A specific method for the spectrophotometric determination of palladium with N,N'-diphenylbenzimidoylthiourea (DPBITU) is described. The method in new, simple, rapid and applicable over 0.3-1.0 M HCl and free from interferences of the precious metals i.e. Ag, Au, Pt, Ir, Rh, Ru, Os. The value of molar absorptivity of the complex in the term of Pd is (2.50)x10(4) L mole(-1) cm(-1) at lambda(max) 365 nn in chloroform. The detection limit of the method at 3 sigma is 80 ppb Pd. The composition of the complex and effect of diverse ions in the determination of Pd are discussed. The application of the method has been tested for the analysis of the metal in catalytic material.

Lead (Pb) is of major environmental concern due to its toxicological importance. The anthropogenic emission of Pb is at least 100 times higher than natural emissions. Soil and dust are significant sources of Pb exposure. Lead is generally immobile in soil and accumulates in the upper layers. Lead particles may enter homes via shoes, clothes, pets, and windows. Central India is rich in deposits of natural resource materials such as coal, pyrite, dolomite, and alumina that contain Pb and other heavy metals at the trace levels, and the substantial exploitation of these materials has tended to increased contamination of water and geological formations. Here we present data on Pb concentrations in the water, soil and sediment samples (n=158) collected from 70 locations in Chhattisgarh state, Raipur region. Lead concentrations in the surface water (n=44), groundwater (n=44), soils (n=60) and sediments (n=10) ranged from 6 to 1410, 3 to 52, 12.8 to 545, and 31 to 423 μg g−1, with mean values of 305, 16, 102 and 190 μg g−1, respectively. Most of the Pb fractions of >80% can be leached out with the chemical extractants EDTA, acetic acid, and hydroxylamine hydrochloride. Lead has accumulated in the soil clay fraction due to its relatively large surface area and decreases with increasing depth in the soil profile.

A new, simple, rapid, and selective procedure for the flow injection analysis (FIA) spectrophotometric determination of platement (Pt) is described. The method is based on the color reaction of Pt(IV) with SnCl2 in the HCl medium. The mixed surfactants, i.e., cetylpyridinium chloride (CPC)+triton X-100 (TX-100) are used to enhance sensitivity of the method. The value of apparent molar absorptivity in the term of Pt is (3.00)x10 3 L mol(-1) cm(-1) at absorption maximum, 405 nm. The detection limit (causing absorbance greater than 3xstd. dev.) of the method is 150 ng/mL -1 . The optimum concentration range for the determination of Pt is 0.5-18 mu g/mL(-1) with slope, intercept and correlation coefficient 0.0086, -0.001, and +0.99, respectively. The sample throughput of the method is 120 samples/h(-1) at the flow rate of 3.7 mL/min(-1) . The composition of the complex, and the reaction mechanism involved are discussed. The effect of FIA and analytical variables on the determination of the metal is optimized. The method has been tested for the analysis of Pt to the catalytic materials.

Arsenic contamination in the environment (i.e. surface, well and tube-well water, soil, sediment and rice samples) of central India (i.e. Ambagarh Chauki, Chhattisgarh) is reported. The concentration of the total arsenic in the samples i.e. water (n=64), soil (n=30), sediment (n=27) and rice grain (n=10) were ranged from 15 to 825 μg L−1, 9 to 390 mg kg−1, 19 to 489 mg kg−1 and 0.018 to 0.446 mg kg−1, respectively. In all type of waters, the arsenic levels exceeded the permissible limit, 10 μg L−1. The most toxic and mobile inorganic species i.e. As(III) and As(V) are predominantly present in water of this region. The soils have relatively higher contents of arsenic and other elements i.e. Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Ga, Zr, Sn, Sb, Pb and U. The mean arsenic contents in soil of this region are much higher than in arsenic soil of West Bengal and Bangladesh. The lowest level of arsenic in the soil of this region is 3.7 mg kg−1 with median value of 9.5 mg kg−1. The arsenic contents in the sediments are at least 2-folds higher than in the soil. The sources of arsenic contamination in the soil of this region are expected from the rock weathering as well as the atmospheric deposition. The environmental samples i.e. water, soil dust, food, etc. are expected the major exposure for the arsenic contamination. The most of people living in this region are suffering with arsenic borne diseases (i.e. melanosis, keratosis, skin cancer, etc.).

Aminoantipyrine is a widely used reagent for spectrophotometric determination of PhOHs. Since its colour development lasts rather long, there was a need for a new, simple method for spectrophotometric determination of phenols in wastewater. In the new approach, PhOH reacts with vanadium(V) and N-hydroxy-N,N'-diphenylbenzamidine (HODPBA) to form blue-coloured complex extractable to chloroform. Its apparent molar absorptivity is 1.00 x 10(4) L mole(-1) cm(-1) at lambda(max) = 600 run. The method provides detection limit of 30 ng mL(-1). Calibration curve is linear up to PhOH concentration of 3.0 mu g mL(-1). Calibration plot parameters were as follows: enrichment factor 5, slope- 0.1053, intercept- 0.0005, and correlation coefficient +0.99. Determination conditions were optimised in the course of analysis. The proposed method was found to be highly selective towards the determination of PhOH. It has been applied to the determination of PhOH in municipal and industrial wastewater samples.

Abstract A simple and specific method for flow injection analysis (FIA) spectrophotometric determination of Pd is described. The method is based on color reaction of Pd(II) with organic reagent, i.e., N‐phenylbenzimidoylthiourea (PBITU) over acidity range, 0.2–2.0 M HCl in the 10% (v/v) ethanolic solution. The value of apparent molar absorptivity of the yellow colored complex in the term of Pd is 1.20 × 104 L mol−1 cm−1 at λmax 345 nm. The detection limit (causing more absorbance than 3s) of the method is 80 ng mL−1 of Pd. The optimum working range was 0.25–10.0 µg mL−1 of Pd with slope, intercept, and correlation coefficient of 0.059, 0.006, and +0.99, respectively. The RSD of the method was ±1.1% for six replicate measurements at level of 2.0 µg mL−1 of Pd. The sample throughput of the method is 120 samples hr−1. The composition of the complex is discussed. The method is specific for the determination of Pd as none of the tested ions interfered. The method has been applied for the determination of Pd in the catalytic materials.

A new simple flow injection analysis (FIA) procedure for the spectrophotometric determination of cationic surfactants (CSs), i.e. dodecyltrimethylammonium bromide (DTAB), cetyltrimethylammonium bromide (CTAB), and cetylpyridinium chloride (CPC), is described. The method is based on absorptivity enhancement of the Bi(III)-I− complex in the presence of CSs. Among the investigated compounds, highest sensitivity is obtained with CPC, so it was selected for detailed study. The apparent value of molar absorptivity of the complex in terms of CPC is (6.00)×103 L mol−1 cm−1 at λmax 505 nm for FIA determination. The detection limit (3σ criterion) of the method for FIA determination is 110 µg L−1. The sample throughput is >140 samples h−1. The effect of analytical and FIA variables in the determination of CPC is described. The composition of the complex is discussed. The method is free from interferences of common ions. The method has been applied to the analysis of surfactant contamination in environmental samples, i.e. pond water, municipal/industrial wastewater, sewage, sediment and soil.

From July 1997 to June 1998 aerosol particle samples (diameter 0.1–25μm) were collected at Kleiner Feldberg (Taunus mountains, Germany), a rural location that is temporarily influenced by the nearby urban Rhein-Main area and/or by long-range transport from East Germany and Eastern Europe. The atmospheric concentrations of the elements sodium to lead (11⩽Z⩽83) were determined by total reflection X-ray fluorescence analysis. Size, morphology and chemical composition of more than 27,000 individual aerosol particles were determined by high-resolution scanning electron microscopy and energy-dispersive X-ray microanalysis. Based on morphology and chemical composition the particles were classified in the particle groups: ammonium sulfates, calcium sulfates, sea salt, alumosilicates, silica, metal oxides/hydroxides, soot, biological particles, carbon/sulfate mixed particles, and remaining carbon-rich particles (Crest). Polluted air masses at Kleiner Feldberg are characterized by high number concentrations of soot (up to 80% in the size range from 0.1 to 0.2μm), metal oxides and sulfates. Anthropogenic and natural sources of alumosilicates, silica and metal oxides/hydroxides are easily distinguished by their morphology. From the size resolved relative abundance of the different particle groups the total and the size resolved complex refractive index (CRI) of the dry particulate matter (λ=550nm) was calculated for the different sampling days. Urban influenced air masses are characterized by high real (1.60–1.73) and imaginary parts (0.034–0.086) of the total CRI, rural air masses by lower real (1.54–1.61) and imaginary parts (0.001–0.021). The high real parts of the CRI of polluted air masses are predominantly caused by the high abundance of metal oxide/hydroxide particles, the high imaginary parts by high abundances of soot.

The present work proposes a new, simple, selective, and sensitive method for the on-site spectrophotometric determination of SCN- ions in the industrial and municipal waste water. The method is based on color reaction of SCN- ions with V(V) and chelating agent: N-hydroxy-N,N'-diphenylbenzamidine (HODPBA), and subsequent extraction of the deep green colored complex into chloroform. The value of apparent molar absorptivity (at enrichment factor of 5) is 7.00 x 10(3) Lmol(-1) cm(-1) at lambda(max) = 610 nm. The calibration curve is linear up to 5.0 mug mL(-1) SCN- with slope, intercept, and correlation coefficient of 0.120, 0, and +0.99, respectively. The detection limit (an absorbance identical to blank absorbance +thrice of std. dev.) of the method is 66 ng mL(-1) SCN- of the aqueous solution. Most of the ions associated did not interfere in the determination of SCN-. Only phenol interfered in the determination of SCN-, and could be removed by the prior extraction with chloroform solution. The method has been used for analysis of SCN- in industrial and municipal waste water samples.

As part of the study on “Reference Asian Man” project, dried food from different Asian countries, in powdered form, was analyzed applying different techniques. Boron was determined by measuring prompt alphas in 11B(p,α)8Be reaction with 800 keV protons. Coulomb excitation was used for F and Na determination based on 19F(p,p'γ)19F (γ -rays: 110 and 197 keV) and 23Na(p,p'γ)23Na (γ -ray: 440 keV) reactions with 2.3 MeV protons. The elements Sc, Co, Zn, Rb, Ag and Ce were determined by neutron activation analysis. The elements Ca, Mn, Fe, Ni, Cu, Zn, Sr and Mo were determined by X-ray fluorescence technique.

A new, simple, rapid, selective, and sensitive flow-injection analysis (FIA) method for the spectrophotometric determination of Bi is described. It is based on reaction of Bi (III) with I- ions in the presence of cationic surfactants (CS), i.e., cetylpyridinium chloride, cetyltrimethylammonium bromide, tetradecyltrimethylarnmonium bromide, dodecyltrimethylarnmonium bromide in sulfuric media to give a violet-colored complex. The apparent value of molar absorpitivity of the complex in the terms of Bi with four CSs lie in the range of (1.00-1.20) x 10(4) Lmol(-1)cm(-1) at lambda(max) 490 nm. Among them, the most sensitive CSs, i.e., cetylpyridinium chloride (CPC) has been selected for the detailed studies. The detection limit (causing absorbance > 3 sec) of the method is 65 mug L-1 Bi. The sample throughput of the method is > 120 samples hr(-1). The effect of diverse ions and surfactants in the FIA determination of Bi is examined. The composition of the complex is discussed. The analytical and FIA variables in the determination of Bi are optimized. The method has been applied for analysis of Bi in the environmental and pharmaceutical materials.

A Merovingian crucible fragment, with internally adhering yellow glass, and yellow glass beads of the same region and period were investigated by non‐destructive XRF, optical microscopy and SEM‐EDS. Although the microstructure and chemical composition of the yellow pigment (lead–tin yellow type II, ‘PbSnO3’) are almost identical in both the beads and the crucible, in the latter the pigment occurs in a much higher concentration. However, the glass base in the beads and the crucible is very different, indicating that the beads were not manufactured directly from the crucible. Instead, the crucible most likely served to produce lead–tin yellow, which was subsequently mixed elsewhere with a colourless soda–lime glass to produce yellow glass beads.

During the Lindenberger Aerosol Characterization Experiment (LACE 98), impactor sampling of aerosol particles in the size range of 0.1 to 25 μm was performed. The atmospheric concentrations of the elements sodium to lead (11 ≤ Z ≤ 83) were determined by total reflection X‐ray fluorescence analysis. Approximately 15,500 individual particles were examined by high‐resolution scanning electron microscopy and energy‐dispersive X‐ray microanalysis, and about 3800 particles were examined by transmission electron microscopy combined with energy‐dispersive X‐ray microanalysis. On the basis of morphology and chemical composition the particles were classified into 10 different groups: ammonium sulfates, calcium sulfates, sea salt, metal oxides/hydroxides, carbonates, silicates, soot, biological particles, carbon/sulfate mixed particles, and rest of carbon‐rich particles Crest. The phases present in the different particle groups were determined by selected area electron diffraction in the transmission electron microscope. In addition, the heterogeneous phase composition of agglomerates was studied in detail. On the basis of the size distribution and the relative abundance of the particle groups, the average and size‐resolved complex refractive index of the total aerosol were calculated. The real part of the average refractive index mainly depends on the abundance of metal oxide/hydroxide particles and varied between 1.52 and 1.57 on the different sampling days. The average imaginary part varied between 0.031 and 0.057 depending on the amounts of soot and carbon/sulfate mixed particles. The average complex refractive index deduced from the analysis of individual aerosol particles is in good agreement with the results of photometer measurements of dried filter samples.

The Fe(II)/Fe(III)-partition in cloudwater samples collected during two field campaigns is evaluated. It turned out that the simultaneous occurrence of complexing and reducing substances in the atmosphere and the cloud processing increase the solubility of iron compounds present in aerosol particles. A correlation between the concentration of iron(II) in the liquid phase and the intensity of the solar irradiation was observed for most of the cloudwater samples. This could be due to the fact that both the photochemical reduction of the iron(III) complexes and the photochemical reductive dissolution of iron(III)(hydr)oxides are depending on the pH-value. Iron(II) seems to be oxidised back to iron(III) preferably by hydrogen peroxide during the night. Positive correlations were received e.g. between the concentration of dissolved iron and the concentration of oxalate and between the percentage of iron(III) and the concentration of hydrogen peroxide. A negative correlation was found e.g. between the concentration of dissolved iron and the pH-value. The uncertainty of the whole process of sampling and analysis was investigated and the conformity of the results was satisfying considering the sometimes difficult conditions during a field campaign.

A new, simple, selective and sensitive spectrophotometric procedure for the on-site quantification of iron at nano-gram levels in atmospheric precipitations, i.e. rain as sample source is described. It is based on the color reaction of Fe3+ with SCN– ions in the presence of a cationic surfactant, i.e. cetylpyridinium chloride (CPC), in strong HCl solution, and subsequent extraction of the complex with N-octylacetamide into toluene or chloroform. The apparent molar absorptivity of the complex is 2.60 × 105 L mol–1 cm–1 at λmax = 480 nm at an enrichment factor (EF) of 10. The detection limit (causing higher absorbance than the sum of the blank absorbance (0.009) and 3 SD) is 5 ng mL–1 Fe. Ions commonly associated with iron did not interfere in the present method. The effect of analytical variables, i.e. amount and type of the reagents, acidity, solvent, temperature, dilution, etc., in the determination of iron are discussed. The validity of the present method is checked with GF-AAS. The method has been applied to the determination of iron at the ppb level in rain water samples.

In this study, the results of four different field experiments concerning the speciation of iron and the concentrations of some other chemical compounds in cloudwater samples are compared to one-another. Hydrogen peroxide concentrations were higher during campaigns, conducted at sites not much influenced by anthropogenic emissions as compared to those conducted at more polluted areas. In contrast, percentages of S(IV) in the cloudwater were lowest at the rural sites and highest at the sites polluted by human activities, indicating a consumption of hydrogen peroxide in the oxidation reaction with S(IV). The concentration of dissolved iron was observed to correlate with the percentage of S(IV), which may be an essential point for the reductive dissolution of oxidic iron compounds of the aerosol particles. As far as the speciation of the dissolved iron is concerned, it became obvious that the percentage of Fe(III) is anticorrelated to the concentration of dissolved iron. This clearly shows the important effect of the chemical and/or photo reductive ways of dissolving the iron(III)-compounds from the aerosol particles. However, a correlation between the pH-value and hydrogen peroxide was observed.

Rain is a main source for getting water to the ecosystem in the Indian continent. The factors i.e. operation of several heavy metal industries, coming of distant pollutants, high rain fall, etc. are agent for the precipitation of a high amount of the heavy metals in the eastern region of Madhya Pradesh state of India. The particulate matters and gases emitted are scavenged out with rain water for the distribution to the ecosystem. 216 event rain water samples were collected at three sites (representative of urban, industrial and remote): Raipur, Korba and Ambikapur of the country in the year 1995. 60 (30×2) event samples were collected at site Raipur during years, 1996–1997. The volume weighted mean concentration and fluxes distribution of most abundant heavy metals i.e. Mn, Fe, Cu, Zn, Hg, Pb are described. Their concentration level found in the rain water was: Pb≫Zn≫Cu≫Fe>Mn⋙Hg.

A new, sensitive, and selective method is described for the spectrophotometric determination of Ta(V). The method is based on the extraction of the Ta(V)-F -CV+ complex (CV+ = crystal violet cation) with a benzene solution of imidoyl derivatives (ID), i.e., N,N ' -diphenylbenzamidine (DPBA), N-hydroxy-N,N ' -diphenylbenzamidine, and N(2,5-dimethyl)phenyl-p-tolylimidoylphenylhydrazine, from sulfuric acid solution; DPBA was selected for detailed study. The molar absorptivities of the Ta(V)-F-CV+ -ID complexes in the benzene solution were in the range of (1.00-1.65) x 10(5) L/mol(.)cm at 600 nm. The limit of detection was 7 ng Ta/mL (which had an absorbance greater than that of the blank + 3 standard deviations). The optimization of the analytical variables, the composition of the complex, and the effect of diverse ions in the determination of Ta are discussed. The present method was applied to the determination of Ta in environmental samples, i.e,, soil, sediment, minerals, and alloys.