Electrothermal Atomic Absorption Spectrometer Research Articles

Magnetic solid-phase extraction using metal–organic framework-based biosorbent followed by ligandless deep-eutectic solvent-ultrasounds-assisted dispersive liquid–liquid microextraction (DES-USA-DLLME) for preconcentration of mercury (II)

A novel magnetic biosorbent was prepared for preconcentration and extraction of Hg (II). Magnetic nanoparticles (Fe3O4@SiO2-NH2) were deposited on a metal–organic framework (HKUST-1). It was used as a proper platform for immobilization of a thymine-rich aptamer (Apt-Fe3O4@SiO2-NH2@HKUST-1). Characterization of the biosorbent was performed by various methods (XRD, FT-IR, SEM, and TGA). Mixing of biosorbent with the sample solution resulted in efficient selective binding of Hg (II) to Apt-Fe3O4- SiO2-NH2@HKUST-1. After separation with a magnet and then releasing Hg (II), further preconcentration was carried out by dispersive liquid–liquid microextraction (DLLME). In this step, a hydrophobic and low density deep – eutectic solvent (DES-1, l-menthol and salicylic acid in a molar ratio of 4:1) was used as extractant and complexing agent for Hg (II). Ultrasound bath was used for efficient dispersion of DES-1 in sample solution. After centrifugation and phase separation, DES-rich phase was introduced to an electrothermal atomic absorption spectrometer for determination of Hg (II) at 253.7 nm. An unprecedented enrichment factor (EF) of about 2400 was obtained by the proposed procedure. Under the optimized conditions, the dynamic linear range of 2–120 µg L−1 (R2 = 0.998). Limit of detection (LOD) and limit of quantification (LOQ) for Hg (II) were 0.34 ng mL−1 and 1.13 ng mL−1, respectively. Intra- and inter-day precision of the method were calculated (3.68% and 3.80%, respectively) for the determination of 1.0 µg L−1 of Hg (II) as relative standard deviation (RSD%). The sorbent capacity (Qe) was 156 µg mL−1 Hg (II). The proposed procedure was successfully applied to the determination of trace amounts of Hg (II) in several real samples.

Investigation of cadmium and lead contents of boron minerals and boron waste by electrothermal atomic absorption spectrometer

In this study, Cd and Pb were determined and investigated in the most abundant boron minerals such as colemanite, tincal, ulexite and boron waste existed in Turkey using electrothermal atomic absorption spectrometer. Graphite furnace temperature program for Cd and Pb determinations in samples was optimized in the absence or presence of palladium (Pd) and nickel (Ni) + Pd matrix modifier mixture. Pd + Ni modifier mixture was found to be more suitable for both Cd and Pb. The ashing temperatures for Cd and Pb obtained 600 °C and 1100 °C, respectively, in the presence of Ni + Pd mixture. Limits of detection and limits of quantification values for Cd and Pb in the absence or presence of Ni + Pd modifier mixture were determined. Accuracy and precision of the method proposed were checked by analyzing the standard reference materials (Montana Soil 2711 and Estuarine 1646a). Cd and Pb in boron minerals were performed under optimized experimental conditions.

Evaluate the adverse impact of metal oxide on workers of different age groups that engage with gas metal arc welding process: health risk assessment.

Immense epidemiological studies have been indicated about adverse effects of the welding fumes on the health of the welders, especially respiratory problems and other physiological disorders. The different types of welding mechanisms produce aerosols/fumes that contain different metals including chromium (Cr) and manganese (Mn). In the present study, the welders of two age groups (adolescents and adults) were selected; simultaneously the age-matched adolescents and adults belong to nonindustrial area as referents/control subjects. Biological samples (scalp hair) were collected from welders and referents, along with analyzed for Cr and Mn by electrothermal atomic absorption spectrometer, prior to acid digestion. To evaluate the occupational exposure on the health of the workers, the clinical features and biochemical parameters of selected population (exposed and non-exposed age-matched groups) were also carried out. The resulted data indicated that the concentrations of Mn and Cr were significantly higher in scalp hair samples of welders as compared to referent subjects (p < 0.01), verifying the absorption/exposure of both metals produced in welding fumes. The high prevalence of anemia and stomach disorder was observed in adolescent than adult welding workers. The incidence of asthma and related symptoms was elevated in adult welders than in younger boys. The neurological problems were particularly observed in aged welders > 50years, might be due to long time exposure of welding fumes contains different toxicant especially Mn in ill ventilation system of workshops.

A simple dilution method for the direct determination of trace nickel in crude oil with a miniaturized electrothermal atomic absorption spectrometer

A simple procedure for the direct determination of trace nickel in crude oil samples has been proposed using a miniaturized electrothermal atomic absorption spectrometer (ETAAS).

Evaluation the Weekly Intake of Some Wild Edible Indigenous Mushrooms Collected in Different Regions in Tunceli, Turkey.

The quantity of some essential and non-essential elements of wild edible mushroom samples collected from Tunceli Province of Turkey was determined by using flame and electrothermal atomic absorption spectrometer after microwave digestion. The method accuracy was corrected using standard reference material (NIST SRM 1547-Peach Leaves). The essential element concentrations of analyzed mushroom samples were determined in the range of 0.036-0.563 mg kg-1 for calcium, 1.28-2.55 mg kg-1 for magnesium, 0.054-0.188 mg kg-1 for sodium, 1.00-4.57 mg kg-1 for copper, 212-480 mg kg-1 for iron, and 75-151 mg kg-1 for zinc but cobalt and chromium were not detected. Based on results, there were statistically significant differences between the element contents of analyzed mushroom species. Consequently, according to this study results, the weekly intake and target hazard quotient values of the elements show that the consumption of these mushrooms does not threaten human health. Graphical abstract.

High-resolution continuum-source electrothermal atomic absorption spectrometer for simultaneous multi-element determination in the spectral range of 190–780 nm

We have built a prototype atomic absorption spectrometer with an electrothermal atomizer and continuum light source for simultaneous multi-element determination.

Method development for the determination of bromine via molecular absorption of barium monobromide by high-resolution continuum source molecular absorption spectrometry

A challenging novel method was developed for the determination of bromine via molecular absorption of barium monobromide (BaBr) using a high-resolution continuum source electrothermal atomic absorption spectrometer (HR-CS ETAAS).

Validation of a method for quantification of Lead, Chromium, Magnesium, Zinc &Copper in human blood and serum using Atomic Absorption Spectrometry

The quality of analytical data coming from the analysis of biological samples like blood, serum and human hair is of fundamental importance for judging the limit of contaminants. Since this analysis is exposed to errors due to sampling, sample preparation and instrument, it is important to validate the analytical methods used for such measurements. A method for quantification of lead, chromium, copper, magnesium and zinc in blood and in serum using electrothermal and flame atomic absorption spectrometer was established. Full validation was done to ensure the suitability of the developed method for the purpose of analysis. The main parameters evaluated in the validation study were the limit of detection (LOD), limit of quantification (LOQ), linearity range, accuracy, precision and expanded uncertainty of the measurement results of in case of each element. The results obtained revealed that the analytical method is valid for the analysis of biological samples.

Chromium in Postmortem Material

Recently, considerable attention has been paid to the negative effects caused by the presence and constant increase in concentration of heavy metals in the environment, as well as to the determination of their content in human biological samples. In this paper, the concentration of chromium in samples of blood and internal organs collected at autopsy from 21 female and 39 male non-occupationally exposed subjects is presented. Elemental analysis was carried out by an electrothermal atomic absorption spectrometer after microwave-assisted acid digestion. Reference ranges of chromium in the blood, brain, stomach, liver, kidneys, lungs, and heart (wet weight) in the population of Southern Poland were found to be 0.11–16.4 ng/mL, 4.7–136 ng/g, 6.1–76.4 ng/g, 11–506 ng/g, 2.9–298 ng/g, 13–798 ng/g, and 3.6–320 ng/g, respectively.

Application of modified cloud point extraction method for the chromium speciation in artificial saliva extracts of different snuff products

A modified cloud point extraction method (m-CPE) was developed for the speciation of chromium species (Cr3+ and Cr6+) in artificial saliva extracts (ASE) of snuff products. In this method, Cr3+ was complexed with 8-hydroxyquinoline, which was trapped in nonionic surfactant (Triton X-114), prior to analyzed by electrothermal atomic absorption spectrometer (ETAAS). Whereas, the total extractable Cr was determined by reducing Cr6+ to Cr3+ using Na2SO3 as a reducing reagent. Several parameters were optimized for the developed m-CPE. Under the most favorable conditions, enrichment factor, enhancement factor and limit of detection for the proposed method were 60, 134 and 0.04μgL−1, respectively having relative standard deviation <5%. Health risks associated with the intake of total Cr in snuff products was also assessed. Estimated daily intake of Cr via sniffing 10g/day of dry and moist snuff products was found below the maximum tolerable daily intake whereas the calculated risk for cancer due to Cr was observed in the acceptable range of 10 E−6–E−4.

Ultrasonic assisted dispersive liquid-liquid microextraction method based on deep eutectic solvent for speciation, preconcentration and determination of selenium species (IV) and (VI) in water and food samples

A novel ultrasound-assisted liquid phase microextraction (UALPME) based on environmental friendly extractants, deep eutectic solvent (DES) was first time presented for speciation of selenium. In present study, five DES solvents of different composition was prepared and used as efficient extractive medium for hydrophobic chelate of Se(IV) with 3,3′-Diaminobenzidine (DAB). The total inorganic Se species were determined after pre-reduction of Se(VI) to Se(IV), prior to applying developed method. The concentration of Se(VI) was calculated by the difference of Se(IV) values and total selenium contents. The concentration of Se in DES rich phase was measured with electrothermal atomic absorption spectrometer (ETAAS). The effects of different parameters on extraction efficiency of study analyte, including pH, ligand concentration, type and volume of DES, sonication time, volumes tetrahydrofuran and aqueous samples were examined. At the optimum conditions, limit of detection and quantification, preconcentration factor, and relative standard deviation (RSD %) were determined as 4.61ngL−1, 15.4ngL−1, 50% and 4.1%, respectively. The accuracy of the presented method was confirmed by analysis of certified reference material and standard addition method for different water and ice tea samples. The developed method was effectively applied to real water and food samples.

Application of portable tungsten coil electrothermal atomic absorption spectrometer for the determination of trace cobalt after ultrasound-assisted rapidly synergistic cloud point extraction

In this work, ultrasound-assisted rapidly synergistic cloud point extraction (UARS-CPE) was firstly established and combined with a portable tungsten coil electrothermal atomic absorption spectrometer (W-coil ET-AAS) for preconcentration and determination of trace cobalt. As a new instrument, the application of the portable W-coil spectrometer was expanded through the coupling with UARS-CPE, which was accomplished at room temperature rapidly by the effect of ultrasound and revulsant/synergic reagent. The instrumental conditions and influencing factors relevant to UARS-CPE efficiency, such as concentrations of surfactant and chelating agent, volume of revulsant/synergic reagent, pH, and ultrasound extraction time were studied systematically. The coupling improved the analytical performance of the portable spectrometer considerably. Under the optimal conditions, the limit of detection (LOD) for cobalt was 0.30μg/L, with sensitivity enhancement factor (EF) of 52. In order to validate its application in field analysis, some environmental water samples were field-analyzed with satisfactory results. The established method could be expanded to pre-concentrate and detect many other trace metal ions.

Evaluated the adverse effects of cadmium and aluminum via drinking water to kidney disease patients: Application of a novel solid phase microextraction method.

In present study aluminum (Al) and cadmium (Cd) were determined in ground water samples and assesses human health risks associated with elevated concentrations of toxic metals in dissolved form, using a novel solid phase microextraction (SPμE). Ground water sample (n=200) and biological sample (blood) of patients having chronic kidney disorders (CKD) along with healthy control subjects of same area (southern part of Pakistan) were collected. A simple system, including the micropipette tip packed with modified ionic liquid-activated carbon cloth (IL-ACC) coated with 8-hydroxyqunilone (8-HQ) attached to syringe. The analytes in water and acid digested blood samples were manually drawn for 2-10 cycles (drawing/discharging) at different pH range. The analytes sorbed on coated ACC were then desorbed with 2.0molL(-1) HNO3 in ethanol by drawing/discharging cycles for 1-5 times. The concentration of extracted analytes was determined by electrothermal atomic absorption spectrometer. The influence of different variables on the extraction efficiency of Cd and Al, were optimized. The Al and Cd concentrations in groundwater were found to be elevated than recommended limits by the World Health Organization. The urinary N-acetyl-h-glucosaminidase values were significantly higher in CKD patients as compared to refrent subjects (p<0.001). The significant variation in levels of Cd and Al were observed in blood samples of CKD patients than referents subjects (p<0.01). The strong positive correlation among Al and Cd levels in groundwater versus blood samples of CKD patients (r=0.82-0.85) p<0.01) was observed than those values calculated for referent subjects (r=0.425-0.536).

Development of an on-line solid phase extraction method based on new functionalized magnetic nanoparticles. Use in the determination of mercury in biological and sea-water samples

A new chelating sorbent which employs magnetic nanoparticles (MNPs) functionalized with 1,5-bis(di-2-pyridil)methylene thiocarbohydrazide (DPTH-MNPs) was synthetized and characterized. The aim of the synthesis of this material was to develop fast and simple methods for analysis of trace amounts of metal ions present in biological and environmental samples combining on-line magnetic solid phase microextraction (MSPME) with atomic spectrometry. The MNPs’ magnetic core allows overcoming the backpressure problems that usually happen in SPME methods with NPs thanks to the possibility of immobilizing the MNPs by applying an external magnetic field. Thus, a flow injection FI-MSPME/cold vapor generation system coupled to an electrothermal atomic absorption spectrometer (CV-ETAAS) method for the determination of trace amounts of Hg in biological and sea-water samples was developed. A magnet based reactor designed to contain DPTH-MNPs was placed in the injection valve of the FI manifold. Several chemical and flow variables were considered as factors in the optimization process using central composite designs. With the optimized procedure, the detection limit obtained was 7.8ngL−1 with a precision of 1.7% (RSD) (1.0μgL−1 Hg). The linear range of the method was studied, and two sections of linear calibration were obtained: from determination limit (0.099µgL−1) to 10µgL−1, and from 10µgL−1 to at least 50µgL−1. A preconcentration factor of 5.4 was calculated. The accuracy of the proposed method was demonstrated by analyzing three certified reference materials and by determining the analyte content in spiked sea-water samples. The determined values were in good agreement with the certified values and the recoveries for the spiked samples were in the range of 97.0–107.0%.

An automatic stirring-assisted liquid–liquid microextraction system based on lab-in-syringe platform for on-line atomic spectrometric determination of trace metals

A novel simple fully automatic on-line magnetic stirring-assisted liquid–liquid microextraction method, based on the lab-in-syringe (LIS) concept, has been developed as an alternative approach for sample pretreatment and atomic spectrometric assays. The analytical process includes the in-syringe reaction of the metal ion with the chelating reagent, the analyte micro-extraction and the subsequent transportation of the extractant to the detection system for electrothermal atomic absorption spectrometric (ETAAS) quantification. This novel platform has been demonstrated for trace silver determination in various types of water samples. The method is linear from 19 to 450ngL−1 using a small volume of extraction solvent of 120μL. The entire procedure is accomplished within 240s resulting in a sampling frequency of 15h−1. The enhancement factor is 80, while the detection limit and the precision are 5.7ngL−1 and 3.3%, respectively. The developed method was evaluated by analyzing standard reference materials and spiked water samples with satisfactory recoveries.

Solidified floating organic drop microextraction for speciation of Se (IV) and Se (VI) in water samples prior to electrothermal atomic absorption spectrometric detection

A simple and fast solidified floating organic drop microextraction (SFODME) method is suggested for the speciation of Se (IV) and Se (VI) in water samples prior to electrothermal atomic absorption spectrometric (ETAAS) detection. For that purpose, 1-phenylthiosemicarbazide (PTC) was used as chelating agent and undecanol was used as extraction solvent. The pH of solution, extraction solvent volume, amount of ligand, effect of time for complex formation, and effect of possible foreign ions were also evaluated for quantitative and effective extraction of analyte. Under optimized parameters, detection limit (0.19 $\mu $g L$^{-1})$, limit of quantification (0.60 $\mu $g L$^{-1})$, relative standard deviation (4.6%), linear range (0.60-24 $\mu $g L$^{-1})$, relative error (-4.3%), and enrichment factor (53) were calculated, respectively. The accuracy of the SFODME method was confirmed with analysis of reference material (LGC 6010 Hard drinking water). The presented method was applied to water samples.

Chromium speciation in human blood samples based on acetyl cysteine by dispersive liquid–liquid biomicroextraction and in-vitro evaluation of acetyl cysteine/cysteine for decreasing of hexavalent chromium concentration

A rapid and efficient method based on ionic liquid dispersive liquid–liquid biomicroextraction (IL-DLLBME) was used for speciation and preconcentration of Chromium (III, VI) in human blood samples before determination by electro-thermal atomic absorption spectrometer (ET-AAS). In this method, 1-hexyl-3-methylimidazolium hexafluorophosphate as a ionic liquid was dissolved in acetone as a dispersant solvent and then the binary solution was rapidly injected by a syringe into the blood samples containing CrIII, which have already complexed by acetyl cysteine (NAC) at optimized pH. Under the optimal conditions, the linear range (LR), limit of detection (LOD) and preconcentration factor (PF) were obtained 0.03–4.4μgL−1, 0.005μgL−1 and 10 respectively (RSD <5%). In vitro study show us, the cysteine (Cys) as a prodrug of NAC can decrease the concentration of Cr(VI) in blood samples and human body. Validation of methodology was confirmed by standard reference material (SRM).

Combination of knotted reactor with portable tungsten coil electrothermal atomic absorption spectrometer for on-line determination of trace cadmium

In this work, flow injection (FI) on-line precipitation–dissolution in a knotted reactor (KR) was established and combined with a portable tungsten coil electrothermal atomic absorption spectrometer (W-coil ET-AAS) firstly for preconcentration and determination of ultra-trace cadmium. As a new instrument, the application of the portable W-coil spectrometer was expanded to carry out on-line preconcentration and detection through the coupling with a KR system. A self-assembled FI system was employed to hyphenate the KR system with W-coil ET-AAS. The instrumental conditions and influencing factors relevant to KR efficiency, such as concentration of ammonia, pH, conditions of sampling and elution were studied systematically. The coupling improved the analytical performance of the portable spectrometer considerably. Under the optimal conditions, the limit of detection (LOD) for cadmium was 0.006μg/L, with sensitivity enhancement factor (EF) of 41. The established method could be expanded and used for on-line preconcentration and detection of some other trace metal ions.

In vitro percutaneous penetration and characterization of silver from silver-containing textiles.

The objective of this study was to determine the in vitro percutaneous penetration of silver and characterize the silver species released from textiles in different layers of full thickness human skin. For this purpose, two different wound dressings and a garment soaked in artificial sweat were placed in the donor compartments of Franz cells for 24 hours. The concentration of silver in the donor phase and in the skin was determined by an electrothermal atomic absorption spectrometer (ET-AAS) and by inductively coupled plasma mass spectrometer (ICP-MS). The characterization of silver species in the textiles and in the skin layers was made by scanning electron microscopy with integrated energy dispersive X-ray spectroscopy (SEM-EDX). Additionally, the size distribution of silver nanoparticles in the textiles was performed by atomic force microscopy (AFM). On the surface of all investigated materials, silver nanoparticles of different size and morphology were found. Released silver concentrations in the soaking solutions (ie, exposure concentration) ranged from 0.7 to 4.7 μg/mL (0.6–4.0 μg/cm2), fitting the bactericidal range. Silver and silver chloride aggregates at sizes of up to 1 μm were identified both in the epidermis and dermis. The large size of these particles suggests that the aggregation occurred in the skin. The formation of these aggregates likely slowed down the systemic absorption of silver. Conversely, these aggregates may form a reservoir enabling prolonged release of silver ions, which might lead to local effects.

Determination of sulphur in various vegetables by solid sampling high-resolution electrothermal molecular absorption spectrometry

Sulphur was determined in various vegetables via molecular absorption of carbon monosulphide (CS) at 258.056nm using a solid sampling high resolution continuum source electrothermal atomic absorption spectrometer (SS HR-CS ETAAS). Samples were dried, ground and directly introduced into the ruthenium coated graphite furnace as 0.05 to 0.50mg. All determinations were performed using palladium+citric acid modifier and applying a pyrolysis temperature of 1000°C and a volatilisation temperature of 2400°C. The results were in good agreement with certified sulphur concentrations of various vegetal CRM samples applying linear calibration technique prepared from thioacetamide. The limit of detection and characteristic mass of the method were 7.5 and 8.7ng of S, respectively. The concentrations of S in various spinach, leek, lettuce, radish, Brussels sprouts, zucchini and chard samples were determined. It was showed that distribution of sulphur in CRM and grinded food samples were homogeneous even in micro-scale.