS-NH2, 120 °C), and the higher values of proton conductivity increased for the hydrated samples with two orders of magnitude: 36.5 mS cm−1 (sPPO, 40 °C) and 22.4 mS cm−1 (sPPO-MS-NH2, 50 °C). However, the proton conductivity is still dependent on the hydration state, even for the composite membrane.

Design and development of thermo-electromagnetic system for spinodal decompositions of FeCrCo alloys

Permanent magnets are essential components of electromechanical devices. Majority of magnets are used in permanent magnet motors that have extensive application in relation to energy efficiency and sustainability like electric vehicles. This research is aimed for efficient manufacturing of FeCrCo permanent magnets. Electromagnets could be utilized for the generation of continuous magnetic field to use in number of manufacturing processes. A two-pole electromagnet, comprising of two solenoids each having 2200 turns of copper wire, was developed. The system was designed to produce magnetic field up to 10 kilo Gauss for spinodal decomposition of FeCrCo alloy samples under thermomagnetic treatment process. Being rare earth free alloys, FeCrCo magnet is gaining research focus as an alternative magnetic alloy for advanced applications. The electromagnetic system design was refined and confirmed by using the Finite Element Method. The experimental values, of magnetic field generated by the two-pole electromagnet setup, were well close to the simulation results. The magnetizing setup was utilized to treat the FeCrCo magnetic alloy samples simultaneously at high temperature (700 °C) and magnetic field (7 kilo Gauss). This thermo-magnetic setup helped to improve the metallurgical structures of FeCrCo to grow and develop more efficiently. Treated samples of FeCrCo alloy demonstrated enhanced magnetic properties due to effective spinodal decomposition. The improvement in magnetic properties was attributed to the elimination of retained alpha phase and formation of more alpha-1 phase.

Feasibility of matrix solid-phase dispersion combined with HR-CS FAAS for determination of copper in milk-based infant foods

This study proposes, for the first time, the development of an analytical method using the matrix solid-phase dispersion (MSPD) for extraction of copper from infant formulas and milk-based foods for further determination using high resolution-continuum source flame atomic absorption spectrometry (HR-CS FAAS). MSPD parameters were investigated, and by employing a 0.25 g sample, 0.25 g of diatomaceous earth as a solid support, 1 mol/L HNO3 as the extraction solution, and 1 min of blending, higher agreements with reference values were obtained. The limit of detection of the method was 0.35 µg/g. Accuracy was assessed by comparing the results using the following methods: i) proposed method (MSPD/HR-CS FAAS); and ii) decomposition of samples by microwave-assisted digestion (MAD) and quantification by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS). The MSPD extracts were also quantified using HR-CS GFAAS. No significant difference was found between the results. The agreements ranged from 95 to 103 %, and no significant difference was observed between the results. Copper concentrations ranged from 0.40 to 3.8 μg g−1 using the proposed method, with relative standard deviations lower than 10 %. The proposed method proved to be efficient for the determination of copper in infant formulas and milk powder, offering advantages such quickness, simplicity, low cost, low energy consumption, reduced waste generation (due to the use of an aqueous extraction solution), utilization of materials from renewable sources (diatomaceous earth as a solid support), and minimized analyst exposure when compared to conventional sample preparation methods. These attributes align with the principles of Green Analytical Chemistry.

Revisiting Li-CO2/O2 battery chemistry through the spatial distributions of discharge products and their oxidation behaviors

Li-CO2/O2 batteries present a promising strategy for CO2 conversion and energy storage, yet the complexity of discharge products poses challenges for revealing their oxidation. Here, we simulate the influences of various properties of Li2CO3 and/or Li2O2 on the decomposition pathway by comprehensively analyzing the singlet O2 (1O2) and gas components (O2 and CO2) generated during electrochemical oxidation. Our results show that no matter Li2CO3 or Li2O2, the decomposition of samples with small size and poor crystallinity produces less 1O2 and more gas product. Especially, small and poorly crystalline Li2CO3 triggers the concurrent decomposition of Li2CO3 and C, while large and highly crystalline Li2CO3 favors the solo decomposition pathway. Furthermore, the 1O2 yield can be most inhibited at a Li2CO3/Li2O2 ratio of 50 %. After clarifying the nature of Li2CO3 and/or Li2O2 oxidation, the spatial distributions of the oxygen discharge product in Li-CO2/O2 batteries were observed by scanning transmission X-ray microscopy (STXM). Li2CO3 is mainly distributed in the interior of large aggregates with high crystallinity. Poorly crystalline Li2O2 appears as small particles or coats on the surface of Li2CO3. Combined with multi-dimensional information of the discharge products and simulation results, the oxidation behaviors of the discharge products in Li-CO2/O2 batteries are reacquainted.

Anomaly detection method for urban river water quality based on background model prediction using three-dimensional fluorescence

Abstract Three-dimensional fluorescence spectroscopy has great potential for detecting water quality anomalies in urban rivers and protecting against organic pollution. However, current detection methods inadequately address critical application scenarios, such as fluctuations in river water background, low concentration of pollutants, and the fluorescence peaks overlap between pollutants and background. In this paper, a fluorescence spectrum feature extraction method which is effective for the above scenarios was proposed. The proposed method involves a sequential process. First, the original spectrum undergoes preprocessing using a novel method. Next, an alternating residual tri-linearization technique is applied to establish a predictive model for river water spectrum changes. Subsequently, the background model is utilized for spectrum decomposition and reconstruction of the test sample. This reconstructed spectrum is then used to derive the residual spectrum by comparison with the original. Finally, frequency domain features are extracted from the residual spectrum to enable classification, while the background model undergoes real-time updates. In the three meaningful scenarios mentioned above, the accuracy of the proposed method for anomaly detection reached 99%, 82%, and 98%, respectively. Our accuracy is higher than several typical benchmark methods.

Chemical Processing Development for Radioactive Minerals Processing Facility: A Circular Economy Model

The minerals and metals industries are vital in the world’s economy, yet their use of resources and waste generation pose considerable issues. The circular economy is a concept that establishes the foundation for economic operations that are carried out to run sustainably and to promote economic welfare, which in turn leads to an improvement in environmental quality. This paper offers a comprehensive literature analysis on the principles and efficacy of circular economy in mineral processing, specifically focusing on radioactive minerals. This research aims to develop a circular economy model that preserves resources, reduces waste production, and complies with regulatory rules on radioactive waste management. The study outlines a clear and structured circular economy model consisting of four modules: sample preparation, decomposition, partial extraction, and total precipitation. Each module integrates energy efficiency, heat recovery, renewable energy, water reuse, and chemical recycling. The validated model provides a roadmap for implementing circular economy principles in processing radioactive materials, contributing to achieving sustainable development goals. The government's agenda in pursuit of the Nationally Determined Contribution (NDC) can be aided by this model. This study suggests that reducing resource use and the volume of material, energy, and waste generated by technological processes can be achieved while still maintaining quality. That concept brings about a change in the mindset of designing a mineral processing installation. Based on the result of this study, further study may be focused on implementing strategies for each module of the studied object.

Study of the dielectric properties of decomposing materials during heating

The dielectric properties of materials when heated at ultrahigh frequencies are determined by methods based on the use of waveguide cavity resonators. However, as the sample is in the closed volume during measurements, the dielectric properties of destructive material thus determined can contain errors attributed filling of the resonator volume and depositing products of the sample decomposition on the internal conducting surfaces of the resonator. We present the results of studying the dielectric properties of destructive materials under heating in waveguide resonator cavity using methods that exclude the impact of destruction products on the accuracy of measurement. To reduce the influence of destructive vapors rising from the surface of the sample during the destruction process, additional thin quartz plates, placed on the sample surface were used. In addition, cuvettes with a lid were also used to prevent destruction products from entering the resonator volume. A method for taking into account the effect of plates and cuvettes in calculating the dielectric constant and dielectric loss tangent of a material sample when heated in a cavity resonator is presented. Changes in the dielectric properties of a composite material consisting of quartz fabric impregnated with an aluminochromophosphate binder and fiberglass laminate made of quartz fabric impregnated with a phenol-formaldehyde binder were studied in a temperature range above the onset of the destruction (up to temperatures at which loss of the structural strength of the material is observed). The developed method can be used in studying the thermophysical properties of destructive materials to assess changes in their dielectric characteristics under operation conditions of high-temperature heating.

Studying the Process of Phosphogypsum Recycling into a Calcium Sulphide-Based Luminophor.

Currently, one of the most important problems of environmental protection is the deep and complex processing of mineral raw materials. This problem is especially relevant when processing substandard ores and production waste, one of which is phosphogypsum. This study examines the process of CaSO4/CaS composite material formation during the reduction of phosphogypsum with citric acid. The composite structure formation mechanism is proposed. The resulting materials are characterized using various methods, including X-ray diffraction (XRD), transmission electron microscopy, the Scherrer method, thermogravimetric analysis (TGA), and FT-IR spectroscopy. The reduced sample emits orange radiation in the range of 500-750 nm with a quantum yield of 0.17. Experimental results showed that the sample decomposition process in the solid state consisted of two components with a predominant contribution from the long-lived component (~46 ns). The optimal conditions for producing luminescent materials by reducing phosphogypsum with citric acid were determined: a heat treatment temperature of 1073 K, a holding time of 60 min, and a reducing agent mole fraction of 37%. It was found that an increase in temperature with a simultaneous decrease in heat treatment time, as well as a decrease in temperature with a simultaneous increase in heat treatment time, led to a decrease in the luminescent properties of the synthesized material compared to optimal values. The results can be used to develop technology for recycling large-tonnage waste from the chemical industry into luminescent materials.

Natural Hazards in a Changing World: Methods for Analyzing Trends and Non‐Linear Changes

AbstractEstimating the frequency and magnitude of natural hazards largely hinges on stationary models, which do not account for changes in the climatological, hydrological, and geophysical baseline conditions. Using five diverse case studies encompassing various natural hazard types, we present advanced statistical and machine learning methods to analyze and model transient states from long‐term inventory data. A novel storminess metric reveals increasing European winter windstorm severity from 1950 to 2010. Non‐stationary extreme value models quantify trends, seasonal shifts, and regional differences in extreme precipitation for Germany between 1941 and 2021. Utilizing quantile sampling and empirical mode decomposition on 148 years of daily weather and discharge data in the European Alps, we assess the impacts of changing snow cover, precipitation, and anthropogenic river network modifications on river runoff. Moreover, a probabilistic framework estimates return periods of glacier lake outburst floods in the Himalayas, demonstrating large differences in 100‐year flood levels. Utilizing a Bayesian change point algorithm, we track the onset of increased seismicity in the southern central United States and find correlation with wastewater injections into deep wells. In conclusion, data science reveals transient states for very different natural hazard types, characterized by diverse forms of change, ranging from gradual trends to sudden change points and from altered seasonality to overall intensity variations. In synergy with the physical understanding of Earth science, we gain important new insights into the dynamics of the studied hazards and their possible mechanisms.

Synthesis of lignin-based carbon/graphene oxide foam and its application as sensors for ammonia gas detection

The present study highlights the integration of lignin with graphene oxide (GO) and its reduced form (rGO) as a significant advancement within the bio-based products industry. Lignin-phenol-formaldehyde (LPF) resin is used as a carbon source in polyurethane foams, with the addition of 1 %, 2 %, and 4 % of GO and rGO to produce carbon structures thus producing carbon foams (CFs). Two conversion routes are assessed: (i) direct addition with rGO solution, and (ii) GO reduction by heat treatment. Carbon foams are characterized by thermal, structural, and morphological analysis, alongside an assessment of their electrochemical behavior. The thermal decomposition of samples with GO is like those having rGO, indicating the effective removal of oxygen groups in GO by carbonization. The addition of GO and rGO significantly improved the electrochemical properties of CF, with the GO2% sensors displaying 39 % and 62 % larger electroactive area than control and rGO2% sensors, respectively. Furthermore, there is a significant electron transfer improvement in GO sensors, demonstrating a promising potential for ammonia detection. Detailed structural and performance analysis highlights the significant enhancement in electrochemical properties, paving the way for the development of advanced sensors for gas detection, particularly ammonia, with the prospective market demands for durable, simple, cost-effective, and efficient devices.

Rapid and Complete Digestion of Refractory Geological Samples Using Ultrafine Powder for Accurate Analyses of Trace Elements.

Complete sample digestion is a prerequisite for acquiring high-quality analytical results for geological samples. Closed-vessel acid digestion (bomb) has typically been used for the total digestion of refractory geological samples. However, the long digestion time (4-5 days) and insoluble fluoride complexes still pose challenges for digesting refractory geological samples using this approach. In this study, an efficient and simplified digestion technique combining ultrafine powders from planetary ball milling with bomb digestion was developed for trace element analysis of refractory geological samples: peridotite and granitoid. The method shows two significant improvements compared with previous approaches. (1) By performing dry planetary ultrafine milling, the initial 200 mesh peridotite (<74 μm) could be reduced to 800 mesh (<20 μm) in 6 min at a ball-to-powder mass ratio of approximately 15 using 3 mm tungsten carbide milling balls. (2) Complete peridotite and granitoid dissolution were achieved in approximately 2 h, 60 times faster than what is achievable using previous methods (2 h vs 120 h). Moreover, ultrafine powders effectively suppressed insoluble fluoride formation during bomb digestion. A suite of peridotite and granitoid reference materials were measured to evaluate the stability of this method. This efficient, simple, and reliable sample digestion method could benefit geological, food, environmental, and other fields requiring solid sample decomposition via wet acid, fusion, combustion, or dry ashing.

Structural Characterisation of End-of-Life Cement–Asbestos Materials from Lithuania

Asbestos is a widely used name for natural silicate minerals with fibrous properties. Asbestos minerals were one of the most popular and cheapest raw materials used in the construction industry in the past when they was used in the form of cement–asbestos composite material. Nowadays, we know that asbestos possesses carcinogenic properties. Due to this fact, asbestos was banned in many countries including Lithuania. All asbestos-containing materials are considered waste and stored in special landfills, which causes significant environmental pollution. One of the methods proposed to solve the asbestos problem may be thermal treatment. In the present study, asbestos-containing wastes in the form of cement–asbestos materials were examined. These asbestos-containing materials were characterised via chemical analysis (XRF) connected with mineralogical phase analysis with powder X-ray diffraction (XRD) as well as scanning electron microscopy (SEM). The thermal decomposition of samples was studied via differential thermal analysis (DTA) and thermogravimetric measurements with evolved gas analysis (TG–EGA). It was found that thermal treatment is a possible way to destroy asbestos contained in cement–asbestos wastes and convert it into new mineral phases. The work also compared the obtained characteristics of asbestos waste with the characteristics of waste produced in other countries.

Teaching Experimental Instrumental Analytical Chemistry Are we forming professionals, training operators or illuding students (and ourselves)?

Teaching Experimental Instrumental Analytical Chemistry Are we forming professionals, training operators or illuding students (and ourselves)?

Impact of Component Correlation on Probabilistic Seismic Responses of Steel Frames by Modifying Non-Positive Definite Correlation Matrices

ABSTRACT This paper studies the effects of spatial correlation between the structural components on probabilistic seismic performance of steel moment resisting frames, using extended incremental dynamic analysis (IDA) method to consider the effects of aleatoric uncertainties caused by ground motion records. In this probabilistic assessment, a combination of Latin hypercube sampling (LHS) and Cholesky decomposition (CD) methods are utilized to take the epistemic uncertainties of the numerical model into account. In case the target correlation matrix is not positive definite, two powerful optimization algorithms are employed to find the closest positive definite correlation matrix.

Novel method for chlorine determination in biofuel lipid feedstock by coupling a total sample introduction system (hTISIS) to an inductively coupled plasma tandem mass spectrometry (ICP-MS/MS)

BackgroundChlorine concentrations above 1 mg kg−1 in lipid feedstocks for biofuel production can generate corrosion issues in the different refining units as well as catalyst deactivation by clogging or fouling. To reach accurate analyses by inductively coupled plasma (ICP) techniques at low concentration levels, dilution in organic solvents rises as a simpler and more straightforward sample preparation methodology than conventional sample decomposition procedures (e.g., microwave-assisted acid digestion). However, matrix effects and the impact of the Cl chemical form on the signal must be overcome to obtain accurate results. ResultsIn this work, the high temperature torch integrated sample introduction system (hTISIS) operated at 350 °C is coupled to an inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) for the determination of Cl in lipid biofuel feedstock samples diluted in xylene and these results are compared with those reported by a conventional sample introduction system. Under optimal conditions of the hTISIS-ICP-MS/MS configuration, matrix effects are efficiently overcome (recovery values ranged from 101 to 104%) as well as the effect of the Cl chemical form on the signal for 6 organochloride compounds. Thus, an external calibration approach can be set to carry out the quantification of this element in real samples. The method is successfully validated, obtaining a good agreement in the Cl concentration reported in a standard reference material (SRM NIST 1634c) and also by comparing the concentration results obtained by external calibration and standard addition approaches in two biofuel feedstock samples. Significance and noveltyThe hTISIS coupled to an ICP-MS/MS system is used for the first time to overcome not only matrix effects but also the impact of the Cl chemical form in biofuel feedstock samples. This novel method, with a limit of quantification (LOQ) of 7.1 μg kg−1, give access to an accurate Cl determination in all kind of lipid feedstocks for clean fuel production.

Coprecipitation as a One-Step Se Separation for Determination of Isotope Ratios Completed with Revised Uncertainty Evaluation.

This study introduces a simplified purification method for analyzing 82Se/78Se isotope ratios in diverse natural samples using hydride generation MC-ICP-MS. Unlike the thiol resin method, which is time-consuming and sensitive to the concentrations of reagents used at individual stages, our proposed alternative is quicker, simpler, and robust. The procedure involves coprecipitation of selenium with iron hydroxide and dissolution in hydrochloric acid. Combining hydride generation and a second cleanup stage achieves sufficient purification for Se isotope ratio measurements. The method is efficient, taking 3-4 h after sample decomposition, utilizing common reagents [HCl, Fe(NO3)3, NH4Cl] without evaporation or clean lab conditions. Results on 82Se/78Se isotope ratios in various matrices are presented, comparing them with literature data. All isotopic results have been subjected to a newly proposed state-of-the-art approach to uncertainty estimation dedicated to isotope ratio measurements. The approach is based on applying Monte Carlo simulations with consideration of different samples' results normalized by the expected value. By doing that, we obtained estimated uncertainty for any Se sample with the influence of particular measurements on the final estimation included. We employ a Monte Carlo simulation-based uncertainty estimation approach for isotope ratio measurements, providing estimated uncertainty for each selenium sample.

Mineral Composition of Rice, Carrots, and Chayote after Microwave-Assisted Decomposition using Diluted Nitric Acid

Carrots, chayote, and rice are foods widely consumed by the Brazilian population, so developing analytical methods that allow elemental characterization becomes extremely important. In this work, the sample decomposition method is proposed to prepare samples (raw and cooked) of rice, carrots, and chayote using dilute nitric acid. The samples underwent microwave-assisted acid decomposition (HNO3/H2O2) for subsequent determination by ICP OES for metals Al, Cd, Cr, Cu, Fe, and Pb and flame spectrophotometer for K and Na. Two decomposition methods were used. Method 1: 260 and 500 mg of sample, 3.5 mL of HNO3 1 mol L-1, 1.0 mL of 30% m/m H2O2 and 3.5 mL of ultrapure water. Method 2: 260 and 500 mg of sample, 5.0 mL of 1 mol L HNO3-1, 2.5 mL of 30% m/m H2O2 and 0.5 mL of ultrapure water. A factorial design (22) was also performed to know the effects of some variables on digestion efficiency. Based on the accuracy study using certified reference materials and the analysis of residual acidity and dissolved organic carbon, the condition that presented the best decomposition results was using 5 mL of HNO3 0.5 mol L-1 and 2.5 mL of 30% H2O2 for 100 mg of sample. Quantification limits ranged from 0.14 (Cr) 3.4 mg kg-1 (Pb), and the correlation coefficient was close to one in all cases. It was also observed that the cooking process increased the concentration of Al, Cd, and Cr and decreased Cu and K for all foods.