Nickel In Environmental Samples Research Articles

An eco-friendly ultrasound-assisted deep eutectic solvent-based liquid–phase microextraction method for enrichment and quantification of nickel in environmental samples

An eco-friendly and easy ultrasound-assisted liquid phase microextraction approach using deep eutectic solvent (UA-DES-LPME) was established to preconcentrate and separate trace amount of nickel (Ni(II)) in various environmental samples before flame atomic absorption spectrometric estimation. In this method, Ni(II) was complexed with 2-(benzothiazolyl azo) orcinol reagent. The impacts various parameters on the microextarction of Ni(II) was investigated. The calibration graph is linear in the range of 1–500 µg L−1 and limits of detection and quantification were determined as 0.27 and 0.90 μg L−1, respectively. The RSD% and preconcentration factor were 2.30% and 100, respectively. The analysis of certified reference materials demonstrated the validity of the established procedure. The microextraction method provided here simple, rapid, cheap, green and was effectively used to determine nickel levels in a variety of environmental samples with recoveries ranged of 95.0–98.54%.

Development a simple and sensitive method for determination low trace of nickel by local surface plasmon resonance of citrate capped silver nanoparticles

Nickel is a toxic transition metal which can create serious problems in health of humans and wildlife. Thus determination of nickel in environmental samples like waters is important and inevitable. In this research a simple and sensitive method for determination of nickel in water was described based on aggregation of citrate capped silver nanoparticles. Silver nanoparticles were prepared by reduction of silver nitrate with sodium borohydride. Cefixime was as chelating agent in the assay and when nickel was added to the mixture of citrate capped silver nanoparticles and cefixime, color of citrate capped silver nanoparticles changed from light yellow to red that depend on Ni2+ concentration. As a result of aggregation, local surface plasmon resonance (LSPR) band of silver nanoparticles around 395 nm decreased and a new peak appeared in 550 nm. Control experiments with 10 other ions carried out and did not a distinct change in color or spectrum. Under optimized conditions, linear relationship between Ni2+ concentrations and the absorbance ratio of A550/A395 and limit of detection were found in the range of 2.70 µmol L-1 to 17.10 µmol L-1 and 0.80 µmol L-1, respectively. The method was applied in tap and well waters that indicate the colorimetric method has acceptable accuracy and good stability.

Solid-Phase Extraction and Detection by Digital Image Directly in the Sorbent: Determination of Nickel in Environmental Samples

Recently, analytical procedures based on computer vision related to the colorimetric analysis of digital images have been described in the scientific literature. In this sense, a novel analytical approach is presented based on digital image colorimetry for nickel determination. The method consists in the development of a system with solid-phase extraction, consisting basically of an extraction chamber filled with polystyrene divinylbenzene sorbent impregnated with the complexing reagent 1-(2-thiazolylazo)-p-cresol (TAC) and a portable microscope multifunction, used for image acquisition. The image of the sorbent after extraction of Ni is obtained. This image is related to the concentration of the elements. The variables (pH, flow, and sample volume) were evaluated using a full factorial design 23 for the screening and a Doehlert matrix to establish the significant variables’ optimal levels. The enrichment factor and limit of detection were 148 and 0.8 μg L−1, respectively. The method was applied to the determination of nickel in river water, coffee, and cigarette samples.

Surface active ionic liquid‑assisted cloud point extraction method for preconcentration of nickel in environmental samples before its FAAS determination

Green, rapid and modified surface-active ionic liquid assisted cloud point extraction method (SAIL-CPE) was developed to preconcentrate trace levels of nickel Ni(II) ions in environmental samples perior to its detection by FAAS. The proposed method based on utilizing a mixture of a nonionic surfactant (Triton X-114) and a surface-active ionic liquid, 1-hexadecyl-3-methylimidazolium chloride (C16MeImCl), as an extracting phase for Ni(II) ions after the complexation with sunset yellow FCF at pH 6.5. The impact of different analytical parameters on improving the extraction efficiency was invistigated. In the range of 2.0-600 µg L−1, the calibration graph was linear with correlation coefficient of 0.9998. Limit of detection and preconcentration factor were 0.6 and 100. The reliability and precision of the proposed SAIL-CPE system as the relative standard deviation (RSD %) in the presence and absence of SAIL were examined by applying ten replicate determinations of 300 µg L-1 of Ni(II), and RSD % of the recoveries were found to be 1.40 and 2.9%, respectively. The validation of the proposed procedure was verified by test of certified reference materials (TMDA-51.3 fortified water, TMDA-53.3 fortified water and SRM spinach leaves 1570A) applying the standard addition method. Finally, the proposed SAIL-CPE method was developed and applied to preconcentrate and determine of trace levels of Ni(II) ions in real water, food and tobacco samples with satisfactory results.

Mesoporous Silica Nanoparticles as an Adsorbent for Preconcentration and Determination of Trace Amount of Nickel in Environmental Samples by Atom Trap Flame Atomic Absorption Spectrometry

A rapid enrichment method based on solid-phase extraction (SPE) has been established for preconcentration and separation of trace Ni(II) ions in water samples prior to their determination by atom trap flame atomic absorption spectrometry. A column filled with bulky NH2–UVM7 was used as the novel adsorbent. Under optimal conditions, the linear range, limit of detection (LOD), and preconcentration factor (PF) were 3–92 μg/L, 0.8 μg/L, and 100, respectively. The validity of the method was checked by the standard reference material.

High capacity polymer for nickel determination in environmental samples

High AA new high capacity sorbent for preconcentration and determination of nickel in environmental samples was synthesized. The sorbent was synthesized by copolymerization of allyl glaycidyl ether / imminodiacetic acid with N,N-dimethylacrylamide as functional monomers in the presence of N,N-bismethylenacryl amid as cross linker and characterized by Fourier transform infra red spectroscopy, elemental analysis, thermogravimetric analysis and scanning electron microscopy. A recovery of 93.6% was obtained for the metal ion with 0.1 M, sulfuric acid as the eluting agent. The sorption capacity of the functionalized sorbent was 55.9 <TEX>$mgg^{-1}$</TEX>. The equilibrium sorption data of Ni(II) on polymeric sorbent were analyzed using Langmuir, Freundlich, Temkin and Redlich.Peterson models. Based on equilibrium adsorption data the Langmuir, Freundlich and Temkin constants were determined 0.87 (L mg-1), 25.87 (<TEX>$mgg^{-1}$</TEX>) <TEX>$(Lmg^{-1})^{1/n}$</TEX> and 171.4 (<TEX>$Jmol^{-1}$</TEX>) respectively at pH 4.5 and <TEX>$20^{\circ}C$</TEX>.

Synergistic enhancement effect of room temperature ionic liquids for cloud point extraction combined with UV–vis spectrophotometric determination nickel in environmental samples

A new method based on enhancement effect of room temperature ionic liquids for cloud point extraction trace amounts of nickel combined with UV–vis spectrophotometric determination was developed. Room temperature ionic liquids (RTILs) and diethyldithiocarbamate (DDTC) were used enhancement reagent and chelating reagent, respectively. The addition of room temperature ionic liquids leads to 3.0 times improvement in the determination of nickel. The nonionic surfactant Triton X-100 was used as the extractant. When the temperature of the system was higher than the cloud point of Triton X-100, Ni-DTC complex was extracted into Triton X-100 and separation of the analyte from the matrix was achieved. Some parameters that influenced cloud point extraction and subsequent determination were evaluated in detail, such as the concentrations of RTILs, DDTC and Triton X-100; pH of sample solution, as well as interferences. Under optimized conditions, an enrichment factor of 72 could be obtained, and the detection limit (LOD) for Ni was 0.5ngmL−1. Relative standard deviations for five replicate determinations of the standard solution containing 50ngmL−1 Ni was 3.9%. The proposed method was successfully applied to the determination of nickel in certified reference materials with satisfactory results.

Determination of nickel by chemical vapor generation in situ trapping flame AAS

Abstract The analytical performances of coupled chemical vapor generation, integrated atom trap (CVG-IAT) atomizer flame atomic absorption spectrometry (FAAS) system were evaluated for determination of nickel in environmental samples. Nickel chemical vapors are atomized in an air-acetylene flame-heated IAT. A new design of CVG-IAT-FAAS hyphenated technique that would exceed the operational capabilities of existing arrangements (a water-cooled single silica tube, double-slotted quartz tube) permitting construction of an “integrated trap” was investigated. An improvement in limit of detection was achieved compared with that obtained using any of the above atom trapping techniques separately. The concentration limit of detection was 1 ng mL−1 for Ni. The overall efficiencies of the vapor generation process was estimated to be ca. 50%. For a 2 min in situ pre-concentration time, sensitivity enhancement, compared to FAAS, was 200 folds for Ni, using vapor generation atom trapping technique. The sensitivity can be further improved by increasing the collection time. The precision of the measurements for 25 ng mL−1 of Ni was 9% RSD. The accuracy of this method was tested by analyses of NIST SRM 2704 (Buffalo River Sediment), NIST SRM 1648 (Urban Particulate Matter), NIST SRM 2710 (Montana Soil), NBS SRM 1633a (Coal Fly Ash) and NIST SRM 1643e (Trace Element in Water) certified reference materials. The measured Ni content in five reference materials was in satisfactory agreement with the certified values (in the range of 14.3–98 μg g−1). The hyphenated technique was applied for nickel determination in coal fly ash, soil, sediment, sewage and river water.

Enrichment and determination of Ni 2+ ions in water samples with a diamino-4-(4-nitro-phenylazo)-1H-pyrazole (PDANP) by using FAAS

Nickel, as a heavy metal, is toxic for many living species. Thus, the determination of trace amounts of nickel in environmental samples is of great importance. In the present study, new, sensitive, simple and validated solid phase extraction method is developed for the determination of nickel. In recent study nickel was preconcentrated as diamino-4-(4-nitro-phenylazo)- 1H-pyrazole (PDANP) chelates (Ni-PDANP) from sample solutions using a column containing Amberlite XAD-7 and determined by flame atomic absorption spectrometry (FAAS). The optimum experimental parameters such as pH of the medium, sample flow rate, eluent and effect of matrix ions on the method efficiency were investigated. The optimum pH value for quantitative sorption of Ni–PDANP was found between 6.0 and 8.0. Elution process was performed by using 6 mL of 2 mol L − 1 HCl. The sorption capacity of resin was determined to be 7.2 mg g − 1 for Ni. The preconcentration factor was 125. In optimized conditions. A relative standard deviation and detection limit were found to be 2.8% and 0.44 μg L − 1 respectively. The method was successfully applied to determine the trace amounts of nickel in tap water and mineral waters, and suitable recoveries were obtained (100.0–103.5%).

Determination of ultra-trace amounts of nickel in environmental samples by atomic absorption spectrometry with in-situ trapping of volatile species in an iridium–palladium coated graphite furnace

A sensitive and accurate method is described for the determination of ultra-trace nickel in environmental samples with in-situ trapping of volatile species in iridium-palladium coated graphite furnace atomic absorption spectrometry. The effects of the conditions for the generation and collection of volatile nickel species, such as medium acidity, potassium borohydride concentration, enhancement reagent concentration, reaction temperature, as well as graphite tube coating, carrier gas flow rate and trapping time were investigated. Phenanthroline was selected as the enhancement reagent due to its good enhancing effect, and iridium–palladium coating was used for the in-situ trapping of volatile nickel species at 300°C. Under the optimal conditions, the calibration curve was linear from 0.21 up to 30.0 ng mL−1 with correlation coefficient of 0.9991, the detection limit (S/N = 3) was 0.21 ng mL−1 for 4 mL sample volumes and the relative standard deviation for 11 determinations of Ni at 10 ng mL−1 was 3.5%. The results found by the proposed methods are accordant with the certified values of water, soil and tea certified reference materials. The proposed methods have been applied for the determination of ultra-trace Ni in tap, river and wastewater, as well as rice and soil samples, with recoveries ranging from 97.3 to 100.5%.

Determination of lead and nickel in environmental samples by flame atomic absorption spectrometry after column solid-phase extraction on Ambersorb-572 with EDTA

Lead and nickel were preconcentrated as their ethylenediaminetetraacedic acid (EDTA) complexes from aqueous sample solutions using a column containing Ambersorb-572 and determined by flame atomic absorption spectrometry (FAAS). pH values, amount of solid phase, elution solution and flow rate of sample solution have been optimized in order to obtain quantitative recovery of the analytes. The effect of interfering ions on the recovery of the analytes has also been investigated. The recoveries of Pb and Ni under the optimum conditions were 99 ± 2 and 97 ± 3%, respectively, at 95% confidence level. Seventy-five-fold (using 750 mL of sample solution and 10 mL of eluent) and 50-fold (using 500 mL of sample solution and 10 mL of eluent) preconcentration was obtained for Pb and Ni, respectively. Time of analysis is about 4.5 h (for obtaining enrichment factor of 75). By applying these enrichment factors, the analytical detection limits of Pb and Ni were found as 3.65 and 1.42 ng mL −1, respectively. The capacity of the sorbent was found as 0.17 and 0.21 mmol g −1 for Pb and Ni, respectively. The interferences of some cations, such as Mn 2+, Co 2+, Fe 3+, Al 3+, Zn 2+, Cd 2+, Ca 2+, Mg 2+, K + and Na + usually present in water samples were also studied. This procedure was applied to the determination of lead and nickel in parsley, green onion, sea water and waste water samples. The accuracy of the procedure was checked by determining Pb and Ni in standard reference tea leaves sample (GBW-07605). The results demonstrated good agreement with the certified values.

Determination of nickel in water by electrothermal atomic absorption spectrometry with preconcentration on a tungsten foil

A preconcentration method for nickel in waters involving adsorption on tungsten foil, followed by electrothermal atomic absorption spectrometry (ETAAS) with a tungsten tube atomizer is described. The most suitable pH for nickel adsorption was 5 and the optimum immersion time was 2 min. Severe interferences from co-existing elements (Al, Ca, Cu, Fe, K, Mg, Na, Pb and Zn) on the Ni AA signal were observed. Under optimal conditions, the preconcentration of nickel on W foil could eliminate interferences from these elements. The detection limit of nickel by preconcentration-ETAAS was 0.1 ng/ml (3S/N). The method with preconcentration on tungsten foil was applied to the determination of nickel in river water. The recovery of spiked nickel was 93–102%. The tungsten foil preconcentration method is sensitive, simple, and convenient. This adsorption method can be utilized inin situ-sampling of ultra-trace nickel in environmental samples (water). Furthermore, after sampling it is easy to carry and store the W-foil without contamination for long time.

Flow injection on-line coprecipitation-preconcentration system using copper(II) diethyldithiocarbamate as carrier for flame atomic absorption spectrometric determination of cadmium, lead and nickel in environmental samples

A novel flow injection (FI) on-line coprecipitation-preconcentration system with diethyldithiocarbamate (DDTC) Copper(II) being used as a carrier for the flame atomic absorption spectrometric determination of trace cadmium, lead and nickel was developed. Sample solutions, spiked with 120 μg ml −1 Cu 2+ and acidified to 0.5 M with hydrochloric acid, were merged online with a 2.1% DDTC solution in a ‘T’ connector upstream of a knotted reactor. The analytes were coprecipitated with DDTC-Cu 2+ and collected on the inner wall of the knotted reactor. The collected species were eluted with isobutyl methyl ketone, and the effluent was transported directly into the nebulizer. Enhancement factors of 26, 45 and 22 were obtained for cadmium, lead and nickel, respectively with a loading period of 30 s. The detection limits (3σ) for cadmium, lead and nickel were 0.23, 3.2 and 1.4 μg l −1 respectively, and the relative standard deviations ( n = 10) were 1.4% for 20 μg l −1 cadmium, 2.0% for 200 μg l −1 lead and 2.2% for 80 μg l −1 nickel. At least 50 mg l −1 of such metal ions as Fe 3+, Al 3+, Mn 2+, Zn 2+ and Co 2+, and 30 mg l −1 of Cu 2+ could be tolerated. The method has been successfully applied to the determination of trace cadmium, lead and nickel in various water samples and a standard reference soil.

Enhancement of atomic absorption sensitivity for cadmium, manganese, nickel, and silver and determination of submicrogram quantities of cadmium and nickel in environmental samples

Technical report: Studied were the enhancement effects of organic solids on nickel, manganese, cadmium, and silver using atomic absorption spectrometry. Ketones and acetate esters were the solvents that gave the greatest enhancement to the metals. A method that was used to detect heavy metals in water using ketone and acetate esters as solvents is described. Results of the tests indicate that cadmium and nickel levels in the waters of Tennessee and Kentucky are low. (4 graphs, 25 references, 7 tables)