An off-line automated preconcentration system with ethylenediaminetriacetate chelating resin for the determination of trace metals in seawater by high-resolution inductively coupled plasma mass spectrometry

A novel automated off-line preconcentration system for trace metals (Al, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb) in seawater was developed by improving a commercially available solid-phase extraction system SPE-100 (Hiranuma Sangyo). The utilized chelating resin was NOBIAS Chelate-PA1 (Hitachi High-Technologies) with ethylenediaminetriacetic acid and iminodiacetic acid functional groups. Parts of the 8-way valve made of alumina and zirconia in the original SPE-100 system were replaced with parts made of polychlorotrifluoroethylene in order to reduce contamination of trace metals. The eluent pass was altered for the back flush elution of trace metals. We optimized the cleaning procedures for the chelating resin column and flow lines of the preconcentration system, and developed a preconcentration procedure, which required less labor and led to a superior performance compared to manual preconcentration (Sohrin et al. [5]). The nine trace metals were simultaneously and quantitatively preconcentrated from ∼120 g of seawater, eluted with ∼15 g of 1 M HNO₃, and determined by HR-ICP-MS using the calibration curve method. The single-step preconcentration removed more than 99.998% of Na, K, Mg, Ca, and Sr from seawater. The procedural blanks and detection limits were lower than the lowest concentrations in seawater for Mn, Ni, Cu, and Pb, while they were as low as the lowest concentrations in seawater for Al, Fe, Co, Zn, and Cd. The accuracy and precision of this method were confirmed by the analysis of reference seawater samples (CASS-5, NASS-5, GEOTRACES GS, and GD) and seawater samples for vertical distribution in the western North Pacific Ocean.     

Intercomparison of five methods for the determination of trace metals in sea water

Trace elements (Mn, Fe, Co, Zn, Ni, Cu and Cr) were preconcentrated from sea water by retention on Chelex-100 resin, APDC/8-quinolinol complexation followed by extraction with 4-methyl-2-pentanon or Freon-113, or coprecipitation with Mg(OH)₂ or Fe(OH)₂. After consideratin of analytical blanks, extraction efficiency, precision preconcentration factor, and suitability for operation on board ship, the best results were obtained by preconcentrating Mn, Fe, Co, Zn, Ni and Cu on Chelex-100 resin and coprecipitation of chromium(III) and (VI) with Fe(OH)₂. Graphite-furnace atomic absorption spectrometry and inductively-coupled plasma atomic emission spectrometry were used for the final measurements. The accuracy of the method was tested by using the reference sea water sample NASS-1.     

Molybdenum(VI) Oxide-Modified Silica Gel as a Novel Sorbent for the Simultaneous Solid-Phase Extraction of Eight Metals with Determination by Flame Atomic Absorption Spectrometry

A silica-based inorganic sorbent was synthesized by the thermal decomposition of ammonium heptamolybdate on silica and applied for the preconcentration and simultaneous determination of Cd, Co, Cr, Cu, Fe, Mn, Ni, and Pb in river water samples using a column system with flame atomic absorption spectrometry. Attenuated total reflection-Fourier transformation infrared spectroscopy, scanning electron microscopy, and electron dispersive spectroscopy were used for sorbent characterization. The effects of pH, sample volume, eluent type, eluent concentration, eluent volume, sample flow rate, and matrix ions (Al, Bi, Ca, Mg, and Zn) on the recovery of the metals in model solutions were investigated. The adsorption capacities (µmol g^?1) of SiO₂-MoO₃ were 88.96 (Cd), 169.69 (Co), 153.85 (Cr), 188.88 (Cu), 179.05 (Fe), 163.81 (Mn), 136.31 (Ni), and 38.61 (Pb). The detection limits of the method were 9.09, 10.82, 10.77, 49.57, 31.64, 6.40, 8.86, 19.15?µg L^?1 for Cd, Co, Cr, Cu, Fe, Mn, Ni, and Pb, respectively, with a preconcentration factor of 25. The developed method was used for the determination of the target metals in real samples and the recoveries for spiked samples were found to be from 91.2% to 102.9%.     

Immobilization of 8-hydroxyquinoline onto silicone tubing for the determination of trace elements in seawater using flow injection ICP-MS

A rapid and simple on-line method is described for the preconcentration of Mn, Co, Ni, Cu, Zn, Cd and Pb from sea water using 8-hydroxyquinoline immobilized onto silicone tubing (Sil-8-HQ) via the Mannich reaction. Recoveries between 35 and 95% and limits of detection in the ppt range were obtained using a 2 m long Sil-8-HQ tube with a sample flow rate of 1.0 ml min(-1). A tube could be subjected to sample loading and elution cycles over 200 times. The capacity was 1.5 and 1.3 mug cm(-2) for Cu and Mn, respectively. Cu, Cd, Co, Pb, Mn, Zn and Ni were determined in coastal and open ocean seawater using flow injection inductively coupled plasma mass spectrometry (FI-ICP-MS). Good agreement with certified values for the certified reference materials NASS-4 and CASS-3 was demonstrated when quantitation was undertaken by the method of additions.     

Multielement determination of trace metals in seawater by ICP-MS with aid of down-sized chelating resin-packed minicolumn for preconcentration

The multielement determination of trace metals in seawater was carried out by inductively coupled plasma mass spectrometry (ICP-MS) with aid of a down-sized chelating resin-packed minicolumn for preconcentration. The down-sized chelating resin-packed minicolumn was constructed with two syringe filters (DISMIC 13HP and Millex-LH) and an iminodiacetate chelating resin (Chelex 100, 200-400 mesh), with which trace metals in 50 mL of original seawater sample were concentrated into 0.50 mL of 2 M nitric acid, and then 100-fold preconcentration of trace metals was achieved. Then, 0.50 mL analysis solution was subjected to the multielement determination by ICP-MS equipped with a MicroMist nebulizer for micro-sampling introduction. The preconcentration and elution parameters such as the sample-loading flow rate, the amount of 1 M ammonium acetate for elimination of matrix elements, and the amount of 2 M nitric acid for eluting trace metals were optimized to obtain good recoveries and analytical detection limits for trace metals. The analytical results for V, Mn, Co, Ni, Cu, Zn, Mo, Cd, Pb, and U in three kinds of seawater certified reference materials (CRMs; CASS-3, NASS-4, and NASS-5) agreed well with their certified values. The observed values of rare earth elements (REEs) in the above seawater CRMs were also consistent with the reference values. Therefore, the compiled reference values for the concentrations of REEs in CASS-3, NASS-4, and NASS-5 were proposed based on the observed values and reference data for REEs in these CRMs.     

Trace metal accumulation in tissues of sole (Solea senegalensis) and the relationships with the abiotic environment

The distribution patterns and the organ-specific accumulation trends of 10 trace metals (iron, manganese, zinc, copper, chromium, nickel, cobalt, lead, cadmium and silver) and 4 major elements (sodium, potassium, calcium and magnesium) in 10 different tissues (heart, muscle, kidney, stomach, intestine, liver, gill, gonads, white skin and dark skin) of a benthic fish species (Solea senegalensis) from a densely populated coastal area affected by anthropogenic activities, the Bay of Cadiz (SW Spain), have been investigated. High variability of metal concentrations among tissues were found for Ca, Fe, Zn, Cu, Pb and Ag. Factor analysis was applied to study this variability. Five principal components were found explaining the 92.95% of the total variance and similarities in behavioural patterns of bioaccumulation were described. They associated Mg, Cr, Ni and Mn to intestine and stomach tissues (PC1), Ag, Cu and Cd to liver (PC2), Zn, K and Co to gonads (PC3), Na, Fe and Pb to gill, heart and kidney tissues (PC4) and Ca, Pb and Mn to gill and dark skin (PC5). The metallic concentration in the sediment and water was also studied. The pollution in this area was found moderate with outstanding values of Zn, Cu and Pb (average values of 139, 50.4 and 75.6?mg?kg^?1, respectively) in sediment and dissolved Cu (average value of 2.5?µg?L^?1). Metal bioconcentration trends followed the order Zn?>?Cu?>?Cd?>?Pb for dissolved metals in seawater, Cu?>?Zn?>?Cd?>?Pb?≈?Mn?>?Fe?≈?Ni?≈?Co for metals associated to particulate matter and Zn?≈?Cu?>?Cd?>?Mn?>?Co?≈?Fe?>?Ni?≈?Pb?>?Cr for metals in the sediment. Higher values were found for copper in liver, zinc in gonads and lead in gill, showing the relationship between biotic and abiotic environment. In addition, Cd bioconcentration factors were found high in liver and gill showing the sensitivity of sole to this metal even at low concentrations.     

Determination of trace metals in seawater by an automated flow injection ion chromatograph pretreatment system with ICPMS

A novel flow injection ion chromatograph (FI-IC) system has been developed to fully automate pretreatment procedures for multi-elemental analysis of trace metals in seawater by inductively coupled plasma mass spectrometer (ICPMS). By combining 10-port, 2 position and 3-way valves in the FI-IC manifold, the system effectively increase sample throughput by simultaneously processing three seawater samples online for: sample loading, injection, buffering, preconcentration, matrix removal, metal elution, and sample collection. Forty-two seawater samples can be continuously processed without any manual handing. Each sample pretreatment takes about 10 min by consuming 25 mL of seawater and producing 5 mL of processed concentrated samples for multi-elemental offline analysis by ICPMS. The offline analysis improve analytical precision and significantly increase total numbers of isotopes determined by ICPMS, which include the metals Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Ti, V, and Zn. The blank value and detection limits of trace metals using the system with ICPMS analysis all range from 0.1 to 10 parts per trillion (ppt), except Al, Fe, and Zn. The accuracy of the pretreatment system was validated by measuring open-ocean and coastal reference seawater, NASS-5 and CASS-4. Using the system with ICPMS analysis, we have obtained reliable trace metal concentrations in the water columns of the South China Sea. Possessing the features of full automation, high throughput, low blank, and low reagent volume used, the system automates and simplifies rigorous and complicated pretreatment procedures for multi-elemental analysis of trace metals in seawater and effectively enhances analytical capacity for trace metal analysis in environmental and seawater samples.     

Simultaneous determination of twelve trace elements in estuarine and sea water using pre-irradiation chromatography

A procedure is described for the preconcentration of 100 ml of estuarine and seawater into a solid sample using Chelex-100 resin. This solid sample weighs less than half a gram and contains the transition metals and many other elements of interest, but is essentially free from the alkali metals, the alkaline earth metals, and the halogens. The concentrations of Co, Cr, Cu, Fe, Mn, Mo, Ni, Sc, Th, U, V and Zn have been determined in seawater when this procedure was coupled to neutron activation analysis.     

Triton X-100微乳液体系中铁的萃取与分离

近年来 ,在以表面活性剂分子有序组合油包水 (W/O)微乳液体系中进行萃取分离已引起人们的重视 [1～ 3] .本文根据微乳液体系较相应胶束有更低的表面张力和更高增溶量的特性 ,首次利用非离子型水包油 (O/W)壬基酚聚氧乙烯醚(Triton X- 1 0 0 )微乳液在无机盐硫酸铵的存在下萃取分离铁 ,与传统的有机溶剂萃取分离方法比较 ,此法具有不挥发、无毒、快速和操作简单等特点 ;与高聚物水溶液体系萃取 ,有相同的萃取效果 ,但药品用量相对减少 .GBC932 AA原子吸收分光光度计 (澳大利亚 ) ;p Hs- 2 5酸度计 (上海雷磁仪器厂 ) .铝试剂为质量分数 …     

A solid phase extraction using a chelate resin immobilizing carboxymethylated pentaethylenehexamine for separation and preconcentration of trace elements in water samples

A chelate resin immobilizing carboxymethylated pentaethylenehexamine (CM-PEHA resin) was prepared, and the potential for the separation and preconcentration of trace elements in water samples was evaluated through the adsorption/elution test for 62 elements. The CM-PEHA resin could quantitatively recover various elements, including Ag, Cd, Co, Cu, Fe, Ni, Pb, Ti, U, and Zn, and rare earth elements over a wide pH range, and also Mn at pH above 5 and V and Mo at pH below 7. This resin could also effectively remove major elements, such as alkali and alkaline earth elements, under acidic and neutral conditions. Solid phase extraction using the CM-PEHA resin was applicable to the determination of 10 trace elements, Cd, Co, Cu, Fe, Mn, Mo, Ni, Pb, V, and Zn, in certified reference materials (EnviroMAT EU-L-1 wastewater and ES-L-1 ground water) and treated wastewater and all elements except for Mn in surface seawater using inductively coupled plasma atomic emission spectrometry. The detection limits, defined as 3 times the standard deviation for the procedural blank using 500 mL of purified water (50-fold preconcentration, n = 8), ranged from 0.003 μg L⁻¹ (Mn) to 0.28 μg L⁻¹ (Zn) as the concentration in 500 mL of solution.     

Multielemental Analysis of Human Serum by Dynamic Reaction Cell–Inductively Coupled Plasma Mass Spectrometry

The selection of the most suitable dilution methods for determination of trace elements in human serum using inductively coupled plasma mass spectrometry is reported. The trace elements were Al, V, Cr, Fe, Mn, Co, Cu, Zn, As, Cd, Sn, Tl, and Pb. The performance of various dilution methods was assessed by precision, linearity, detection limits, quantification limits, fortified recoveries, and the analysis of reference materials. The results demonstrate that diluted solution containing only nitric acid is most suitable for As, Cr, Mn, and Co in serum. Dilute solutions containing nitric acid and Triton X-100 were most appropriate for Cu, Zn, Cd, and Tl. The optimum conditions for Al, V, Mn, Fe, Cr, Co, Sn, and Pb used tetra-n-butylammonium hydroxide, Triton X-100, and ethylenediamine tetraacetic acid.     

Co-precipitative pre-concentration with sodium diethyldithiocarbamate and ICP-AES determination of Se, Cu, Pb, Zn, Fe, Co, Ni, Mn, Cr and Cd in water

Sodium diethyldithiocarbamate in the presence of a weak oxidizing agent is used as a co-precipitative agent for the pre-concentration of Se, Cu, Pb, Zn, Fe, Co, Ni, Mn, Cr and Cd. A procedure was developed for ICP-AES determination of these elements after pre-concentration in river and waste water (an enrichment factor of 40). The recovery of all the elements tested for was more than 98%. The limits of determination (mg l⁻¹) (10 S.D. blank) are 0.001 (Cu, Co, Cr, Mn), 0.0007 (Zn, Cd), 0.003 (Se), 0.004 (Fe), 0.007 (Ni), and 0.01 (Pb).     

Extraction system for flame atomic absorption spectrometric analysis of high-purity bismuth compounds

Two new ligands, 2-(2-benzoxazolyl)cyanoacetaldehyde and 2-(2-benzoxazolyl)malonaldehyde are proposed for extractive separation and preconcentration. The extraction behaviour of Ag, Bi, Cd, Co, Cu, Fe, Mn, Mo, Ni, Pb, Pd, Pt, Sb and Zn with respect to pH, salt concentration and the presence of various masking agents was studied. A simple extraction procedure for the analysis of high-purity bismuth compounds was developed.     

Pulverized Banana Peel as an Economical Sorbent for the Preconcentration of Metals

A procedure for the determination of trace levels of Cd, Co, Cr, Fe, Mn, Ni, and Pb by flame atomic absorption spectrometry using a column preconcentration system is described in which the metals were adsorbed on pulverized banana peel, an economically and environmentally acceptable sorbent. In the optimization procedure, five variables (sample pH, mass of biosorbent, type of eluent, sample flow rate, and volume) were optimized and the capacity of the biosorbent was established. Under the optimized conditions, the detection limits of the method were 2.4, 27.0, 49.4, 31.1, 6.7, 29.6, and 46.2 µg L^?1 for Cd, Co, Cr, Fe, Mn, Ni, and Pb, respectively. The precision, expressed as relative standard deviation, was less than 4% based on twelve measurements. The recoveries were 81.1% (Cd), 91.4% (Co), 87.2% (Cr), 90.1% (Fe), 88.0% (Mn), 94.1% (Ni), and 93.2% (Pb) under the optimum conditions (pH; 9, sample flow rate; 3 mL min^?1, mass of biosorbent; 200 mg; eluent; 1 mol L^?1 nitric acid, preconcentration factor; 10). The sorption capacity of pulverized banana peel was 15.12, 28.85, 32.70, 30.44, 30.94, 28.97, and 8.21 µmol per gram of adsorbent for Cd, Co, Cr, Fe, Mn, Ni, and Pb, respectively.     

Pre-concentration of trace metals from sea-water for determination by graphite-furnace atomic-absorption spectrometry

Determination of Cd, Zn, Pb, Cu, Fe, Mn, Co, Cr and Ni in coastal sea-water by graphite-furnace atomic-absorption spectrometry after preconcentration by solvent extraction and use of a chelating ion-exchange resin is described. Following the extraction of the pyrrolidine-N-carbodithioate and oxinate complexes into methyl isobutyl ketone, the trace metals are further preconcentrated by back-extraction into 1.5M nitric acid. Preconcentration on the chelating resin is effected by a combined column and batch technique, allowing greater preconcentration factors to be obtained. Provided samples are appropriately treated to release non-labile metal species prior to preconcentration, both methods yield comparable analytical results with respect to the mean concentrations determined as well as to mean relative standard deviations. Control and treatment of the analytical blank is also described.     

Chelate von β-dicarbonylverbindungen und ihren derivaten: Teil XXXVI. Die extraktionsphotometrische bestimmung von cadmium mit thiodibenzoylmethan im vergleich mit anderen spezialreagenzien

Thiodibenzoylmethane is a suitable reagent for the extraction and photometric determination of traces of cadmium. There is no interference from 10000-fold amounts of alkaline and alkaline earth metals, B, Al, Ga, In, Mn, Fe, Cr, and from 1000-fold amounts of As, Sb, Sn, Pb, Bi, Cu, Co, Ni, Pd; Ag, Hg, Tl and Zn are tolerated up to a 100-fold excess. The proposed method is compared with various other possibilities for cadmium determinations.     

Comparison of metal analysis in sediments using EDXRF and ICP-OES with the HCl and Tessie extraction methods

The work presents an investigation on metal availability in sediments during 13 months using the dispersive-energy X-ray fluorescence (EDXRF) and atomic emission spectrometry with induced argon plasma (ICP-OES) techniques and single extraction (0.1 mol l⁻¹ HCl) and Tessie’s sequential speciation methods. The EDXRF technique could yield essentially the same profile as ICP-OES for the seasonal variation of metals in sediments, but in a more practical way. The sequential extraction procedure (SEP) was more efficient in metal dissolution than single extraction. The Pb, Ni, Al, Cr, and Fe elements were less efficiently extracted with single extraction in relation to sequential extraction. For Co both methodologies were equivalent, but for Cu and Mn the extraction was higher with single extraction. Single extraction does not mobilize Pb, Ni, Al, Cr, and Fe adsorbed on oxides and bound to organic matter. However for Cu and Mn, not only extracted these metals from the four fractions, but it also dissolved part of the fifth fraction (residual). Principal Component Analysis discriminated seasonal variations in the content of several metals, mainly Fe, Co, Ni, and Zn. The mobility of metallic ions in the sediments is conditioned to the seasonal flow of organic and inorganic material coming from the river or by the erosion of adjacent soils.     

Determination of Cd, Co, Cr, Cu, Fe, Mn, Ni and Pb in natural waters, alkali and alkaline earth salts by electrothermal atomic absorption spectrometry after preconcentration by column solid phase extraction

Methods are described for the determination of trace and ultra trace amounts of Cd, Co, Cr, Cu, Fe, Mn, Ni and Pb in natural waters, alkali and alkaline earth salts. Separation and preconcentration of trace metals is achieved by a column solid phase extraction procedure using silica gel modified with derivatives of dithiocarbamates — Na-DDTC (sodium diethyldithio-carbamate and HMDTC (ammonium hexamethylene-dithiocarbamate) as column packing material. The influence of the sorbent preparation procedure on the degree of sorption of the trace analytes is examined for different pH values of the sample solution. Isobutylmethyl ketone (IBMK) is proposed as an effective eluent for quantitative elution of retained metal ions. Optimal instrumental parameters for ETAAS determination of preconcentrated elements in organic eluate are presented. Practical application of sorbents in analysis of natural waters and alkali and alkaline earth salts is demonstrated. Proposed preconcentration procedure combined with ETAAS determination of trace analytes allows the determination of 0.04 g l^–1 Cd, 0.1 g l^–1 Cr, Cu, and Mn and 0.3 g l^–1 Co, Fe, Ni and Pb in natural waters and 1.10^–7% Cd, 3.10^–7% Cr and Mn, 7.10^–7% Co, Ni and Pb and 2.10^–6% Cu and Fe in alkali and alkaline earth salts.     

Simultaneous on-line preconcentration and determination of trace metals in environmental samples by flow injection combined with inductively coupled plasma mass spectrometry using a nanometer-sized alumina packed micro-column

A flow injection (FI) on-line preconcentration procedure by using a nanometer-sized alumina packed micro-column coupled to inductively coupled plasma mass spectrometry (ICP-MS) was described for simultaneous determination of trace metals (V, Cr, Mn, Co, Ni, Cu, Zn, Cd and Pb) in the environmental samples. The effects of pH value, sample flow rate, preconcentration time, and interfering ions on the preconcentration of analytes have been investigated. Under the optimized operating conditions, the adsorption capacity of the nanometer-sized alumina for V, Cr, Mn, Co, Ni, Cu, Zn, Cd and Pb were found to be 11.7, 13.6, 15.7, 9.5, 12.2, 13.3, 17.1, 17.7 and 17.5 mg g⁻¹, respectively. With 60 s preconcentration time and 60 s elution time, an enrichment factor of 5 and the sampling frequency of 15 h⁻¹ were obtained. The proposed method has been applied to the determination of trace metals in environmental certified reference materials and natural water samples with satisfactory results.     

Chelate von β-dicarbonylverbindungen und ihren derivaten: Teil XXXIV. Die verwendung von thiodibenzoylmethan zur extraktionsphotometrischen bestimmung von thallium- und quecksilberspuren

Thiodibenzoylmethane is a very suitable ligand for the extraction and spectrophotornetric determination of traces of mercury (0.05–0.5 μmol) and thallium (0.1–1.0 μmol). Both methods are rapid and can be made highly selective by means of masking reagents. The influence of numerous other metals, e.g. Ga, In, Pb, Sn, As, Sb, Bi, Cd, Zn, Pd, Ag, Cu, Ni, Co, Fe, Mn, Cr, alkali and alkaline earth metals, and also of anions as fluoride, chloride, bromide, iodide, thiocyanate, sulphide, sulphate, nitrate, EDTA and thioglycolic acid was examined.