Extract Trace Research Articles

Trace reconstruction in system logs for processing with process mining

System logs contain information about the behavior of the system. To perform anomaly detection based on this log data, the normal behavior of the system must be learned. With process discovery a process model can be learned from log data. However, system logs do not fulfill the requirements that process discovery algorithms place on log data. To solve this problem, trace reconstruction is used to extract traces from the log data, which are then used for process discovery in a further step. This research proposal therefore proposes combining different methods for grouping log messages. A short experiment shows that the reconstruction of traces from simple log data is possible in principle.

Quantitative Detection of Zinc Oxide Nanoparticle in Environmental Water by Cloud Point Extraction Combined ICP-MS

The increasing usage of zinc oxide nanoparticles (ZnONPs) inevitably leads to their release into the environment. To understand their fate and toxicity in water systems, a reliable method for the quantitative analysis of ZnONPs in environmental waters is urgently needed to be established. In this study, a quantitative analytical method of ZnONPs in environmental waters was developed by cloud point extraction (CPE) combined inductively coupled plasma mass spectrometry (ICP-MS). To obtain high recoveries of ZnONPs, the CPE parameters including pH, surfactant concentration, salt concentration, bath temperature, and time were optimized. The results demonstrated that the addition of β-mercaptoethylamine could significantly reduce the interference of Zn2+ on the extraction of ZnONPs, while the CPE approach was not affected significantly by the typical environmental inorganic ion and ENMs (such as Au, TiO2, and Al2O3). The extraction method of ZnONPs with different diameters was also assessed, and satisfactory extraction efficiency was obtained. The results of ZnONP concentration in collected environmental water were in the range of [Formula: see text]-[Formula: see text] μg/L. And the recoveries of ZnONPs in different environmental waters were [Formula: see text]-[Formula: see text] at low concentration spiked levels (12.57-54.68 μg/L), demonstrating that it is efficient to extract trace ZnONPs from real environmental waters. This established method offered a reliable method for the quantitative determination of ZnONPs in environmental waters, which could further promote the study of the environmental behavior, fate, and toxicity of ZnONPs in an aqueous environment.

Hydrophobic deep eutectic solvent-based ultrasonic-assisted liquid-liquid micro-extraction combined with HPLC-FLD for diphenylamine determination in fruit

ABSTRACT In this paper, novel high extraction efficiency hydrophobic eutectic solvents (DESs), n-octanoic acid as a hydrogen bond donor (HBD) and menthol as a hydrogen bond acceptor (HBA), were selected from five hydrophobic DESs to extract trace diphenylamine (DPA) in fruits apple, pear and orange under ultrasonic-assisted liquid-liquid micro-extraction (UA-LLME) technology before high-performance liquid chromatography (HPLC) analysis. Working parameters such as the DESs type, molar ratio, extractant volume, and ultrasonic time of the LLME hydrophobic DESs technology were optimised. Average recoveries between 96% and 108% were obtained on actual samples. This method gave lower detection limit (LOD) than other existing methods due to combining the high-efficiency extraction of hydrophobic DES and high sensitivity of fluorescence detector. This method was sensitive and eco-friendly, and can be used for the determination of trace components in fruits.

Solid-phase extraction and microextraction of chlorophenols and triazine herbicides with a novel hydrazone-based covalent triazine polymer as the adsorbent

The current study dealt with the preparation and characterization of a novel hydrazone-based covalent triazine polymer (Hz-CTP). The Hz-CTP was synthesized by using 2,4,6-tris(hydrazino)-1,3,5-triazine (THTA) –with a C3 symmetry– as the knots and the terephthaldehyde –with a C2 symmetry– as the linkers. The synthesized Hz-CTP was used in dispersive solid-phase extraction of four different triazine herbicides and also fiber-based head-space solid-phase microextraction of chlorophenols (CPs). A series of characterizations showed that the Hz-CTP possessed large surface areas, high porosities, and high stability toward high temperatures. The adsorption performance and stability against moisture and thermal condition of the introduced CTP were examined by extraction trace concentration level of triazine herbicides and CPs in the water samples as model analytes. Triazine herbicides and CP analytes were determined with high-performance liquid chromatography coupled with UV–Vis detector and gas chromatography-flame ionization detector, respectively. Satisfactory results were achieved and prove the CTPs potential application in extraction.

Evaluation of silver nanocomposite polymer inclusion membranes (PIMs) for trace metal transports: Selectivity and stability studies

The presence of trace metals in polluted mine water remains a concern due to its adverse effects on human health. This paper evaluates a PVC-D2EHPA based PIM containing silver nanoparticles as a tool to extract and measure trace metals in polluted water. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), contact angle and water uptake measurements were used to characterise the PIMs. The contact angle measurements highlighted that the presence of AgNPs modified the membrane’s hydrophobic/hydrophilic character. The affinity of a PIM containing (40 w.t% D2EHPA, 10 w.t% AgNPs and 50 w.t% PVC) towards a range of divalent cations (Co2+, Ni2+, Cu2+, and Cd2+) in synthetic water solutions, based on the percentage recovery factor of the extracted metal ions, was found to follow the order; Cd2+ (94) > Cu2+ (87) > Ni2+ (78) > Co2+ (67). This order can be explained by the corresponding hydration energies of the metal cations. The stability of the PIM was compromised during repeated cycle operations despite an improvement of hydrophilicity with introduction of AgNPs. This was indicated by an appreciable leaching of the carrier (D2EHPA) and AgNPs in a 4:1 ratio. The silver nanocomposite PIM was tested in dam water, where no matrix effect was observed on metal ion transport efficiency. The obtained transport % efficiencies for the metal ions were Cd2+ (88), Cu2+ (80), Ni2+ (62), Co2+ (70) and Fe2+ (37) respectively. The newly synthesized PIM is a promising tool for transport of the target metals from water systems, however further studies are needed to improve the stability of both the carrier and nanoparticles in the membrane.

An octahedral magnetic metal organic frameworks for efficient extraction and enrichment of six pesticides with benzene ring prior to high performance liquid chromatography analysis

In this work, an octahedral magnetic metal organic frameworks composed of Fe3O4@NH2-MIL-101 was synthesized through simple solvothermal reaction for magnetic solid phase extraction (MSPE) of six pesticides with benzene ring in environmental water samples. The Fe3O4@NH2-MIL-101 was characterized by various techniques. The results showed Fe3O4@NH2-MIL-101 exhibits ultra-high surface area (1012.7 m2 g−1), large pore volume (0.64 cm3 g−1) and high magnetic responsivity (30.0 emu g−1), which can be used as an ideal adsorbent for rapid isolation and enrichment of target analytes. A sensitive method was developed by using Fe3O4@NH2-MIL-101-based MSPE coupled with HPLC (High performance liquid chromatography) with UV (Ultraviolate) detector. The linear range extended to 1000 µg L−1 was achieved, low limits of detection (S/N = 3) of 0.13–0.86 µg L−1 and good reproducibility (1.8–3.1%). The applicability of Fe3O4@NH2-MIL-101 was demonstrated for determining six pesticides in water samples with satisfactory recoveries at two spiking levels of 20.0, 80.0 µg L−1 were in the range of 70.5 to 119.8% with the RSDs less than 8.1%. These accurate experimental results by this method indicated that the novel Fe3O4@NH2-MIL-101 as a MSPE adsorbent was an attractive option for efficient extraction and enrichment trace pesticides in future.

A batch and cloud point extraction kinetic spectrophotometric method for determining trace and ultra trace amounts of Benzodiazepine drugs (Clonazepam and Nitrazepam) in pure and pharmaceutical preparations

Abstract Utilizing the batch Diazotization coupling reaction and the cloud point extraction kinetic spectrophotometric method, trace and Ultra trace amounts from reducing Nitrazepam and Clonazepam were evaluated by way of using 2,5-dimethoxyaniline as a new Chromogenic reagent to give colored products (red) in acidic medium which have a maximum absorption at 500 and 502 nm, respectively. In the work, the analytical data of batch and cloud point for Nitrazepam and Clonazepam depended on initial rate and fixation time. This involved concentrations of (0,3-9), (0.05-1.2), (0.5-10) and (0.025-1) µg mL−1, as well as molar absorptivity of (3.8×104), (3.1×105) (3.39×104) and (3.47×105) L mol−1 cm−1. According to our results, Sandall’s sensitivity were (0.0074), (0.0009), (0.0092) and (0.0009) µg cm−2, while detection limits were (0.055) and (0.069) µg mL−1, (8.4) and (8.5) ng mL−1. In addition, the measurements enrichment factors were (33.33) and (50), while preconcentration factors were (8) and (9.9), respectively. The reaction of Nitrazepam and Clonazepam with 2,5-dimethoxyaniline were a pseudo first order according to kinetic studies. The proposed methods are not affected by existence of excipients so the methods can be applied successfully for determination of Nitrazepam and Clonazepam in pharmaceutical preparations.

Regional geochemical zonation of cultivated floodplains–Application of multi-element associations for soil quality evaluation along the Ohře (Eger) River, Czech Republic

Floodplains are dynamic ecosystems wherein intensive farming can meet increased environmental concentrations and bioavailability of a number of trace elements. Therefore, the primary objective of this study was to investigate the partial digestion of selected trace elements in surficial soil samples (depth up to 40 cm) across a gradient of environmental conditions along the Ohře River and determining the elements of high priority, while also exploring their geographic variation. The established agrochemical testing of Czech soils provides a valuable resource to determine the geochemical differences of multi-element associations in cultivated areas (arable crops and hop fields) in periodically inundated areas in the catchment with a number of potential pollution sources. The topsoil samples were digested using the nitric acid (2 mol/L HNO3), analysed for trace elements (Be, Cd, Co, Cr, Cu, Ni, Pb, V, and Zn) using inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectroscopy (AAS), and for their total Hg content. Data (n = 130) were modelled against the sample location and cultivation using the log-ratio approach. The explanatory and inferential statistical tools (the Mantel's correlation test, PCA, MANOVA) adapted for compositions, combined with a simple spatial ranking and land-use information defined effective discriminating subcomposition (Cu–Hg–Ni) that were able to describe the changes of geochemical domains in floodplains and retained a decent representation (46%) of the entire compositional variability in our dataset. Mapping the Cu–Hg–Ni subcomposition using the RGB composite enabled to display the high-dimensional multivariate dataset with reduced information and enabled to discriminate spatial domains representing geochemical signatures related to changes in element inputs along the watercourse. The analysis of our results within the compositional framework showed a changing pattern of relative enrichment/depletion of the HNO3–extractable trace elements in which a regional contrast between groups of the chalcophile elements (Cu, Pb, Zn, and partly Cd), siderophile transition metals (Cr, Co, Ni, and V) and single elements (Hg, Be) was source-apportioned to the effect of point pollution sources (Hg, Ni, Cr, Co) as well as diffuse sources (Cu, Zn, Pb, Cd).

Synthesis of Fe3O4-based Magnetic Nanocomposites and Application in Pesticide Residue Detection

Magnetic nanomaterials are a new kind of nanomaterials with great potential application value. Recently, there have been many reports about the combination of magnetic nanomaterials and agricultural residue detection technology to establish a new detection method. Due to the special super paramagnetic, the large number of surface active sites, easy separation and recovery, the Fe3O4 magnetic nanocomposite material is commonly used in complex sample pretreatment on extraction and enrichment of the target compounds. By combining with the target substance in complex sample matrix and under the action of external magnetic field, the material can quickly, simply and efficiently enrich and extract trace substances in the sample. This paper mainly introduces the application of Fe3O4-based magnetic nanocomposites in the detection of pesticides and the main preparation methods of Fe3O4-based magnetic nanocomposites, including coprecipitation, microemulsion, photothermal chemistry and ultrasonic decomposition, hydrothermal reaction and sol-gel method.

Heterocyclic aromatic amines in doner kebab: Quantitation using an efficient microextraction technique coupled with reversed-phase high-performance liquid chromatography.

The safety of doner kebab as a traditional Middle East tasty food can threaten via the formation of dangerous compounds such as heterocyclic aromatic amines during heat process. In this regard, the current investigation was devoted to measuring of 4 HAAs (2‐amino‐3,4‐dimethylimidazo[4,5‐f]quinoline (MeIQ), 2‐amino‐3,8‐dimethylimidazo[4,5‐f]quinoxaline (MeIQx), 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP), and 2‐amino‐3‐methylimidazo[4,5‐f]quinoline (IQ)) in doner kebab samples with an innovative microextraction technique combined with high‐performance liquid chromatography. The limit of detection was in the range of 4.8 and 5.3 ng/g, while relative standard deviations were between 6.5% and 8.3%, and recoveries were calculated in the range of 89%–97%. The most and the least total mean values of HAA levels were 13.30 ng/g for MeIQx and 5.0 ng/g for IQ. The proposed method showed a high capability to extract trace amount of HAAs from a complex matrix such as doner kebab. Also, this technique is easy, high sensitive, selective, accurate and efficient.

A comparison of two reflectivity parametrizations in acoustic least-squares reverse time migration

ABSTRACTIn comparison with conventional reverse time migration (RTM), least-squares RTM (LSRTM) can improve imaging resolution and compensate irregular illumination caused by acquisition geometry and complex structures. Since proposed, as an advanced version of RTM, it has been applied a lot to improve resolution and balance amplitude in imaging. Generally, in LSRTM, there are two kinds of LSRTM reflectivity models: velocity perturbation related reflectivity model and normal-incidence reflection coefficient related reflectivity model. Each has its specific physical meaning and provides different inverted results. In this paper, we first give a brief review about the two different definitions. Then, we compare the differences of these two methods and build a mathematical relationship. In the definition related to reflection coefficient model, we rescale the defined reflectivity with background velocity. Also, in source wavefield reconstruction, we use an effective trick by moving file pointer to fetch data from disk to reduce the memory cost. Finally, we test these two LSRTM schemes using the Marmousi model. We observe that the two inverted reflectivities are different, although they both image the subsurface discontinuities well. We furthermore extract traces from the inversion results and compare them with the true reflectivity models, respectively, to verify the physical definitions of them.

Trace metal uptake by native plants growing on a brownfield in France: zinc accumulation by Tussilago farfara L.

Several human activities such as mining, smelting, or transportations lead to trace metal pollution in soil. The presence of these pollutants can represent environmental and organism health risks. Phytoextraction can be used to remediate trace metal-contaminated soils. It uses the plants' ability to remove trace metals from soil and to accumulate them in their shoots, which can then be harvested. We studied the spontaneous vegetation growing on a brownfield located in France. The use of native plants is interesting since spontaneous vegetation is already well adapted to the site's environmental conditions leading to a better survival and growth than non-native plants. Ten native plant species were sampled, and the Cr, Cu, Cd, Ni, Pb, and Zn concentrations present in their shoots were measured. In order to determine the plant's capacity to extract trace metals from the soil, the bioconcentration factor (BCF) was calculated for each plant and trace metal. Plants with a BCF greater than 1 are able to accumulate trace metals in their shoots and could be a good candidate to be used in phytoextraction. Results underscored one new accumulator plant for Zn, Tussilago farfara L., with a BCF value of 3.069. No hyperaccumulator was found among the other sampled plants. Our preliminary study showed that T. farfara is able to accumulate zinc in its shoots. Moreover, this native plant is a pioneer species able to quickly colonize various habitats by vegetative multiplication. That is why T. farfara L. could be interesting for zinc phytoextraction and could be worth further studies.

Fe3O4 nanoparticles coated with double imprinted polymers for magnetic solid phase extraction of lead(II) from biological and environmental samples.

Double imprinted polymer coated magnetic nanoparticles were fabricated with 4-nm size ZnO nanoparticles acting as the sacrifice templates, which were co-imprinted with template Pb(II) ions. After template removal, abundant transfer pores derived from ZnO nanoparticles were left around the selective adsorption sites derived from Pb(II) ions. The magnetic sorbent exhibit good selectivity, rapid adsorption kinetic and large adsorption capacity for Pb(II). They were used to extract trace Pb(II) followed by graphite furnace atomic absorption spectrometry detection. After the optimization of extraction conditions, following merits are found: (a) rapid extraction (10min), (b) high preconcentration factor (100 fold), (c) sensitive detection with the detection limit of 9.4ng·L-1, and (d) low relative standard deviation (6.9%) at a level of 50ng·L-1 of Pb(II) analyzed 7 times. The method was employed in extraction and quantification of trace Pb in biological and environmental samples with satisfactory recoveries of 87.5-104%. Graphical abstractDouble imprinted polymer coated magnetic nanoparticles (MNPs@DIP) were fabricated and used for extraction of Pb(II) followed by graphite furnace atomic absorption spectrometry (GFAAS) detection. The method was successfully applied for the determination of Pb in environmental and biological samples.

Facile preparation of reduced graphene oxide/ZnFe2O4 nanocomposite as magnetic sorbents for enrichment of estrogens

Reduced graphene oxide/ZnFe2O4 (rGO/ZnFe2O4) nanocomposite was facile prepared and applied as magnetic sorbent for the extraction of estrogens including 17β-estradiol, 17α-estradiol, estrone and hexestrol from water, soil, and fish samples prior to HPLC analysis. The rGO/ZnFe2O4 nanocomposite was characterized by scanning electron microscope, Fourier transform-infrared spectroscopy, X-ray diffraction, and vibrating sample magnetometer. The experimental parameters affecting the efficiency of magnetic solid-phase extraction (MSPE) including the amount of material, extraction time, pH, temperature, desorption solvents, desorption time, and desorption solvent volume were investigated respectively. With the developed method, good linearity was observed in the range of 0.05–500 ng/mL with the correlation coefficients (R2) between 0.9978 and 0.9993. The limits of detection (S/N = 3) and limits of quantification (S/N = 10) were achieved at 0.01–0.02 ng/mL and 0.05 ng/mL, respectively. The enrichment factors were calculated as the range of 241–288. Using rGO/ZnFe2O4 nanocomposite as the sorbent, the developed MSPE followed by HPLC analysis, was applied to analysis of estrogens in river water, soil and fish samples. The method has the potential application in the extraction and preconcentration ultra trace compounds in complex matrices, such as environmental and biological samples.

Extraction of chromium (VI) in water samples by dispersive liquid–liquid microextraction based on deep eutectic solvent and determination by UV–Vis spectrophotometry

ABSTRACT In this research, a simple, green, sensitive and fast method was developed based on deep eutectic solvent dispersive liquid-liquid microextraction (DES-DLLME) to extract trace amount of Cr(VI) from water samples followed by spectrophotometry determination via microcell. The new DES solvent was prepared by mixing phenol as hydrogen bonding donor and benzyltriethyl ammonium chloride as hydrogen acceptor at 50ºC for 5 min. The impact of various factors in complexation and microextraction steps were evaluated and optimised in detail. Under optimum conditions, calibration graph was linear in the range of 5.0–200 µg L−1. The limit of detection (LOD), the limit of quantification (LOQ), enrichment factor and relative standard deviation were obtained 1.5 µg L−1, 5.0 µg L−1, 73 and 5.01%, respectively. Finally, the proposed method was successfully employed for determination of Cr(VI) in water and wastewater samples and satisfactory recoveries (≥90%) was obtained.

Attapulgite/hydrophilic molecularly imprinted monolithic resin composite for the selective recognition and sensitive determination of plant growth regulators in cucumbers

In this study, through in-situ polymerization process, a novel composite of attapulgite/hydrophilic molecularly imprinted monolithic resin (AT/HMIMR) were prepared in pipette tips for extraction trace plant growth regulators in cucumbers. In the preparation procedure, fibrillar attapulgite nanoparticles were embedded to increase extraction capacity, polyethyleneglycol-6000 was employed as a dual-function porogen, that acted as both the structure-directing agent of the HMIMR and the attapulgite dispersant. N-(1-naphthyl) ethylenediamine dihydrochloride was used as a dummy template to accurate quantification on extraction procedures. Experimental parameters of AT/HMIMR for extracting plant growth regulators from cucumbers were optimized, and the results showed that the recoveries of ranged from 92.4% to 101.1% with relative standard deviations ≤ 6.5% (n = 3). Considering its microporous monolithic column structure, multiple adsorption mechanism, and specific selectivity, AT/HMIMR shows promise for applications that require specific recognition for the analytes in real complex samples.

Three-dimension Point Cloud Technology and Intelligent Extraction of Trace Evidence at the Scene of Crime

Three-dimensional (3D) point cloud technology is a kind of high-tech for the extraction of trace evidence from crime scenes. It is also an artificial intelligence technology for criminal justice investigation and diagnosis with great development prospects. It is one of the frontier issues in the field of criminal science and technology research. The purpose of this paper is to explore and analyze how to use 3D point cloud technology to extract trace evidence of crime scenes on the basis of understanding 3D point cloud technology, and to discuss the intelligent features of 3D point cloud trace evidence extraction. The principle and characteristics of 3D point cloud technology are introduced and described by the method of comparison and example. According to the technical characteristics of laser scanning, the methods and steps of extracting trace evidence from crime scenes are designed, and the overall workflow is given. This paper analyzes the intellectualization of 3D point cloud technology for trace evidence extraction from the perspective of the fusion of technology and perception, and draws some conclusions through simple practical description. Research shows, trace evidence extraction based on 3D point cloud technology is the full embodiment of digitalization and intellectualization of crime scene investigation. Doing a good job in information collection, data sample database construction, human-computer interaction platform design, and the data and knowledge of crime scene diagnosis experience are the basis for the development of this intelligent technology. In addition, with the different characteristics of different crime scenes, the improvement and innovation of the 3D laser scanning method is also an important work in the future.

Performance and Resource Utilization of FUSE User-Space File Systems

Traditionally, file systems were implemented as part of operating systems kernels, which provide a limited set of tools and facilities to a programmer. As the complexity of file systems grew, many new file systems began being developed in user space. Low performance is considered the main disadvantage of user-space file systems but the extent of this problem has never been explored systematically. As a result, the topic of user-space file systems remains rather controversial: while some consider user-space file systems a “toy” not to be used in production, others develop full-fledged production file systems in user space. In this article, we analyze the design and implementation of a well-known user-space file system framework, FUSE, for Linux. We characterize its performance and resource utilization for a wide range of workloads. We present FUSE performance and also resource utilization with various mount and configuration options, using 45 different workloads that were generated using Filebench on two different hardware configurations. We instrumented FUSE to extract useful statistics and traces, which helped us analyze its performance bottlenecks and present our analysis results. Our experiments indicate that depending on the workload and hardware used, performance degradation (throughput) caused by FUSE can be completely imperceptible or as high as −83%, even when optimized; and latencies of FUSE file system operations can be increased from none to 4× when compared to Ext4. On the resource utilization side, FUSE can increase relative CPU utilization by up to 31% and underutilize disk bandwidth by as much as −80% compared to Ext4, though for many data-intensive workloads the impact was statistically indistinguishable. Our conclusion is that user-space file systems can indeed be used in production (non-“toy”) settings, but their applicability depends on the expected workloads.

Room temperature and sensitive determination of haloanisoles in wine using vacuum-assisted headspace solid-phase microextraction

Headspace solid-phase microextraction (HSSPME) is a widespread technique used to extract trace amounts of haloanisoles from wine samples. A major challenge to overcome is the high ethanol content in wines that affects the solubilities of haloanisoles and reduces their headspace abundance. To overcome this obstacle and meet sensitivity requirements, reported HSSPME procedures typically suggest heating the wine samples and/or sampling for extended times. The present work proposes the use of vacuum-assisted HSSPME (Vac-HSSPME) to accelerate the extraction kinetics whilst sampling at room temperature. Although ethanol affected the physico-chemical properties of the target analytes, these changes were not sufficient to prevent the positive effect of vacuum on HSSPME sampling. To demonstrate the benefits of adopting the vacuum approach, Vac-HSSPME and regular HSSPME methods were independently optimized and the results were compared at all times. The effect of ethanol under each pressure condition was also discussed. Under the optimum conditions found, Vac-HSSPME sampling for 30 min at room temperature at 25 °C yielded lower detection limits (0.13 to 0.19 ng L−1) than those obtained with regular HSSPME sampling for 30 min at 55 °C (0.26 to 0.76 ng L−1). The proposed Vac-HSSPME method was successfully applied to quantify haloanisoles in bottled red wines and a discussion on the effect of wine volatiles was included. The standard addition method was used to minimize matrix effects. The increase in total pressure due to the presence of ethanol and other volatile wine components did not reduce the positive effect of vacuum on HSSPME. Nonetheless, in accordance to past HSSPME methods, the limits of detection and quantification were affected due to the noise level increase and analyte interaction with matrix. The proposed Vac-HSSPME procedure was applied to twelve bottled red wines and one sample was found positive on 2,4,6-trichloronanisole.

Development of a Rapid and Simple Digestion Method of Freshwater Sediments for As, Cd, Cr, Cu, Pb, Fe, and Zn Determination by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES): An Evaluation of Dilute Nitric Acid

ABSTRACT In this study, a simple and rapid methodology based on the hot-plate digestion method using dilute nitric acid solution was used to extract trace metals (such as As, Cd, Cr, Cu, Pb, Fe, and Zn) from freshwater sediments. The concentrations of the elements were determined using inductively coupled plasma-optical emission spectrometry (ICP-OES). The factors (temperature, nitric acid concentration, and volume) affecting the digestion method were optimized using one-factor-at-a-time (OFAT) or univariate methodology, and the optimization process was carried out using freshwater sediment certified reference material (CRM015). The optimal conditions for temperature, nitric acid concentration, and time in the method were 180°C, 10 mL of 5 mol L−1 HNO3, and 45 min, respectively. Under optimum conditions, the limit of detection (LOD) ranged between 0.02 and 0.08 µg L−1 and the limit of quantification (LOQ) ranged from 0.07 and 0.27 µg L−1. In addition, the method detection limits (MDLs) and method quantification limits (MQLs) were 0.10–0.17 and 0.30−0.57 µg g−1, respectively. The overall accuracy of the method determined by recovery of the trace elements in the CRMs ranged from 98 to 111% with the precision ranging from 1.4 to 5.8%. The method was successfully applied for the determination of target metals from real freshwater sediment samples.