Simple method of determination of copper,mercury and lead in potable water with preliminary pre-concentration by total reflection X-ray fluorescence spectrometry

Total reflection X-ray fluorescence spectrometry and chemical pre-concentration procedures have been applied for the analysis of trace concentrations of copper, mercury, and lead in drinking water samples. A simple total reflection module has been used in X-ray measurements. The elements under investigation were pre-concentrated by complexation using a mixture of carbamates followed by solvent extraction with methyl isobutyl ketone. The preconcentration procedure was tested with the use of twice-distilled water samples and samples of mineral and tap water spiked with known additions of copper, mercury, and lead. The obtained recovery and precision values are presented. The minimum detection limits for the determination of these elements in mineral and tap water samples were found to be 40 ng l⁻¹, 60 ng l⁻¹, and 60 ng l⁻¹, respectively.     

Trace elements of coal,coal ashes and fly ashes by activation analysis with short-lived nuclides

On irradiation with neutrons, some of the interesting trace elements in coal, coal ash and fly ash produce short-lived nuclides which may be determined—together with some of the matrix elements—by activation analysis. This enables the characterization of samples. To find out the distribution of elements in the gaseous or aerosol exhaust of fossil-fired power plants, we simulated the combustion in a quartz apparatus containing a cold trap, using the combustion temperature (780 °C) employed for the standard ash determination. High Se values were found in the cold trap deposits from black coal from Poland. Halogens were also found in the deposits.     

Applicability of Hydrated Iron(III) Oxide and Dithiocarbamates as Colloid Collectors for Flotation Preconcentration of Manganese in Traces Before its ETAAS Determination

 The applicability of tetramethylenedithiocarbamate (TMDTC⁻) and hexamethylenedithiocarbamate (HMDTC⁻) for colloid flotation separation of manganese in traces from fresh (spring, well and tap) water was studied. The experimental conditions for the successful manganese separation and preconcentration before electrothermal atomic absorption spectrometric (ETAAS) determination were optimised. Higher enrichment of manganese was achieved when a larger amount of HMDTC⁻ is used. Applying iron(III) hexamethylenedithiocarbamate, Fe(HMDTC)₃, as a precipitate collector, manganese was determined at μg/L levels singly or simultaneously with lead and zinc in 1 L of water sample. The applicability of the proposed procedure have been verified by analyses of fresh water samples using the method of standard addition, as well as by comparing the results obtained by ETAAS with those obtained by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The detection limit of manganese using this method is 0.025 μg/L. Received August 30, 1999. Revision May 15, 2000     

Determination of trace Cd and Pb in natural waters by direct single drop microextraction combined with electrothermal atomic absorption spectrometry

A new method of direct single-drop microextraction combined with electrothermal atomic absorption spectrometry (ETAAS) is presented for the determination of trace Cd and Pb with dithizone (H₂DZ) as chelating reagent. Factors influencing the microextraction efficiency and determination, such as pH, microdrop volume, stirring rate, extraction time were evaluated. Under the optimized experimental conditions, the detection limits of the method are 2 and 90 pg mL⁻¹ for Cd and Pb, and the relative standards deviations for 0.5 ng mL⁻¹ Cd and 10 ng mL⁻¹ Pb are 11 and 12.8%. After 10 min of extraction, the enrichment factors for Cd and Pb are 118 and 90, respectively. The results for the determination of Cd and Pb in tap water, spring water, river water, pond water, lake water and spiked water samples demonstrate the accuracy, recovery and applicability of the method. An environmental water certified reference material (GSBZ 50009-88) was analyzed, and the determined values are in a good agreement with the certified values. Correspondence: Bin Hu, Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China     

Analysis of UV filters in tap water and other clean waters in Spain

The present paper describes the development of a method for the simultaneous determination of five hormonally active UV filters namely benzophenone-3 (BP3), 3-(4-methylbenzylidene) camphor (4MBC), 2-ethylhexyl 4-(dimethylamino) benzoate (OD-PABA), 2-ethylhexyl 4-methoxycinnamate (EHMC) and octocrylene (OC) by means of solid-phase extraction and gas chromatography–electron impact ionization–mass spectrometry. Under optimized conditions, this methodology achieved low method limits of detection (needed for clean waters, especially drinking water analysis), between 0.02 and 8.42 ng/L, and quantitative recovery rates higher than 73% in all cases. Inter- and intraday precision for all compounds were lower than 7% and 11%, respectively. The optimized methodology was applied to perform the first survey of UV absorbing compounds in tap water from the metropolitan area and the city of Barcelona (Catalonia, Spain). In addition, other types of clean water matrices (mineral bottled water, well water and tap water treated with an ion-exchange resin) were investigated as well. Results evidenced that all the UV filters investigated were detected in the water samples analyzed. The compounds most frequently found were EHMC and OC. Maximum concentrations reached in tap water were 290 (BP3), 35 (4MBC), 110 (OD-PABA), 260 (EHMC), and 170 ng/L (OC). This study constitutes the first evidence of the presence of UV filter residues in tap water in Europe.     

Characterization of serpentine: a potential nuclear shielding material

The use of serpentine as a potential nuclear shielding material necessitates a chemical quality control of the samples before its use in reactors. With this in view, characterization of these mineral samples was carried out using inductively coupled plasma atomic emission spectrometry (ICP-AES) and Instrumental neutron activation analysis (INAA) methods. The analytical results obtained by both ICP-AES and NAA techniques were found to be comparable. Na, Cr, Co, Zn, and Cu were found to be present in all samples of Indian origin while Ga, Ag, Ni, and Cd were found to below the limits of detection. A comparison on the detection limits of elements of interest was also carried out by both the analytical techniques and found to be in good agreement. An infrared spectroscopic investigation was also carried out on all the mineral samples. Bands at 3,689 and 3,648 cm⁻¹ were attributed to inner and outer hydroxyl stretching of Mg–OH, respectively. The weak and broad band centered around 3,416 cm⁻¹ was assigned due to the stretching vibrations of the adsorbed water molecules while three bands at 1076, 1022 and 968 cm⁻¹ were prescribed to the vibrations of the SiO₄ tetrahedra.     

Preparation and certification of JAC river water reference material for trace element analysis

 The Japan Society for Analytical Chemistry has recently issued a river water-certified reference material (CRM) for use in the ultratrace analysis of elements in fresh water. The river water CRM consists of a set of two (natural and spiked) 500-ml samples. The natural water is certified for Pb, Cr, As, Cu, Fe, Mn, Zn, B and Al at their sub-μg/l levels, while the spiked water is intended for use in the regulatory analysis of tap water and fresh water. Key words River water · Trace element analysis · Regulatory analysis · Reference materials     

Application of ICP-MS for Multielement Analysis in Small Sample Amoun ts of Pathological Thyroid Tissue

 As a result of the Chernobyl nuclear power plant accident in 1986, thyroid pathologies occurred among children in some regions of Belarus. Besides the irradiation of children’s thyroids by radioactive iodine and caesium nuclides, toxic elements from fallout are a direct risk to health. Inductively coupled plasma quadrupole-based mass spectrometry was used for multielement determination in small amounts (1–10 mg) of thyroid tissue samples obtained during thyroid operations in Minsk hospitals. The accuracy of the applied analytical technique for small biological sample amounts was checked using NIST Standard Reference Material oyster tissue (SRM 1566b) and by comparison with independent analytical methods, such as neutron activation analysis. Almost all essential elements as well as a number of toxic elements such as Cd, Pb, Hg, U etc. were determined in a multitude of human and animal thyroid tissues (up to 1 mg sample material) by quadrupole-based ICP-MS using micronebulization. In general, the thyroid tissue affected by pathology is characterized by higher calcium content. Some other elements, among them Fe, Mn, V, As, Cr, Ni, Pb, U, Ba, Sb, were also accumulated in such tissue. The results obtained will be used as initial material for further specific studies of the role of particular elements in thyroid pathology development. Received November 15, 1999. Revision March 15, 2000.     

CE method for analyzing Salmonella typhimurium in water samples

Salmonella typhimurium is commonly described as a food‐borne pathogen. However, natural and drinking water are known to be important sources for the transmission of this pathogen in developing and developed countries. The standard method to determine Salmonella is laborious and many false positives are detected. To solve this, the present work was focused on the development of a capillary zone electrophoresis method coupled to ultraviolet detection for determination of Salmonella typhimurium in water (mineral and tap water). Separations were performed in less than 11 minutes using 4.5 mM Tris (hydroxymethyl)‐aminomethane, 4.5 mM boric acid and 0.1 mM ethylene diamine tetraacetate (pH 8.4) with 0.1% v/v poly ethylene oxide as separation buffer. The precision of the method was evaluated in terms of repeatability obtaining a relative standard deviation of 10.5%. Using the proposed method Salmonella typhimurium could be separated from other bacteria that could be present in water such as Escherichia coli. Finally, the proposed methodology was applied to determine Salmonella typhimurium in tap and mineral water.     

Determination of copper, cadmium and lead in seawater and mineral water by flame atomic absorption spectrometry after coprecipitation with aluminum hydroxide

An aluminum hydroxide coprecipitation method for the determination of cadmium, copper and lead by flame atomic absorption spectrometry in aqueous solutions, seawater and mineral water samples has been investigated. The coprecipitation conditions, such as the effect of the pH, the amount of carrier element, the effect of possible matrix ions and the time were examined in detail for the studied elements. It was found that cadmium, copper and lead are co-precipitated quantitatively (≥95%) with aluminum hydroxide at pH 7 with low R.S.D. values of around 2 to 3%. Detection limits (38) were 6 ng ml⁻¹ for Cd, 3 ng ml⁻¹ for Cu and 16 ng ml⁻¹ for Pb. The method proposed was validated by the analysis of HPS 312205 seawater standard reference material and spiked mineral water samples.     

Trace-level determination of pharmaceutical residues by LC-MS/MS in natural and treated waters. A pilot-survey study

A pilot-survey study was performed by collecting samples (influent and effluent wastewaters, rivers and tap waters) from different locations in Europe (Spain, Belgium, Germany and Slovenia). A solid-phase extraction (SPE) followed by liquid chromatography–tandem mass spectrometry method was applied for the determination of pharmaceuticals (ibuprofen, naproxen, ketoprofen, diclofenac and clofibric acid). Method detection limits and method quantification limits were at the parts-per-trillion level (7.5–75 ng/L). The recovery rates of the SPE from deionized water and effluent wastewater samples spiked at 100- and 1,000-ng/L levels ranged from 87 to 95%. Identification criteria in compliance with the EU regulation for confirmatory methods of organic residues were applied. A detailed study of signal suppression evaluation for analysis of pharmaceutical residues in effluent wastewaters is presented.     

Stability of low levels of perchlorate in drinking water and natural water samples

Perchlorate ion (ClO₄⁻) is an environmental contaminant of growing concern due to its potential human health effects, impact on aquatic and land animals, and widespread occurrence throughout the United States. The determination of perchlorate cannot normally be carried out in the field. As such, water samples for perchlorate analysis are often shipped to a central laboratory, where they may be stored for a significant period before analysis. The stability of perchlorate ion in various types of commonly encountered water samples has not been generally examined—the effect of such storage is thus not known. In the present study, the long-term stability of perchlorate ion in deionized water, tap water, ground water, and surface water was examined. Sample sets containing approximately 1000, 100, 1.0, and 0.5 μg l⁻¹ perchlorate ion in deionized water and also in local tap water were formulated. These samples were analyzed by ion chromatography for perchlorate ion concentration against freshly prepared standards every 24 h for the first 7 days, biweekly for the next 4 weeks, and periodically after that for a total of 400 or 610 days for the two lowest concentrations and a total of 428 or 638 days for the high concentrations. Ground and surface water samples containing perchlorate were collected, held and analyzed for perchlorate concentration periodically over at least 360 days. All samples except for the surface water samples were found to be stable for the duration of the study, allowing for holding times of at least 300 days for ground water samples and at least 90 days for surface water samples.     

Determination of rare earth elements in hot spring water and crater lake water samples by neutron activation analysis incorporating coprecipitation process using aluminium as a collector

Hot spring water and crater lake water samples were analyzed for their rare earth elements: (REE's) by neutron activation method, which, in the irradiation, sample preparation, incorporated a coprecipitation process in which aluminium was used as a collector. Ten REE's, La, Ce, Sm, Eu, Gd, Tb, Dy, Tm, Yb and Lu, were consequently detected and determined at the ppb level with satisfactory precision. It was shown that the aluminium coprecipitation is effective in enhancing concentrations of the REE's and reducing the amounts of interfering nuclides before neutron irradiation.     

Determination of sodium and chlorine in pure water by neutron activation analysis

Neutron activation analysis was applied to determine sodium and chlorine in high purity water samples. After irradiation of the sample,³⁸Cl was purified from⁸²Br and other nuclides by carbon tetrachloride extraction and silver chloride precipitation, and²⁴Na was separated from other alkali elements and other nuclides by adsorption of²⁴Na on HAP. The activities of both elements were measured by conventional G.M. counter. The contamination of the elements from container walls during neutron irradiation and the interference with³⁸Ar(n, p)³⁸Cl reaction on argon dissolved in water were also examined. Water samples containing 3 ppb of chlorine could not be determined accurately, owing to the above mentioned interfering reaction.     

Development of a selective molecularly imprinted polymer-based solid-phase extraction for indomethacin from water samples

A selective molecularly imprinted solid-phase extraction (MISPE) for indomethacin (IDM) from water samples was developed. Using IDM as template molecule, acrylamide (AM) or methacrylic acid (MAA) as functional monomer, ethylene dimethacrylate (EDMA) as crosslinker, and bulk or suspension polymerization as the synthetic method, three molecularly imprinted polymers (MIPs) were synthesized and characterized with a rebinding experiment. It was found that the MIP of AM-EDMA produced by bulk polymerization showed the highest binding capacity for IDM, and so it was chosen for subsequent experiments, such as those testing the selectivity and recognition binding sites. Scatchard analysis revealed that at least two kinds of binding sites formed in the MIP, with the dissociation constants of 7.8 μmol L⁻¹ and 127.2 μmol L⁻¹, respectively. Besides IDM, three structurally related compounds — acemetacin, oxaprozin and ibuprofen — were employed for selectivity tests. It was observed that the MIP exhibited the highest selective rebinding to IDM. Accordingly, the MIP was used as a solid-phase extraction sorbent for the extraction and enrichment of IDM in water samples. The extraction conditions of the MISPE column for IDM were optimized to be: chloroform or water as loading solvent, chloroform with 20% acetonitrile as washing solution, and methanol as eluting solvent. Water samples with or without spiking were extracted by the MISPE column and analyzed by HPLC. No detectable IDM was observed in tap water and the content of IDM in a river water sample was found to be 1.8 ng mL⁻¹. The extraction efficiencies of the MISPE column for IDM in spiked tap and river water were acceptable (87.2% and 83.5%, respectively), demonstrating the feasibility of the prepared MIP for IDM extraction. Figure Molecularly imprinted polymer-based solid-phase extraction for indomethacin     

Preliminary results of a quick,simple method of detecting antimony in water samples

Preliminary results of development of a direct and fast method of determination of antimony in samples of tap water using GFAAS are presented. The found levels of antimony were lower than permitted for human consumption. A mixture of Pd and Mg(NO₃)₂ (concentrations in the injected solution: 8.6 μg mL⁻¹ and 5.8 μg mL⁻¹ respectively) was used as the chemical modifier. The pyrolysis and atomization temperatures were 1000 and 1700°C, respectively and the mean analytical recovery 98.2%.      

Radiochemical activation analysis of arsenic,selenium and antimony in biological samples

A method for the neutron activation analysis of arsenic, selenium and antimony has been developed. A radiochemical separation is performed by distillation followed by precipitation of the individual elements. Selenium and arsenic are precipitated by reduction to the elemental form while antimony is precipitated as sulfide. The chemical yields and detection limits using 0.5 g samples are the following: As 90–100%, 0.4 ppb, Se 80–100%, 8 ppb and Sb 50–70%, 0.2 ppb. Results from the analysis of nine international biological standard samples are given.     

Elemental composition of drinking water supplies in three states in Southeastern Nigeria

The levels of some trace elements; Co, Mn, Cu, Zn, Cr, Cd, Pb, Fe, Hg, Se, As, Ni and minor elements; Na, K, Ca and Mg were determined in public drinking water supplies (public taps and groundwaters) in three states in Southeastern Nigeria using energy dispersive X-ray fluorescence spectrometry (EDXRF) and flame atomic absorption spectrometry (FAAS). The mean levels of most of the trace elements in the groundwater samples were below the World Health Organization (WHO) drinking water quality limits, the only exception being Hg whose mean value of 3.69 μg/l exceeded the WHO limit of 1.0 μg/l. Violations of the WHO limits were also observed for Fe, Zn, Se and Pb in some of the groundwater samples. In the public tap samples only Hg violated the WHO limit.     

Application of Inductively Coupled Plasma Spectrometric Techniques and Multivariate Statistical Analysis in the Hydrogeochemical Profiling of Caves—Case Study Cloșani,Romania

The aim of the study was to develop the hydrogeochemical profiling of caves based on the elemental composition of water and silty soil samples and a multivariate statistical analysis. Major and trace elements, including rare earths, were determined in the water and soil samples. The general characteristics of water, anions content, inorganic and organic carbon fractions and nitrogen species (NO₃⁻ and NH₄⁺) were also considered. The ANOVA—principal component analysis (PCA) and two-way joining analysis were applied on samples collected from Cloșani Cave, Romania. The ANOVA-PCA revealed that the hydrogeochemical characteristics of Ca²⁺-HCO₃⁻ water facies were described by five factors, the strongest being associated with water-carbonate rock interactions and the occurrence of Ca, Mg and HCO₃⁻ (43.4%). Although organic carbon fractions have a lower influence (20.1%) than inorganic ones on water characteristics, they are involved in the chemical processes of nitrogen and of the elements involved in redox processes (Fe, Mn, Cr and Sn). The seasonal variability of water characteristics, especially during the spring, was observed. The variability of silty soil samples was described by four principal components, the strongest influence being attributed to rare earth elements (52.2%). The ANOVA-PCA provided deeper information compared to Gibbs and Piper diagrams and the correlation analysis.     

Determination of 22 elements in geological samples by instrumental neutron activation analysis

An instrumental neutron activation analysis (INAA) method has been developed for multi-element determination in geological samples. The INAA method consists of irradiation of samples for 90 sec at a flux of 1.0·10¹² n·cm⁻²·sec⁻¹ and determination of 12 elements by using their short-lived nuclides. Samples have been re-irradiated for 3 hrs for measuring concentrations of another 10 elements. Precision and accuracy of the INAA method have been evaluated by analysing samples and USGS standard reference materials. Precision and accuracy are within±15% and ±10%, respectively.