Nickel In Biological Samples Research Articles

Measurements of sulfur, phosphorus and nickel in biological samples like bovine liver by atomic emission spectroscopy

The work considers the method of atomic emission spectroscopy, the preparation of laboratory plasticware, the preparation of samples, the parameters of the spectrometer and processing measurement results are given. As confirmation of the correctness of the measurements, the results of the international comparison CCQM-K145 are presented.

Controlling Contamination for Determination of Ultra-Trace Levels of Cr and Ni in Biological Materials in a Conventional Laboratory

The determination of ultra-trace levels of chromium and nickel in biological samples had previously been very difficult due to serious contamination problems in conventional laboratories. Contamination control in a conventional laboratory was studied and contamination due to various sources was minimized systematically. In addition to chromium and nickel, zinc was also determined as an indicator element prone to contamination. Measurements were carried out using electrothermal atomic absorption spectrometry (ETAAS). Contamination from the sample handling steps, digestion vessels, atmospheric fallout, and the effect of the liquid contact area were studied. In the sample handling steps, even simple procedures, such as transferring the sample solution from the volumetric flask by pouring, led to significant contamination due to the large area of liquid contact. This contamination source was eliminated by transferring the sample solution using an automatic pipette. The most suitable method for decontamination of the digestion vessels was steaming with boiling nitric acid as opposed to leaching with nitric acid at room temperature. Quartz was found to be a more suitable digestion vessel material than Teflon-PFA when Cr and Ni were determined. For Zn determination, Teflon-PFA was more suitable. Contamination from atmospheric fallout was highest in the fume hood and was reduced by simply closing the labware into Minigrip® bags before use. The surface area of the labware in contact with the handled liquid volume should be kept at a minimum because even a simple procedure, such as preparing standard solutions in volumetric flasks, can lead to significant contamination if the vessel surface area is too large. Finally, low enough contamination was achieved so that the total procedure blanks were below the instrumental detection limits for Cr and Ni.

Selective Determination of Nickel in Biological Samples by High Performance Liquid Chromatography

A highly selective method for the determination of trace amounts of nickel(II) by high performance liquid chromatography was developed. 2-[(2-Hydroxyphenyl)azo]-4,5-diphenylimidazole (HAI) was used for pre-column derivatization of nickel(II) in reversed-phase chromatographic separation followed by spectrophotometric detection. In the presence of nickel(II), iron(III), cobalt(II), copper(II), cadmium(II), zinc(II), manganese(II), aluminum(III) and vanadium(V), only nickel(II) chelate with HAI gave a resolved peak in chromatograms with a C8-bonded reversed phase column and a 45% (w/w) acetonitrile-water mobile phase containing 1.0 × 10−4 mol kg−1 ethylenediaminetetraacetic acid and 5.0 × 10−3 mol kg−1 sodium acetate (pH 7.5). The nickel(II) chelate was detected spectrophotometrically at 585 nm. When 100 µL of a test solution was injected, the calibration graph was linear up to 240 pg for nickel(II), and the detection limit defined as three times the standard deviation of the reagent blank was 0.8 pg at 0.001 absorbance unit full scale. The proposed method was applied to the analysis of rice, tea leaves and mussels.

Determination of copper, manganese and nickel in biological samples and sea-water by flow injection on-line sorption preconcentration in a knotted reactor coupled with electrothermal atomic absorption spectrometry

A flow injection system with on-line sorption preconcentration of copper, nickel and manganese with ammonium pyrrolidinedithiocarbamate (APDC) or 8-hydroxyquinoline (HQ) in a knotted reactor (KR) coupled with electrothermal atomic absorption spectrometry was developed. APDC offered better performance characteristics than HQ for the preconcentration of copper and nickel but could not be employed for manganese. The performance characteristics of the determination of copper and nickel with APDC were: detection limits (3σ), 6.0 and 7.6 ng l–1, precision (RSD) 2.5% for 0.2 µg l–1 and 1.5% for 0.2 µg l–1 and enhancement factors 44 and 21 using a 30 s preconcentration time. The corresponding parameters for the determination of manganese with HQ were detection limit 29.0 ng l–1, precision (RSD) 2.9% for 0.4 µg–1 manganese and enhancement factor 8 with a 30 s preconcentration time. The sampling frequency was 26 h–1. The accuracy of the method was demonstrated by the analysis of certified reference materials and by recovery measurements on spiked samples.

On-line flow injection solvent extraction for electrothermal atomic absorption spectrometry: Determination of nickel in biological samples

A flow injection (FI) on-line solvent extraction system for electrothermal atomic absorption spectrometry (ETAAS) was developed with nickel as a model trace element. The nickel pyrrolidine-dithiocarbamate chelate was extracted on line into isobutyl methyl ketone, which was delivered into the FI system by a peristaltic pump equipped with poly(tetrafluoroethylene) tubing. The organic phase was separated from the aqueous phase by a novel gravity phase separator with a small conical cavity, and stored in a collector tube, from which 50 μl organic concentrate was introduced into the graphite tube by an air flow. ETAAS determination of the analyte was performed in parallel with the extraction process. An enrichment factor of 25 was obtained in comparison with 50 μl direct introduction while achieving a detection limit of 4 ng l −1 (3σ), and a precision of 1.5% relative standard deviation for 1.0 μg l −1 nickel ( n = 11). The proposed method was successfully applied to the determination of nickel in body fluids and other biological samples.

Determination of nickel in biological samples prepared by microwave dissolution using electrothermal atomic absorption spectrometry after extraction with 1,5-bis[pheny-(2-pyridyl)methylene]thiocarbonhydrazide

An electrothermal atomization atomic absorption spectrometric method for the determination of traces of nickel after extraction of the metal into methyl isobutyl ketone containing 1,5-bis[phenyl(2-pyridyl)methylene] thiocarbonhydrazide is suggested. The chief advantage of the method lies in its maximum allowable aqueous-to-organic phase volume ratio of 37. The method was applied to the determination of nickel in various biological tissues, serum and human urine.

Determination of nickel in biological samples by inductively coupled plasma atomic emission spectrometry after extraction with 1,5-bis[phenyl-(2-pyridyl)methylene]thiocarbonohydrazide

A sensitive inductively coupled plasma atomic emission spectrometric method for the determination of trace amounts of nickel after extraction of the metal into isobutyl methyl ketone (IBMK) containing 1,5-bis[phenyl(2-pyridyl)methylene]thiocarbonohydrazide (BPTH) is described. A systematic study was made to determine the optimum conditions for extraction of the metal into IBMK. The chief advantage of the method lies in the maximum allowable aqueous-to-organic phase volume ratio of 37. The detection and quantification limits for nickel were 0.3 and 1.1 ng ml–1, respectively, and the calibration is linear from 0.4 to at least 150 ng ml–1. The method has been used for the determination of nickel in various biological samples [mineralized by microwave digestion in sealed poly(tetrafluoroethylene) containers], as well as in human urine, with good results.

Determination of nickel in biological samples by ETA-AAS and ICP-AES after acidic dissolution (with microwave heating and preconcentration by liquid-liquid extraction)

The determination of nickel by ETA-AAS and ICP-AES in biological samples with prior extraction into methyl isobutyl ketone with 1,5-bis(di-2-pyridylmethylene) thiocarbonohydrazide as extracting reagent is described. Microwave dissolution in closed teflon vessels has been used for the dissolution of biological materials. At least three samples can be decomposed simultaneously with a preset heating programme. Results of analyses of some certified biological reference materials are given.

Flame Atomic Absorption Spectrometric Determination of Cadmium, Cobalt, and Nickel in Biological Samples Using a Flow Injection System with On-Line Preconcentration by Co-Precipitation without Filtration

Cadmium, cobalt, and nickel at ng/g to μg/g levels in plant and animal tissue reference materials and at μg/L levels in blood and urine were determined by flame atomic absorption spectrometry. The analyte elements were preconcentrated and separated from the bulk of the matrix by on-line co-precipitation with the hexamethylene ammonium hexamethylene dithiocarbamate iron(II) chelate complex in a flow injection system. The precipitate was collected in a knotted reactor made from 150-cm-long, 0.5-mm-i.d. Microline tubing without using a filter. The precipitate was dissolved in methyl isobutyl ketone and introduced directly into the nebulizer-burner system of an atomic absorption spectrometer. Ascorbic acid in an HC1/KC1 buffer was added on-line in order to reduce iron(III) to iron(II) because of its much better efficiency as a collector for trace elements. Reagent concentrations were optimized so that at least 200 mg/L of iron and 15 mg/L of copper could be tolerated in the sample solution without causing significant interferences. The portion of the analyte retained in the collector was about 70% for cadmium and 50% for cobalt and nickel. Enrichment factors of 24, 19, and 20 were obtained for cadmium, cobalt, and nickel, respectively, with the use of a 40-s co-precipitation time, resulting in enhancement factors, including the effect of the organic solvent, of 52, 43, and 52, respectively. The detection limits (3 σ) for cadmium, cobalt and nickel were 0.15, 1.3, and 1.5 μg/L, respectively, and the precision was 1.5% RSD for 10 μg/L Cd, 2.7% RSD for 50 μg/L Co, and 1.8% RSD for 50 μg/L Ni. The analytical results obtained for a number of standard reference materials and control samples were in good agreement with the certified or recommended values.

Determination of Nickel in Biological Samples by Electrothermal Atomization-Atomic Absorption Spectrometry Involving a Prior Extraction with 1,5-Bis (Di-2-Pyridylmethylene) Thiocarbono-Hydrazide

Abstract The use of 1,5-bis(di-2-pyridylmethylene) thiocarbono-hydrazide as a reagent for the extraction of Ni(II), Co(II), Zn(II), Fe(II), Cd(II) and Cu(II) into methyl isobutyl ketone has been studied, and a method for the determination of nickel at ultra-trace (ng/ml) level has been developed, by using electrothermal-atomization (graphite furnace) atomic absorption spectrometry involving a prior extraction with the cited extracting reagent. The chief advantage of the proposed method lies in its maximum allowed aqueous-to-organic phase volume ratio of 15. It has been successfully applied to the determination of nickel substrates in various biological samples.

Determination of nickel in biological samples by inductively coupled plasma spectrometry after extraction with 1,5-bis(di-2-pyridylmethylene)thiocarbonohydrazide

An ICP-AES method for the determination of nickel subtraces after extraction of the metal into methyl isobutyl ketone(MIBK) containing 1,5-bis-(di-2-pyridylmethylene)thiocarbonohydrazide is suggested. The complex formed is quite soluble in MIBK, so that the determination of concentrations down to 15 times lower than those by the direct non-extractive method is possible. In addition, the extraction step enhances the selectivity. The described method was applied to the determination of nickel in various biological materials, such as red cabbage, algae, liver, kidney, brain and urine.

Isotope dilution gas chromatography/mass spectrometry for the determination of nickel in biological materials.

Precise and accurate methods are required to measure nickel in urine and serum samples to identify clinical states of either deficiency or toxicity. This paper presents an isotope dilution gas chromatography/mass spectrometry method for the measurement of nickel in biological samples. The method involves the preparation of a thermally stable and volatile nickel chelate using lithium bis(trifluoroethyl)dithiocarbamate as the chelating agent. Conditions were optimized for the digestion of the sample and quantitative preparation of chelate as well as the precise and accurate measurements of the isotope ratios using a capillary column gas chromatograph with a general purpose mass spectrometer. The memory effect between samples of different isotope ratios was evaluated and was found to be negligible. The quantitative accuracy of isotope dilution was validated by measuring nickel in the NIST freeze-dried urine reference material, SRM 2670, with comparison to the recommended value.

Database for trace element concentrations in biological samples

Numerous methods have been published for the determination of the concentration of elements such as arsenic, cadmium, chromium, mercury and nickel in biological samples as blood, tissues and urine. It is not easy but highly desirable to assess the reliability of such methods. Several publications present values of trace element levels in samples from apparently healthy subjects as well as from persons with different diseases and after various exposures. Very often published “normal values” for unexposed subjects differ much — even up to one order of magnitude. There are major problems related to sampling, definition of the reference groups and analysis. Values for such groups can be called reference values rather than normal values. Therefore it is difficult even for experts to find such accurate and typical values to be used for comparative purposes e.g. in toxicology and occupational medicine. Knowledge is desirable of an average value and also of the respective frequency distribution. In this paper factors are discussed influencing the values such as selection of the reference groups and how to get typical reference intervals. We have worked for several years with developing methods for trace element determination and with evaluating data for use in e.g. occupational health. Therefore we felt a need for systematic evaluation accessible through a database. The original publications are retrieved by careful literature data search in e.g. Medline and Chemical Abstracts. We plan to offer discettes with evaluated typical concentrations of elements, specified details of sampling and analysis, reliability as well as references to the original publications. These discettes are very easy to use. A frequently updated and easily accessible database system should be very useful. Cooperation is planned with e.g. International Commission on Occupational Health, International Atomic Energy Agency (IAEA), International Labour Organization (ILO), International Union of Pure and Applied Chemistry (IUPAC), National Institute of Occupational Safety and Health (NIOSH in USA) and the World Health Organization (WHO).

Biological monitoring of nickel.

Measurements of nickel in body fluids, excreta, and tissues from humans with occupational, environmental, and iatrogenic exposures to nickel compounds are comprehensively reviewed. Correlations between levels of human exposures to various classes of nickel compounds via inhalation, oral, or parenteral routes and the corresponding concentrations of nickel in biological samples are critically evaluated. The major conclusions include the following points: Measurements of nickel concentrations in body fluids, especially urine and serum, provide meaningful insights into the extent of nickel exposures, provided these data are interpreted with knowledge of the exposure routes, sources, and durations, the chemical identities and physical-chemical properties of the nickel compounds, and relevant clinical and physiological information, such as renal function. Nickel concentrations in body fluids should not, at present, be viewed as indicators of specific health risks, except in persons exposed to nickel carbonyl, for whom urine nickel concentrations provide prognostic guidance on the severity of the poisoning. In persons exposed to soluble nickel compounds (e.g., NiCl2, NiSO4), nickel concentrations in body fluids are generally proportional to exposure levels; absence of increased values usually indicates non-significant exposure; presence of increased values should be a signal to reduce the exposure. In persons exposed to less soluble nickel compounds (e.g., Ni3S2,NiO), increased concentrations of nickel in body fluids are indicative of significant nickel absorption and should be a signal to reduce the exposures to the lowest levels attainable with available technology; absence of increased values does not necessarily indicate freedom from the health risks (e.g., cancers of lung and nasal cavities) associated with exposures to certain relatively insoluble nickel compounds.