Determination Of Mercury In Soils Research Articles

Determination of mercury in soil and water from a gold mining area in Karang Jaya Sub-district, Musi Rawas Utara, Indonesia

The present study focuses on the assessment of Hg distribution in both soil and water samples from the small-scale gold mining region of Karang Jaya Sub-district, Musi Rawas Utara Regency, South Sumatra Province. For over 30 years, this region has witnessed persistent utilization of mercury as an amalgam for gold extraction. The investigation encompasses an analysis of total mercury levels in soil samples obtained from Sukamenang, Muara Batang Empu, and Terusan Villages. As a comparative reference point devoid of gold mining activities, the neighboring Muara Lakitan Village was selected. The obtained results indicate a moderate to strong contamination level across the 30 sampled locations based on the Geoaccumulation Index (Igeo), with an average Igeo value of 2.6. Furthermore, Pollution Load Index (PLI) and Contamination Factor (CF) values demonstrate high contamination. Conversely, analysis of river water samples from 30 stations along the Rupit River reveals that most of the samples comply with quality standards (<0.0005 mg/L), with an average value at 0.000322 mg/L; only four stations exhibit total Hg concentrations surpassing regulatory thresholds. All soil and river water samples from the control area (10 stations) exhibited no signs of pollution. Appropriate investments in technology, finance, and technical skills are needed to reduce mercury pollution due to small-scale gold mining activities.

Portable and miniature mercury analyzer using direct sampling inbuilt-metal ceramic electrothermal vaporization

In this work, a small-size inbuilt-metal ceramic heater (IMCH) was for the first time utilized as a solid sampling electrothermal vaporizer (ETV), and then a novel direct sampling mercury analyzer coupled with a miniature atomic absorption spectrometer was thereby fabricated for sensitive determination of mercury in soil. The mercury analyzer is mainly composed of an IMCH-ETV, a catalytic pyrolysis furnace (CPF) using Al2O3 particles as a new filler, an atomic absorption spectrometer (AAS) and a miniature air pump for carrier gas; herein, the mostly used gold amalgamation was canceled. The IMCH with 30 W heating fulfills the 100% vaporization of mercury from up to 80 mg soil samples using 0.1 L min−1 air carrier. Under the optimized conditions, the method detection limit (LOD) was 0.4 ng g−1 for a 50 mg sample and the RSD of 11 repeated measurements of GSS-3a soil certified reference material (CRM) was 4%. Furthermore, the measured Hg values in various soil CRMs and real soil samples were within their certified values and consistent with that using the Chinese standard method (solid sampling catalytic pyrolysis AAS with gold amalgamation); and the recoveries were 85–113%, which proved favorable analytical accuracy and precision. This fabricated instrumentation only occupies 5 kg and 200 W power consumption vs. more than 25 kg and 1000 W for the traditional Hg analyzer. Therefore, the proposed IMCH-ETV-AAS method is very suitable for portable and rapid detection of mercury in soil.

Photochemical Vapor Generation for the Sensitive Determination of Mercury in Soil and Sediment Samples by Atomic Fluorescence Spectrometry

Photochemical Vapor Generation for the Sensitive Determination of Mercury in Soil and Sediment Samples by Atomic Fluorescence Spectrometry

Comparison of laser induced breakdown spectroscopy and spark induced breakdown spectroscopy for determination of mercury in soils

Mercury is a toxic element found throughout the environment. Elevated concentrations of mercury in soils are quite hazardous to plants growing in these soils and also the runoff of soils to nearby water bodies contaminates the water, endangering the flora and fauna of that region. This makes continuous monitoring of mercury very essential. This work compares two potential spectroscopic methods (laser induced breakdown spectroscopy (LIBS) and spark induced breakdown spectroscopy (SIBS)) at their optimum experimental conditions for mercury monitoring. For LIBS, pellets were prepared from soil samples of known concentration for generating a calibration curve while for SIBS, soil samples of known concentration were used in the powder form. The limits of detection (LODs) of Hg in soil were calculated from the Hg calibration curves. The LOD for mercury in soil calculated using LIBS and SIBS is 483ppm and 20ppm, respectively. The detection range for LIBS and SIBS is discussed.

Simple and accessible analytical methods for the determination of mercury in soil and coal samples

Simple and accessible analytical methods compared to conventional methods such as US EPA Method 7471B and ASTM-D6414 for the determination of mercury (Hg) in soil and coal samples are proposed. The new methods are consisted of fewer steps without the Hg oxidizing step consequently eliminating a step necessary to reduce excess oxidant. In the proposed methods, a Hg extraction is an inexpensive and accessible step utilizing a disposable test tube and a heating block instead of an expensive autoclave vessel and a specially-designed microwave. Also, a common laboratory vacuum filtration was used for the extracts instead of centrifugation. As for the optimal conditions, first, best acids for extracting Hg from soil and coal samples was investigated using certified reference materials (CRMs). Among common laboratory acids (HCl, HNO3, H2SO4, and aqua regia), aqua regia was most effective for the soil CRM whereas HNO3 was for the coal CRM. Next, the optimal heating temperature and time for Hg extraction were evaluated. The most effective Hg extraction was obtained at 120°C for 30min for soil CRM and at 70°C for 90min for coal CRM. Further tests using selected CRMs showed that all the measured values were within the allowable certification range. Finally, actual soil and coal samples were analyzed using the new methods and the US EPA Method 7473. The relative standard deviation values of 1.71–6.55% for soil and 0.97–12.11% for coal samples were obtained proving that the proposed methods were not only simple and accessible but also accurate.

Determination of mercury by nondispersive atomic fluorescence spectrometry

A nondispersive atomic fluorescence spectrometer for the determination of mercury by the cold-vapor technique has been developed. The conditions for mercury vapor generation in a hydride generator (the concentration and volume of the reagents, reaction and purge times, and argon flow rate) are optimized for fluorescence measurements. An algorithm is proposed for the calculation of the analytical signal that leads to an increase in the signal-to-noise ratio by a factor of 3 as compared to the conventional procedure. On the basis of the results obtained, procedures for the determination of mercury in soil and semolina samples are developed with a detection limit of 60 pg and RSD = 10%. The accuracy of the determinations is verified by an analysis of standard reference samples of soil and semolina.

Comparison of the Adsorbed Mercury Screening Method with Cold-Vapor Atomic Absorption Spectrophotometry for Determination of Mercury in Soil

ABSTRACT A field screening method for the determination of elemental mercury in environmental soil samples involves the thermal desorption of the mercury from the sample onto gold and then the thermal desorption from the gold to a gold-film mercury vapor analyzer. This field screening method contains a large number of conditions that could be optimized for the various types of soils encountered. In this study, the conditions were optimized for the determination of mercury in silty clay materials, and the results were comparable to the cold-vapor atomic absorption spectrophotometric method of determination. This paper discusses the benefits and disadvantages of employing the field screening method and provides the sequence of conditions that must be optimized to employ this method of determination on other soil types.

Determination of mercury in soils and sediments by graphite furnace atomic absorption spectrometry with slurry sampling

A graphite furnace atomic absorption spectrometric procedure for the determination of mercury is presented, in which the samples are suspended in a solution containing hydrofluoric and nitric acids. Silver nitrate (4% m/v) and potassium permanganate (3%) are incorporated, in the order specified, and aliquots are directly introduced into the graphite furnace. A fast heating programme with no conventional pyrolysis step is used. The detection limit for mercury in a 125 mg ml −1 suspension is 0.1 μg g −1. Calibration is performed by using aqueous standards. The reliability of the procedure is proved by analysing certified reference materials.

Closed-Ampule Digestion Procedure for the Determination of Mercury in Soil and Tissue Using Cold Vapor Atomic Fluorescence Spectrometry

Closed-Ampule Digestion Procedure for the Determination of Mercury in Soil and Tissue Using Cold Vapor Atomic Fluorescence Spectrometry

Determination of Total Mercury in Soils, Waste Water and Sewage Effluents

The cationic mercury(II)-1,10-phenanthroline binary chelate reacts with the acidic dye Thymol Blue (TB), in the pH range 5.2–7.0, to form an ion-pair extractable into chloroform. The effect of primary ligand and counter ion concentrations, pH, extraction solvent, extractability, standing time and co-existing ions has been thoroughly investigated. The molar absorptivity of the ion-pair, in chloroform, is 1.27×105 l.mol−1.cm−1 at 420 nm. The calibration graph is rectilinear for 0.09–1.72 μg ml−1 of mercury. The sensitivity index of the method is 0.0002 μg Hg.cm2– and the detection limit is 0.018 μg ml−1 of mercury. The stoichiometry of the extracted ion-pair is 1:2:1 (Hg-Phen-TB). The developed method has been successfully used to determine total mercury in soils, waste water and sewage effluents.

Determination of mercury in microwave-digested soil by laser-excited atomic fluorescence spectrometry with electrothermal atomization

A sample digestion procedure was developed which employs microwave heating of soil and sediment in concentrated nitric acid in a high-pressure closed vessel. Complete dissolution of mercury into the sample solution occurs within 5 min at 59 W/vessel without loss of analyte through overpressurization. Laser-excited atomic fluorescence spectrometry with electrothermal atomization (LEAFS-ETA) was used as the detection method. The scheme uses a two-step excitation, with λ 1 = 253.7 nm and λ 2 = 435.8 nm. Direct line fluorescence was measured at 546.2 nm. The absolute instrumental limit of detection was 14 fg; 1.4 pg/ml with a 10 μl sample injection. The recoveries of mercury in two spiked samples were 94 and 98%. The SRM 8406 (Mercury in River Sediment) was digested and analyzed for mercury, and the results (58.4 ± 1.8 ng/g) agreed well with the reference value of 60 ng/g. The results obtained by LEAFS-ETA with microwave sample digestion are in good agreement with those found by cold vapor atomic absorption spectrometry with EPA Series Method 245.5 sample digestion, which is one of the most commonly used methods for the determination of mercury in soil.

Spectrophotometric determination of mercury in soils with triphenyltetrazolium chloride

The formation of the acidocomplex of mercury(II) with triphenyl-tetrazolium chloride is studied spectrophotometrically in water-organic media. The composition of the complex is established as TTC:Hg:I = 1:1:1. The molar absorptivity ϵ 255 = (6.45 ± 0.12) × 10 4 1 mole −1. cm −1 is determined. The selectivity of the reaction is studied and the method for determination of mercury(II) 0.1–0.8 μg/ml is shown. Extraction investigations of the system discussed were carried out. The characteristic values for the extraction equilibrium and the equilibrium in the aqueous phase was determined: extraction constant K ex = 3.16 × 10 4, distribution constant K D = 20.67, and association constant = 1.53 × 10 3. 5 A rapid and sensitive extractive-photometric method for determination of mercury(II) in soil was developed. The determination was carried out without preliminary elimination of mercury.

Determination of Mercury In Soil by Cold Vapour AAS after its Separation with Aliquat-336

Determination of Mercury In Soil by Cold Vapour AAS after its Separation with Aliquat-336

Comparison of digestion procedures for the determination of mercury in soils by cold-vapour atomic absorption spectrometry

Five digestion procedures were investigated for the determination of mercury in soils by cold-vapour atomic absorption spectrometry. These methods included three acid leaching procedures in open systems and two acid digestion procedures in closed decomposition vessels. The closed vessels were heated in a conventional laboratory oven or a laboratory microwave oven. In the open systems, digestion with concentrated acids at elevated temperatures led to considerable losses of (organo) mercury compounds, while digestion at ambient temperature gave incomplete oxidation of the sample matrix. To prevent any losses of mercury and to obtain complete oxidation, the use of a closed decomposition system at elevated temperatures appeared to be necessary. The results obtained with these closed systems were in good agreement with those obtained by neutron activation analysis. Heating in a microwave oven appeared to be a considerable improvement over conventional thermal heating.

Extraction of mercury(II) from aqueous thiocyanate solutions with 5-(4-pyridyl)nonane in benzene, and its subsequent atomic-absorption spectrometric determination

Tracer (∼ 10 −8 M) mercury(II) can be quantitatively extracted with 5-(4-pyridyl)nonane in benzene from aqueous thiocyanate solutions that are up to 6 M in HCl, 1 M in H 2SO 4 or 0.25 M in HNO 3, in a single extraction. Optimal conditions for the extraction are given, based on a critical study of the relevant factors such as the effects of the acids, thiocyanate, salting-out and complexing agents and the reagent concentration. The mechanism underlying these extractions is discussed on the basis of the results obtained from partition and slope-analysis data. The extraction of the metal as Hg(PyN) 2(SCN) 2 is indicated. The extracted mercury can be stripped from the non—aqueous layer with various aqueous solutions, including nitric acid (⩾2 M), sodium citrate (⩾ 1 M) and sodium thiosulphate (⩾0.1 M). Common salts do not depress the extraction. Distribution coefficients and separation factors of several elements relative to mercury(II) are reported for media that contain the optimal concentrations of the mineral acids and are in 0.2 M in potassium thiocyanate. The data have been applied for the determination of mercury in soil and water samples by atomic-absorption spectrometry.

Comments on the Determination of Total Mercury in Soils and Sediments

Comments on the Determination of Total Mercury in Soils and Sediments

ChemInform Abstract: THE NEUTRON ACTIVATION ANALYSIS OF MERCURY IN SOIL

AbstractNach der Bestrahlung (Neutronenfluß 2·1013n cm‐1s‐1) wird die Bodenprobe mit einer HF/HClO4‐Mischung aufgeschlossen, das Hg radiochemisch durch Solventextraktion mit Toluol aus wäßriger H2SO4/KJ‐Lösung abgetrennt und schließlich als HgS gefällt.

The Neutron Activation Analysis of Mercury in Soil

Abstract A radiochemical neutron activation procedure has been designed for the determination of mercury in soils. After the irradiation of 100 mg of soil it was decomposed with a hydrofluoric and perchloric acid mixture in a platinum crucible, and the mercury was separated radiochemically by solvent extraction from sulfuric acid·potassium iodide media into toluene, followed by precipitation as a sulfide. The radioactivity of 197Hg was measured by using a Ge(Li) detector. The chemical yield, as determined by atomic absorption spectrophotometry, was high enough, and the precision was satisfactory. The detection limit is estimated to be 1–2 ppb [(1–2)×10−10 g] by this method. The above procedure was applied to the determination of mercury in soils sampled in the Kumamoto and Minamata districts and in between.

The incremental evolution, collection and determination of mercury in soils at the p.p.b. level as a function of temperature

The incremental evolution, collection and determination of mercury in soils at the p.p.b. level as a function of temperature

Determination of mercury in soils and biological matrices by the vanadium pentoxide digestion procedure.

The wet digestion procedure using catalytic amounts of vanadium pentoxide with sulfuric-nitric acid mixture developed in this laboratory for the analysis of mercury in cereals is extended to other biological substrates and soils. Investigations of the different parameters, such as temperature and concentration of vanadium pentoxide on the oxidation process indicate that 0.20 g of vanadium pentoxide was adequate to degrade 5.0 g of animal feed at 70–75°C. Studies have shown that excellent recoveries of mercury are obtained in spite of the presence of excess sulfur-containing amino acids and of certain metallic ions commonly present in soils. This digestion procedure is compared with that using potassium permanganate-sulfuric acid as oxidant to illustrate the significant advantages of this technique. It is found that less quantities of reagents and shorter duration of digestion are required for vanadium pentoxide oxidation than are necessary for potassium permanganate system. The probable role of vanadium pentoxide in the oxidation process is also discussed.