Atomic Absorption Determination Of Mercury Research Articles

Atomic absorption determination of mercury in urine by cold steam method using mercury- hydride prefix

Mercury is one of the most common in various industries and at the same time dangerous chemicals. It is able to be deposited in the body and have a toxic effect for a long time after the cessation of contact. Under the influence of mercury, workers can develop various intoxications, as a result of which pathological changes in the nervous, cardiovascular, endocrine, immune and reproductive systems are possible.Under production conditions, mercury enters the body, usually in the form of vapors (absorbed about 80%) and suspended particles. Inorganic forms of mercury are excreted mainly in the urine (60%). However, insufficient attention is currently being paid to the problem of determining the mercury content in urine samples. To date, in world practice there is no systematic approach to the determination of small doses of mercury in the body, as a result of which it is difficult to timely identify public health disorders. This is largely due to the lack of highly sensitive and highly effective methods of analysis, allowing routine measurements with minimal cost and high accuracy. The methods currently used are either quite expensive or have low accuracy/sensitivity.The aim of the study was to develop a method of atomic absorption determination of mercury in urine by cold steam, which would allow at minimal cost to increase the accuracy and sensitivity of mercury detection in the body.Materials and methods. Quantitative measurement of mercury in urine samples was carried out on an atomic absorption spectrometer with a mercury-hydride prefix using model solutions of different concentrations.Results. The study determined the optimal conditions for sample preparation of urine samples, set the range of concentrations for the construction of the calibration schedule, studied the effect of the matrix on the accuracy of the analysis by the “introduced-found” method. The lower limit of detection of the developed technique was 0.05 mcg/l, the upper limit–100 mcg/l (if necessary, it can be increased by additional dilution). The relative error of determination depending on the concentration varied from 3 to 15%.Conclusions. A highly sensitive, affordable and relatively inexpensive method for the determination of mercury in urine has been developed, which will allow to diagnose with high accuracy the background contents of mercury in urine, which is especially important when inspecting workers of industries associated with the use of mercury and its compounds, as well as the population living in areas close to these industries.

Survey study of mercury determination in detonation nanodiamonds by pyrolysis flameless atomic absorption spectroscopy

A set of 20 commercially available nanodiamond samples of eight manufacturers of various countries, which are most frequently used in basic and applied studies, was analyzed for the concentration of Hg. Conditions of mercury determination by flameless atomic absorption spectroscopy with thermal sample decomposition (pyrolysis) at 800°C were proposed and confirmed by wavelength-dispersive X-ray fluorescence analysis. It was found that nanodiamonds have a significant diversity of amounts of mercury, from 20μg/kg to higher than 0.7g/kg. Thus, the need to control Hg impurity in nanodiamonds, especially for biological and medical research, was demonstrated. The precision of flameless pyrolysis atomic absorption determination of mercury in nanodiamonds is discussed.

Atomic absorption determination of mercury in solid samples of placer gold

The possibility of atomic absorption determination of mercury in solid samples of placer gold is shown. Mercury-gold compounds with a variable composition are assumed to be found in the process of thermal atomization. The conditions that contribute to an increase in the degree of atomization of mercury in the process of heating of a solid sample in the range of concentrations above 10−7 wt % are selected.

Direct atomic absorption determination of mercury in drinking water and urine using a two-step electrothermal atomizer

A new method was developed for the direct electrothermal atomic absorption determination of mercury in drinking water and urine using double vaporization in a two-step atomizer with a purged vaporizer. In this method, a sample is placed in the vaporizer of a two-step atomizer, dried, and vaporized. The sample vapor is transferred to an unheated atomizer cell with a flow of argon and trapped by the inner surface of cell walls. This procedure can be performed repeatedly to preconcentrate mercury in the atomizer cell. Next, a portion of the sample transferred to the inner surface of the atomizer cell is revaporized and atomized by heating the atomizer cell of the two-step atomizer with a purged vaporizer, and the atomic absorption of mercury is measured. It was found that the degree of mercury transfer and trapping is as high as 100% at sufficiently high temperatures of primary vaporization, regardless of the material of the inner surface of the atomizer cell. The detection limits for mercury were 0.24 or 0.024 µg/L for drinking water at a sample volume of 100 µL using a single sample transfer or the procedure repeated ten times, respectively, and 2.0 µg/L for urine at a sample volume of 20 µL and a single sample transfer. The accuracy of the results was confirmed by the analysis of certified mercury samples and samples with known additives.

Investigation of Mercury(I) Dimedonate as a Reference Sample for Atomic-Absorption Spectrometry

It is shown that mercury(I) dimedonate meets the requirements imposed on the certified materials: it is homogenous and stable and the absolute value of the error of determination of mercury in a sample at P = 0.95 is 0.22%. A procedure is developed for the atomic-absorption determination of mercury in river water using the new reverence material.

Performance of the transverse heated filter atomizer for the atomic absorption determination of mercury

The transverse-heated filter atomizer (THFA) was used for the determination of Hg in aqueous solutions and organic solvent (IBMK) after the extraction of Hg with dithizone. The THFA design was similar to one previously described. The injected sample was distributed over the graphite fibre in the ring cavity between the external pyrocoated tube and internal tube–filter made of porous graphite. When the samples were atomised the Hg vapours entered the analytical zone along the tube axis through the porous walls of the inner tube. The aqueous or organic solutions of Hg can be directly analysed in the THFA without the addition of matrix modifiers, using the pyrolysis temperatures 500 and 400 °C, respectively, and an atomization temperature of 1300 °C. The addition of 0.1 µg Pd to the organic sample made it possible to increase the pyrolysis temperature to 500 °C. In comparison with the transverse-heated graphite atomizer (THGA), where sample volumes of 50 µl and 20 µl for aqueous and organic solutions, respectively, are used, large sampling volumes of 100–140 µl can be used with the THFA without distortion of the calibration curve. High sampling and drying temperatures provide an analysis cycle of approximately 40 s (without sampling time) for large volumes. The characteristic mass obtained for the determination of Hg in the THFA was found to be 55 and 79 pg, with and without the 0.1 µg Pd modifier, respectively, compared to 228 pg for aqueous solutions in the presence of 20 µg Pd in the THGA. Several reference materials were analysed directly or after extraction of the Hg by dithizone in IBMK. The results showed good agreement with the certified values.

The matrix effect in the cold-vapor atomic absorption analysis of mercury in environmental samples.

In contrast to analyses of biological samples, the cold-vapor atomic absorption determination of mercury in environmental samples exhibits essentially no matrix effect.

Cold Vapor Atomic Absorption determination of mercury by Flow Injection Analysis using a Teflon membrane phase separator coupled to the absorption cell

A Flow Injection Analysis (FIA) procedure for the determination of trace amounts of mercury by the Cold Vapor Atomic Absorption (CVAA) method is presented. In order to make efficient use of the FIA technique, a new flow cell was developed to permit a rapid separation of elemental mercury from the carrier solution. The design of this device is based on the permeability of Hg 0 in commercially available Teflon (PTFE) tape, which acts as a membrane phase separator. The calibration curve is linear up to 70 ng.ml −1 ( A = 0.005 + 0.008 Hg(ng.ml −1); r = 0.9996) using a 15-cm open cell approach, with a detection limit of 1.4 ng. ml −1 (0.66 ng of mercury), considering a signal to noise ratio of three. The standard deviation is s = ±0.004 absorbance units, calculated at a level of 50 ng.ml −1 of Hg 2+. The sampling rate was 110 samples per h.

Atomic-absorption determination of mercury in geological materials by flame and carbon-rod atomisation after solvent extraction and using co-extracted silver as a matrix modifier

Based on modifications and expansion of the original Tindall's solvent extraction flame atomic-absorption procedure, an atomic-absorption spectrophotometric method has been developed for the determination of mercury in geological materials. The sample is digested with nitric and hydrochloric acids in a boiling water-bath. The solution is made ammoniacal and potassium iodide and silver nitrate are added. The mercury is extracted into isobutyl methyl ketone as the tetraiodomercurate(II). Added silver is co-extracted with mercury and serves as a matrix modifier in the carbon-rod atomiser. The mercury in the isobutyl methyl ketone extract may be determined by either the flame- or the carbon-rod atomisation method, depending on the concentration level. The limits of determination are 0.05–10 p.p.m. of mercury for the carbon-rod atomisation and 1–200 p.p.m. of mercury for the flame atomisation.Mercury values for reference samples obtained by replicate analyses are in good agreement with those reported by other workers, with relative standard deviations ranging from 2.3 to 6.9%. Recoveries of mercury spiked at two levels were 93–106%. Major and trace elements commonly found in geological materials do not interfere.

A study of the disproportionation of mercury(I) induced by gas sparging in acidic aqueous solutions for cold-vapor atomic absorption spectrometry

Instrumentation and procedures for the cold-vapor atomic absorption determination of mercury have been modified. Samples are analyzed by syringe injection under reducing and non-reducing conditions so as to allow mercury valence state differentiation. It is shown that chloride ion is effective in preventing mercury(I) disproportionation; in the absence of a strong mercury(II) complexing ligand, mercury(I) readily disproportionates when solutions are sparged with nitrogen. The data are consistent with the formation at the 10–500 ppb level of a Hg 2Cl 2 precipitate with a lower solubility product than the literature values.

Problems with sub-p.p.b. mercury determinations: preservation of standards and prevention of water mist interferences

Instrumentation, for the cold-vapor atomic absorption determination of mercury has been improved by several modifications including an a.c.—d.c. switching circuit; a single module for the light source, beam splitter, and reference PMT; and the use of an electrically heated glass tube to vaporize water mist, in place of the conventional magnesium perchlorate drying tube. Its use to study the effectiveness of nine common oxidizing agents as preservatives for sub-p.p.b. concentrations of mercury(II) in distilled water has shown that only combinations of nitric acid with potassium dichromate or gold(III) are suitable.

Temperature Effects in Mercury Analysis

Abstract Flameless atomic absorption determination of mercury involves blowing elemental mercury from reducing solution into a spectrophotometer cell. The temperature of the reducing solution greatly affects the rate at which mercury comes out of solution, and thus, if not kept constant, can affect analytical results.

Some comments on interferences by Cu(II) ions and Ag(I) ions on the wet reduction-flameless atomic absorption determination of mercury

Some comments on interferences by Cu(II) ions and Ag(I) ions on the wet reduction-flameless atomic absorption determination of mercury

Simple device for compensation of broad-band absorption interference in flameless atomic absorption determination of mercury

Simple device for compensation of broad-band absorption interference in flameless atomic absorption determination of mercury