SRM 1566b Research Articles

Experimental designoptimisation and validation by accuracy profile of a novel method for Hg speciation analysis by HPLC-ICP-MS and application to Total Diet Studies.

This study addresses the development and validation of an analytical method for speciation analysis of mercury (inorganic/Hg2+ and methylmercury/CH3Hg+) in fishery products. The Hg species are separated by reversed-phase (RP) high-performance liquid chromatography (HPLC) coupled to inductively coupled plasma mass spectrometry (ICP-MS). The effective separation of Hg2+ and CH3Hg+ was achieved in <8min using a peptide mapping RP column and a mobile phase containing 2-mercaptoethanol at 0.25% (v/v) and methanol at 1%(v/v). The optimization was carried out using an experimental design through response surface methodology (RSM) with central composite design (CCD), addressing both the HPLC separation and the sample extraction. The method validation was carried out based on the accuracy profile approach. For this purpose, six series of measurements were carried out in duplicate over a time span of 2 months. The limits of quantification (LOQ) were 2.5µg/kg (wet weight, ww) for CH3Hg+ and 1.2µg/kg (ww) for Hg2+. The intermediate reproducibility in terms of coefficient of variation (CVR) was <6%. The bias (%) obtained for the analysis of four certified reference materials (CRMs), namely TORT-3 (lobster hepatopancreas), SRM 1566-b (oyster tissue), SQID-1 (cuttlefish) and NMIJCRM7402-a (cod fish tissue) was <7%. This demonstrates the method robustness and suitability for routine speciation analysis of CH3Hg+ and Hg2+ in fishery products. The method is intended to be applied for the analysis of the panel of fishery products and fish-based foods in the framework of the (ongoing) third French Total Diet Study.

Analysis of seven micronutrients in breast milk of lactating mothers from the Central Region of Ghana using epithermal neutron activation

Background: Breast milk contains various micronutrients which nourishes a baby with nutrition, and therefore the endorsement for exclusive breastfeeding during the first six months after birth. Such micronutrients, if in excess, can have adverse effects on the baby.&#x0D; Objective: The levels of seven micronutrients in breast milk obtained from 27 lactating mothers in the Cape Coast Metropolitan area have been determined using Epithermal Neutron Activation Analysis (ENAA). This technique was used because it is suitable for performing both qualitative and quantitative multi-nutritional analyses on samples, and offers accuracies and sensitivities superior to those attainable by other methods.&#x0D; Materials and Methods: During the analysis, a- 3 mm thick flexible boron was used to cut-off thermal neutrons so as to assess epithermal neutrons, thereby creating an activation energy which measured the levels of micronutrients in the breast milk. The standard reference materials used were the International Atomic Energy Agency (IAEA)-336; IAEA-407, IAEA-350 and National Institute of Standard and Technology (NIST) USA SRM 1577b. The Relative standardization method was used in the quantification of the micronutrients, with an accuracy of about 94.7 %. The micronutrients are Sodium (Na), Magnesium (Mg), Potassium (K), Calcium (Ca), Manganese (Mn), Copper (Cu) and Iodine (I).&#x0D; Results: Except for iodine which had levels below the recommended dietary allowance (RDA), the remaining micronutrients had levels above the upper limit of the RDA, with Manganese being the highest.&#x0D; Conclusion: The levels recorded are directly linked to the food intake of the mothers, and therefore the need for pregnant and lactating mothers to be mindful about what they eat. Children could be exposed to metabolic disorders and diseases as a result of such high levels.

Psittaciformes mineral feed analysis method choice and optimization employing chemometric tools

BackgroundIn this work, a multivariated approach based on factorial design and principal component analysis was used to perform the optimization of sample decomposition. The method was applied for the first time to quantify several chemical elements (Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, P, Pb, Se and Zn) in Psittaciformes feed. The choice of the best sample decomposition method is a challenging task considering all variables involved in the process. Generally, this choice is made by using individual monovariated experiments and sometimes interaction effects between these variables as mass of the sample, acid composition, temperature, etc, are not considered. MethodsSample decomposition: 200 mg of sample was mixed with 3.5 mL of HNO3 65% and left at room temperature for 24 h, in a pre-decomposition step, heated at 150 °C for 50 minutes employing a digestion block and mixed with 1.5 mL of H2O2 in the last ten minutes of decomposition. Chemical analysis: A total of 44 samples of Psittaciformes feed digests, among extruded feed, flour and snacks), purchased at pet stores or similar stores in six states in Brazil, were analyzed by inductively coupled plasma optical emission spectrometry (ICP OES). Method accuracy was assessed using certified reference materials SRM 1567a, SRM 1573a, SRM 1577b and IMEP 19. ResultsThe limits of detection (LoD) and quantification (LoQ) ranged from 0.02 mg kg−1 to 0.07 mg kg−1 (Se) and from 1.79 mg kg−1 to 5.41 mg.kg−1 (Ca), respectively. The concentration of chemical elements in animal food ranged from <0.27 mgkg −1 (Fe) to 41.4 ± 2.9 g kg−1 (P), in flour concentrations ranged from <0.05 mg kg−1 (Mg) to 23.8 ± 4.1 g kg−1 (P) and concentrations ranged from <0.05 mg kg−1 (Mn) to 6.8 ± 0.9 g kg−1 (Ca) in snacks. ConclusionThe approach based on multivariate analysis to perform a sample decomposition was successfully applied for Psittaciformes feed. In general, the chemical elements listed on the product labels (Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, P, Pb, Se and Zn) were detected at variable contents when compared to the recommender nutritional values. Toxic elements, Cd and Pb were not detected in any of the analyzed samples. The detection and quantification of chemical elements not listed in nutritional tables and in each product label indicates that mineral addition by manufacturers is performed without considering the chemical composition of the raw materials used in the production process, which can lead to nutritional issues. Thus, a broad revision of Brazilian Legislation concerning product classification considering quality and mineral addition criteria in daily animal feed, especially pets, is urgently required.

Development of method for determination and preconcentration of uranium in water samples using XAD-4 resin loaded with Br-PADAP

In the present work, a minicolumn of XAD-4 loaded with 2-(5-bromo-2-pyridylazo)-5-(diethylamino)-phenol (Br-PADAP) is proposed as a preconcentration system for uranium determination in well, tap and mineral water samples by spectrophotometer using arsenazo III as the chromogenic reagent. Initially, a two-level (23) full factorial design was used for the preliminary evaluation of three factors, involving the following variables: sampling flow rate, elution flow rate, and pH. This design has revealed that, for the studied levels, buffer concentration and pH were significant factors. When the experimental conditions established in the optimization step were pH = 8.6, and an elution flow rate of 8.6 mL min−1 using 0.5% m/v ascorbic acid, this system has allowed for the determination of uranium with a detection limit (LOD) (3σ/S) of 0.05 μg L−1 and a quantification limit (LOQ) (10σ/S) of 0.16 μg L−1. The precision expressed as the relative standard deviation (R.S.D.) of 0.8% and 1.9% at 10.0 and 1.0 μg L−1, respectively- and a preconcentration factor of 184.5 for a sample volume of 50.0 mL. Accuracy was confirmed by uranium determination in the standard reference material, NIST SRM 1566b trace element units in Oyster Tissue samples, and spike tests with recuperations ranging from 93.2 to 105%; the procedure were applied for uranium determination in tap water, well water, and drinking water samples collected from Caetité and Cruz das Almas Cities, Bahia, Brazil. Five water samples were analyzed the uranium concentrations varied from 0.50 to 2.07 μg L−1

Preconcentration of mercury(II) using a magnetite@carbon/dithizone nanocomposite, and its quantification by anodic stripping voltammetry.

A new adsorbent is described that consists of a magnetite@carbon/dithizone nanocomposite. It was characterized using energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and field emission scanning electron microscopy. The magnetic sorbent is shown to be a viable material for the preconcentration of mercury(II) before its quantification by differential pulse anodic stripping voltammetry. The effects of pH value, eluent, adsorbent amount, sample volume, and adsorption/desorption time were optimized. The calibration plot extends from 0.25 to 30ng.mL-1, and the detection limit is 27pg.mL-1. The preconcentration factor and intra-day and inter-day relative standard deviations are 100, 3.8, and 4.5%, respectively, for six measurements at 5ng.mL-1 concentrations of mercury(II). The method was validated by the analysis of the certified reference material NIST SRM 1566b, and successfully applied to the preconcentration and quantification of mercury(II) in industrial wastewaters and spiked water samples. Graphical abstractSchematic representation of magnetic solid-phase extraction of mercury(II) ion by dithizone-modified Fe3O4@C nanocomposite (Fe3O4@C/Dz NC) before its quantification by anodic stripping voltammetry (ASV).

Preparation and evaluation of a new reference material for macro- and micronutrients in fish feed

A new reference material for inorganic constituents analysis in fish feed was produced and characterized according to the ISO Guides 30-35. The evaluation of the estimated minimum mass, homogeneity, and short- and long-term stability of the material was performed using microwave-assisted digestion and inductively coupled plasma optical emission spectroscopy as an in-house validated technique for Ca, Cu, Fe, K, Mg, Mn, Na, P, and Zn analysis. The accuracy of the measurements results was confirmed by analyzing the certified reference materials Oyster Tissue and Tomato Leaves, NIST SRM 1566b and SRM 1573a. The chemical characterization concerning elemental composition was performed through a collaborative trial with the participation of 35 laboratories by using spectroscopic and instrumental neutron activation analysis techniques. One-way analysis of variance (ANOVA) and regression analysis were the statistical methods applied to achieve the consensus values and their combined uncertainty, and the homogeneity and stability of the material presented averages within the 95% confidence interval. The expanded uncertainty considered all the instability observed during the stability, homogeneity, and characterization tests. The certified values and expanded uncertainties (k = 2) for the candidate reference were (28.65 ± 1.84) g kg−1 Ca, (10.51 ± 0.87) mg kg−1 Cu, (231.97 ± 20.17) mg kg−1 Fe, (5.86 ± 0.31) mg kg−1 K, (1.55 ± 0.16) g kg−1 Mg, (19.46 ± 2.12) mg kg−1 Mn, (2.16 ± 0.19) g kg−1 Na, (16.06 ± 0.97) g kg−1 P, and (129.56 ± 6.79) mg kg−1 Zn. The produced material proved its suitability for internal instrumental quality control or for the quality assurance of Ca, Cu, Fe, Mg, Mn, Na, P, and Zn analysis in fish feed for evaluation the laboratories quality control.

Development of a portable grazing exit X-ray fluorescence system using a gold anode X-ray tube

A portable grazing exit X-ray fluorescence system (GE-XRF) composed of a low power X-ray tube (gold anode), a SiPIN detector, quartz reflector and an XY table plus rotary stage for positioning the reflector in grazing exit condition was developed in this work. The accuracy of the system was checked using a certified bovine liver sample (SRM 1577b, NIST). The relative errors between measured and certified values ranged from 2 to 22%, except P (39%) and S (26%). The absolute detection limits obtained with the portable system were in the range of 4–300 ng (15 ≤ Z ≤ 30). The portable GE-XRF system developed does not favor the detection of light elements since absorption effects were more critical (sample-to-detector distance ∼ 35 mm). Besides that, it was operated under room temperature and atmospheric pressure, 20 °C and 1.0 atm, respectively. The quantitative results of a multielement reference sample were compared with the results of a GI-XRF system. Both techniques were compatible and presented good accuracy with reference values. The portable GE-XRF system developed in this work was efficient, showing that it is possible to produce a grazing exit X-ray fluorescence system using a low power X-ray tube, a Si-PIN detector and quartz reflector.

Infrared radiation as a heat source in sample preparation of shrimp for trace element analysis

An open sample preparation system based on use of infrared radiation (IR) for heating was used to accelerate the mineralization of shrimp samples to quantify their As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Se, Sn and V content by ICP-OES. The method presented good accuracy, as verified by analysis of NIST SRM 1566b oyster tissue, acceptable precision (<20% RSD) and low RCC in the solutions (<3 % w w−1). Optimal experimental conditions (1.0 g sample, 8 mL of HNO3, 8 min heating with a 500 W of lamp) were obtained using a full factorial design. The method was applied to whole harvested shrimp samples (with head, exoskeleton and viscera), which revealed levels of As (4.84 ± 0.23 mg kg−1) and Cd (0.80 ± 0.01 mg kg−1) above those allowed by Brazilian law. Sample preparation based on IR-assisted digestion provides a quick, simple and inexpensive alternative to conventional sample preparation techniques.

Analysis of milk trace elements with a home-made portable automated total reflection x-ray fluorescence system

This paper presents a portable, high-tech, low-cost, total reflection X-ray fluorescence system. This system features a compact arrangement consisting of a 50 W X-ray mini-tube with a Mo anode and a Si-PIN detector, quartz reflectors, lucite monochromator and micrometric tables driven by step motors controlled through the Arduino programming software. A certified sample of bovine liver SRM 1577b by NIST was used for the validation of the portable automated TXRF system. The TXRF system was used in the analysis of bovine milk samples collected in the industrialized region of the city of Bauru, São Paulo. In the analysis of the bovine milk samples the following elements were detected: P, S, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Se, Rb and Sr. The TXRF portable automated system proved to be efficient, showing that it is possible to produce X-ray fluorescence with a low-cost system using a low-power X-ray tube and a compact Si-PIN detector.

Speciation of mercury in water and freshwater fish samples by a two-step solidified floating organic drop microextraction with electrothermal atomic absorption spectrometry.

A new and simple two-step SFODME using 4-nitro-o-phenylenediamine (4-NOPD) as a chelating agent was developed for mercury speciation in water and fish samples by ETAAS. For the first step, methylmercury was extracted into 1-undecanol and for the second step, the Hg(II) remaining in the sample solution was complexed with 4-NOPD and then extracted into 1-undecanol. Under the optimized conditions, the calibration graphs of Hg(II) and methylmercury were linear in the range of 0.83-8.0 µg L-1 and 0.78-8.0 µg L-1, with the LOD of 0.25 µg L-1 and 0.24 µg L-1 and the enrichment factor were 25.7 and 32.2, respectively. The %RSDs was in the range of 2.0-4.4% at concentrations of 0.5 and 4.0 µg L-1 (n = 5). The proposed method was successfully applied to mercury speciation in water and fish samples. The accuracy of method, tested by the analysis of SRM 1566b and DORM-4 was in good agreement with the certified values.

Preconcentration of Pb(II) by using Mg(II)-doped NiFe2O4 nanoparticles as a magnetic solid phase extraction agent.

Magnesium(II)-doped nickel ferrite (Mg-NiFe2O4) nanoparticles are introduced as a new adsorbent for magnetic solid phase extraction of lead(II) ions from aqueous solutions. The structure and morphology of the adsorbent was characterized by FTIR, X-ray diffraction and scanning electron microscopy. The effects of pH value, amount of adsorbent, type, concentration and volume of the eluent and adsorption/desorption time on the extraction efficiency were studied. Following elution with hydrochloric acid, Pb(II) ions were quantified by flame atomic absorption spectrometry. Under optimized conditions, the calibration graph is linear in the 0.5-125ngmL-1 Pb(II) ion concentration range. Other figures of merit include (a) a 0.2ngmL-1 limit of detection, (b) an enrichment factor of 200, (c) an intra-day relative standard deviation (for n= 6 at 50ngmL-1) of 1.6%, and (d) an inter-day precision of 3.8%. The method was validated by the analysis of the certified reference material, NIST SRM 1566b. It was successfully applied to the determination of Pb(II) ion in spiked water samples, industrial wastewater and acidic lead battery waters. Graphical abstract Schematic of the synthesis of Mg(II)-doped NiFeO4 nanoparticles and their application as a magnetic sorbent for solid-phase extraction of a Pb(II) ions prior to determination by flame atomic absorption spectrometry (FAAS).

Vortex-Assisted Solidified Floating Organic Drop Microextraction of Molybdenum in Beverages and Food Samples Coupled with Graphite Furnace Atomic Absorption Spectrometry

A simple, rapid, sensitive, and selective vortex-assisted solidified floating organic drop microextraction (VA-SFODME) method was developed for the determination of molybdenum in beverages and food samples by using graphite furnace atomic absorption spectrometry (GFAAS). 4-Amino-3-hydroxy-1-naphthalenesulfonic acid (AHNA) was used as complexing reagent. 1-Undecanol was used as extraction solvent. Analytical parameters were investigated and optimized as pH 5, ligand amount 1 mg, volume of 1-undecanol 100 μL, extraction time 4 min, and sample volume 20 mL. Under optimum conditions, enrichment factor (EF) and limit of detection (LOD) for Mo(VI) were found to be 133 and 10 ng L−1, respectively. The relative standard deviation (RSD) was found to be 2.5 %. Matrix effects of some cations, anions, and transition metal ions were also investigated. The accuracy of the VA-SFODME method was confirmed by the analysis of certified reference materials (NIST SRM 1568a rice flour, GBW 07605 tea, and NIST SRM 1577b bovine liver). Optimized method was successfully applied to beverages and food samples after microwave digestion method.

Assessment of essential elements and chemical contaminants in thirteen fish species from the Bay Aratu, Bahia, Brasil.

Concentrations of ten elements (Cd, Cr, Cu, Fe, Ni, Pb, Se, Sr, V and Zn) were determinate in muscle tissues of 13 fish species from Aratu Bay, Bahia, Brazil by inductively coupled plasma optical emission spectrometry. The accuracy and precision of our results were checked by using two certified reference materials: BCR-422 cod muscle and SRM 1566b oyster tissue. The average trace element concentrations in the fish species varied in the following ranges, in μg g-1: 0.03-0.8 for Cr; 2.0-33.7 for Cu, 2.4-135.1 for Fe, 1.6-25.6 for Se; 1.6-35.1 for Sr; and 2.8-40.5 for Zn. The Diaptereus rhombeus (carapeba) specie presented the highest concentrations of Se, Cu and Fe. Chromium and Se were present at levels above the limit of tolerance allowed by the National Agency of Sanitary Vigilance (ANVISA). The results were also evaluated using the multivariate analysis techniques: principal component analysis (PCA) and hierarchical cluster analysis (HCA).

A novel chemosensor based on graphitic carbon nitride quantum dots and potassium ferricyanide chemiluminescence system for Hg(II) ion detection

In this research, graphitic carbon nitride quantum dots (g-CNQDs) were prepared by a simple and one-step microwave-assisted approach and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The chemiluminescence (CL) emission of the synthesized g-CNQDs induced by K3Fe(CN)6 as an oxidant along with the CL mechanism were investigated. Based on the diminishing effect of Hg(II) ion on the g-CNQDs–K3Fe(CN)6 CL system, a simple and sensitive chemosensor was constructed for Hg(II) ion detection in aqueous solutions. A response surface methodology was used to optimize the experimental parameters affecting the analytical signal. Under the optimized experimental conditions, the calibration graph was linear in the range of 0.25–10ngmL−1 with a detection limit of 0.08ngmL–1. The inter-day and intra-day relative standard deviations for six replicate determinations of 4ngmL–1 Hg(II) ion were 3.4% and 2.8%, respectively. The developed method was successfully applied for the selective and sensitive determination of Hg(II) in water and food samples with recoveries in the range of 95.7–102.8% for the spiked samples. The accuracy of the method was evaluated by analyzing a certified reference material (SRM 1566b).

On-line UV photochemical generation of volatile copper species and its analytical application

Volatile Cu species were on-line generated by photochemical reduction in a formic acid medium utilizing a unique flow-through photochemical reactor. Digests of biological samples in 18% formic were introduced to the photochemical vapor generation (PVG) reactor under conditions wherein copper-containing species were initially retained on the reactor wall following a purge of the line with air and desorbed in the presence of a plug of 60% formic acid to yield volatile species which were transported to a gas–liquid separator and introduced to multi-collector inductively coupled plasma spectrometry (MC-ICPMS). Sensitivity of the proposed method could be further improved if a sample solution is repeatedly introduced using several cycles comprising loading and drying steps. However, the unstable volatile Cu species generated by PVG together with the early release of Cu during drying step resulted in a poor measurement precision of near 30% (n=4, RSD) and a non-linear correlation between the signal intensity and the Cu2+ concentration. Despite the above shortcomings, the accurate and precise determination of Cu concentrations in biological samples was achieved by applying isotope dilution (ID) calibration. A method detection limit of 8ngg−1 normalized to a nominal test mass of 0.25g of sample was obtained based on ID quantification. Method validation was demonstrated by analysis of three biological certified reference materials of TORT-3, SRM 1566b and DOLT-5 with satisfying results. Concentrations of 490.8±0.6, 71.88±0.06 and 34.95±0.04μgg−1 (1SD, n=4) with precisions of 0.12, 0.08 and 0.13% RSD for Cu were obtained in TORT-3, SRM 1566b and DOLT-5, respectively, in good agreement with certified values.

Silica-coated Mn3O4 nanoparticles coated with an ionic liquid for use in solid phase extraction of silver(I) ions prior to their determination by AAS

We demonstrate the applicability of ionic liquid-modified silica-coated Mn3O4 nanoparticles (NPs) as a sorbent for solid-phase extraction and preconcentration of Ag(I) ion without a chelating agent. The size, morphology and surface coating of the nano-sorbent were characterized via X-ray diffraction analysis, scanning electron microscopy and Fourier transform IR spectroscopy. Following desorption with HCl, silver was quantified by AAS. Under optimized experimental conditions, the calibration graph is linear in the 0.8 − 320 ng mL−1 concentration range (with an r2 of 0.9970). The limit of detection and limit of quantification are 0.2 and 0.8 ng mL−1, respectively. The relative standard deviation (for n = 6; at an Ag(I) concentration of 60 ng mL−1) and preconcentration factor are 1.9 % and 50, respectively. The method was used to determine Ag(I) in (spiked) water samples and in radiology films. The accuracy of the method was confirmed by successfully analyzing the certified reference material NIST SRM 1566b.

Determination of Total Mercury in Sushi Samples Employing Direct Mercury Analyzer

In this study a simple, fast, and low-chemical- consuming method was evaluated for the determination of total mercury in sushi samples by thermal decomposition amalgamation atomic absorption spectrometry (TDA- AAS) using a direct mercury analyzer (DMA). A small portion of fresh sushi sample (60 mg) is combusted in nickel or quartz containers, and the released mercury is trapped in a gold amalgamator, being desorbed at high temperatures and measured in an atomic absorption cell. The method accuracy was evaluated using certified refer- ence materials (CRM) rice flour (NIST SRM 1568b), fish protein (NRC DORM-4), peach leaves (NIST SRM 1547), and oyster tissue (NIST SRM 1566b), and the method accuracy varied between 94 and 112 % for all the CRM. Analytical curves were prepared using 0.5 % nitric acid solutions (v/v )f or low (0.5 to 50μ gk g �1 )a nd high concentrations (100 to 1000 μ gk g �1 )a nd the corre- lation coefficients were above 0.999. The detection and quantification limits were 0.4 and 1.4 μ gk g �1 , respective- ly. The method was applied to 30 sushi samples of tuna, salmon, and kani from Campinas City, Sao Paulo State, Brazil, and the results ranged from 6.2 to 761, 1.5 to 4.0, and <1.4 to 13.5μ gk g �1 , respectively. High amounts of

Determination of Lead, Copper, and Iron in Cosmetics, Water, Soil, and Food Using Polyhydroxybutyrate-B-polydimethyl Siloxane Preconcentration and Flame Atomic Absorption Spectrometry

A separation and preconcentration method has been established based on solid phase extraction of Fe(III), Cu(II) and Pb(II) as their 2-(5-Bromo-2-pyridylazo)-5-diethylamino-phenol (5-Br-PADAP) chelates adsorbed on polyhydroxybutyrate-b-polydimethyl siloxane. Several analytical conditions including pH, amount of (5-Br-PADAP), eluent type and volume, sample volume, and flow rates were investigated. The effects of foreign ions on the recovery of the analytes were also studied. The detection limits for Cu(II), Fe(III), and Pb(II) were 1.9, 2.2, and 2.5 µg per liter, respectively. Enrichment factors for Cu(II), Fe(III), and Pb(II) were 150, 200, and 80, respectively. The adsorption capacity of the polymer for Cu(II) and Pb(II) studied was 10.2 and 17.2 milligrams per gram respectively. Relative standard deviation was 4%. Standard Reference Material (SRM 1577B Bovine liver), International Atomic Energy Agency (IAEA 336 Lichen), and Certified Reference Waters for Trace Elements (TMDA 51.3 Fortified lake water) were used for the validation of the method. Optimized procedure was applied for the determination of analyte elements in various cosmetic products, hair brilliantine and gel, water, soil, and food samples from Turkey.

Ultrasound assisted-deep eutectic solvent extraction of iron from sheep, bovine and chicken liver samples

A green, novel and effective ultrasound assisted-deep eutectic solvent (DES) extraction (UA-DES-E) procedure was developed for extraction of iron from sheep, bovine and chicken liver samples. The analytical parameters including type and composition DES, volume of DES, ultrasonication time and ratio of sample to DES were optimized by using 50mg of the NIST SRM 1577b bovine liver certified reference material. The limit of detection (LOD) and the limit of quantification (LOQ) were found as 0.026µgmL−1 and 0.085µgmL−1, respectively. The relative standard deviation (RSD) as a result of 7 replicates of 50mg of certified reference material was 1.4%. The accuracy of proposed method was checked by the addition/recovery tests to NIST SRM 1577b bovine liver and a sheep liver. The extraction method was applied to extraction of iron from bovine, sheep and chicken liver samples retail from markets at Kayseri, Turkey with satisfactory results (recoveries higher than 95%).

Development and characterization of a portable total reflection X-ray fluorescence system using a waveguide for trace elements analysis.

This paper presents a portable total reflection X-ray fluorescence system composed of a 15 W X-ray tube, with a gold anode, a waveguide constituted by two Perspex(®) parallel plates, a Si PIN detector and a quartz optical flat. The critical angle of the total reflection system was experimentally determined by measuring a zinc solution (100 mg/L). The accuracy of the system was checked using SRM 1577b Bovine Liver by NIST as standard reference material. We obtained the absolute detection limits of the following elements: P (450 ± 40 ng), S (200 ± 31 ng), K (30 ± 2.5 ng), Ca (19 ± 3.5 ng), Mn (4.1 ± 0.5 ng), Fe (3.6 ± 0.9 ng), Cu (3.3 ± 0.4 ng) and Zn (3.5 ± 0.3 ng). This paper shows that it is possible to produce total reflection X-ray fluorescence with very compact, efficient, low-cost and easy-to-handle instrumentation using a low-power X-ray tube and a Si PIN compact detector.