Synthesis of novel chitosan resin derivatized with serine moiety for the column collection/concentration of uranium and the determination of uranium by ICP-MS

A chitosan resin derivatized with serine moiety (serine-type chitosan) was newly developed by using the cross-linked chitosan as a base material. The adsorption behavior of trace amounts of metal ions on the serine-type chitosan resin was systematically examined by packing it in a mini-column, passing a metal solution through it and measuring metal ions in the effluent by ICP-MS. The resin could adsorb a number of metal cations at pH from neutral to alkaline region, and several oxoanionic metals at acidic pH region by an anion exchange mechanism. Uranium and Cu could be adsorbed selectively at pH from acidic to alkaline region by a chelating mechanism; U could be adsorbed quantitatively even at pH 3–4. Uranium adsorbed on the resin was easily eluted with 1 M nitric acid: the preconcentration (5-, 10-, 50- and 100-fold) of U was possible. The column treatment method was used prior to the ICP-MS measurement of U in natural river, sea and tap waters; R.S.D. were 2.63, 1.13 and 1.37%, respectively. Uranium in tap water could be determined by 10-fold preconcentration: analytical result was 1.46±0.02 ppt. The resin also was applied to the recovery of U in sea water: the recovery tests for artificial and natural sea water were 97.1 and 93.0%, respectively.     

Synthesis of cross-linked chitosan functionalized with threonine moiety and its application to on-line collection/concentration and determination of Mo, V and Cu

A novel chitosan-based resin functionalized with threonine moiety was synthesized, and applied to the collection/concentration of Mo, V and Cu in environmental water samples, followed by their determination using inductively coupled plasma-atomic emission spectrometer (ICP-AES). The synthesized resin, cross-linked chitosan-threonine (CCTS-Thr), showed good adsorption behavior toward trace amounts of Mo, V and Cu in a wide pH range. The adsorbed elements can be easily eluted using 2molL(-1) of nitric acid, and their recoveries were found to be 90-100%. The CCTS-Thr was packed in a mini-column, which was then installed in a computer-controlled auto-pretreatment system (Auto-Pret System) for on-line trace elements collection and determination by ICP-AES. Experimental parameters related to the improvement of sensitivity and reproducibility were optimized. The limits of detection (LODs) for target metals were found to be in sub-ppb level. The proposed method with CCTS-Thr resin was successfully applied to the determination of Mo, V and Cu in environmental water samples. The recovery test showed that common matrices which exist in environmental water samples did not interfere with the determination.     

Synthesis of cross-linked chitosan possessing N-methyl-d-glucamine moiety (CCTS-NMDG) for adsorption/concentration of boron in water samples and its accurate measurement by ICP-MS and ICP-AES

A chitosan resin derivatized with N-methyl-d-glucamine (CCTS-NMDG) was synthesized by using a cross-linked chitosan (CCTS) as base material. The N-methyl-d-glucamine (NMDG) moiety was attached to the amino group of CCTS through the arm of chloromethyloxirane. The adsorption behavior of 59 elements on the synthesized resin was systematically examined by using the resin packed in a mini-column, passing water samples through it and measuring the adsorbed elements in eluates by ICP-MS. The CCTS-NMDG resin shows high ability in boron sorption with the capacity of 0.61 mmol ml⁻¹ (= 2.1 mmol g⁻¹). The sorption kinetics of this resin was faster than that of the commercially available resins. Other advantages of the synthesized resin are: (1) quantitative collection of boron at neutral pH regions; (2) complete removal of large amounts of matrices; (3) no loss of efficiency over prolonged usage; (4) effective collection of boron in wide range concentration using a mini column containing 1 ml resin; (5) complete elution of boron with 1 mol l⁻¹ nitric acid. The resin was applied to the collection/concentration of boron in water samples. Boron in tap water and river water was found to be in the range of 6-8 μg l⁻¹. The limit of detection (LOD) of boron after pretreatment with CCTS-NMDG resin and measurement by ICP-MS was 0.07 μg l⁻¹ and the limit of quantification (LOQ) was 0.14 μg l⁻¹ when the volume of each sample and eluent was 10 ml.     

Synthesis of chitosan resin possessing a phenylarsonic acid moiety for collection/concentration of uranium and its determination by ICP-AES

A chitosan resin possessing a phenylarsonic acid moiety (phenylarsonic acid type chitosan resin) was developed for the collection and concentration of trace uranium prior to inductively coupled plasma (ICP) atomic emission spectrometry (AES) measurement. The adsorption behavior of 52 elements was systematically examined by packing it in a minicolumn and measuring the elements in the effluent by ICP mass spectrometry. The resin could adsorb several cationic species by a chelating mechanism, and several oxo acids, such as Ti(IV), V(V), Mo(VI), and W(VI), by an anion-exchange mechanism and/or a chelating mechanism. Especially, U(VI) could be adsorbed almost 100% over a wide pH region from pH 4 to 8. Uranium adsorbed was easily eluted with 1 M nitric acid (10 mL), and the 25-fold preconcentration of uranium was achieved by using a proposed column procedure, which could be applied to the determination of trace uranium in seawater by ICP-AES. The limit of detection was 0.1 ng mL⁻¹ for measurement by ICP-AES coupled with 25-fold column preconcentration.     

Functionalization of chitosan with 3-nitro-4-amino benzoic acid moiety and its application to the collection/concentration of molybdenum in environmental water samples

A chitosan resin functionalized with 3-nitro-4-amino benzoic acid moiety (CCTS-NABA resin) was newly synthesized for the collection/concentration of trace molybdenum by using cross-linked chitosan (CCTS) as base material. The carboxyl group of the moiety was chemically attached to amino group of cross-linked chitosan through amide bond formation. The adsorption behavior of molybdenum as well as other 60 elements on the resin was examined by passing the sample solutions through a mini-column packed with the resin. After the elution of the elements collected on the resin with 1 M HNO₃, the eluates were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) and atomic emission spectrometry (ICP-AES).

The CCTS-NABA resin can adsorb several metal ions, such as vanadium, gallium, arsenic, selenium, silver, bismuth, thorium, tungsten, tin, tellurium, copper, and molybdenum at appropriate pHs. Among these metal ions, only molybdenum could be adsorbed almost completely on the resin at acidic regions. An excellent selectivity toward molybdenum could be obtained at pH 3–4. The adsorption capacity of CCTS-NABA resin for Mo(VI) was 380 mg g⁻¹ resin. Through the column pretreatment, alkali and alkaline earth metals in river water and seawater samples were successfully removed.

The CCTS-NABA resin was applied to the adsorption/collection of molybdenum in river water and seawater samples. The concentrations of molybdenum in river water samples were found in the range of 0.84 and 0.95 ppb (ng g⁻¹), whereas molybdenum in seawater was about 9 ppb. The validation of the proposed method was carried out by determining molybdenum in the certified reference materials of SLRS-4, CASS-4, and NASS-5 after passing through the CCTS-NABA resin; the results showed good agreement with the certified values.     

Synthesis of chitosan resin possessing 3,4-diamino benzoic acid moiety for the collection/concentration of arsenic and selenium in water samples and their measurement by inductively coupled plasma-mass spectrometry

A chitosan resin functionalized with 3,4-diamino benzoic acid (CCTS-DBA resin) was newly synthesized by using a cross-linked chitosan (CCTS) as base material. The adsorption behavior of trace amounts of elements on the CCTS-DBA resin was examined by the pretreatment with a mini-column and measurement of the elements by inductively coupled plasma-Mass spectrometry (ICP-MS). Arsenic(V) could be retained on the CCTS-DBA resin at pH 3 as an oxoanion of H₂AsO₄⁻. Selenium(VI) is strongly adsorbed at pH 2 and pH 3 as an oxoanion of SeO₄²⁻, while selenium(IV) as HSeO₃⁻ is adsorbed on the resin at pH 3. The sorption capacities are 82, 64, and 88 mg g⁻¹resin for As(V), Se(IV), and Se(VI), respectively. The effect of common anions and cations on the adsorption of As(V), Se(IV), and Se(VI) were studied; there was no interference from such anionic matrices as chloride, sulfate, phosphate, and nitrate up to 20 ppm, as well as from such artificial river water matrices as Na, K, Mg, and Ca after passing samples through the mini-column containing the resin. The CCTS-DBA resin was applied to the collection of arsenic and selenium species in bottled drinking water, tap water, and river water.     

Synthesis of novel chitosan resin derivatized with serine diacetic acid moiety and its application to on-line collection/concentration of trace elements and their determination using inductively coupled plasma-atomic emission spectrometry

A novel chelating resin functionalized with serine diacetic acid moiety was synthesized by using chitosan as base material, and applied to the collection/concentration of trace elements in environmental water samples, followed by the determination using inductively coupled plasma-atomic emission spectrometer (ICP-AES). The synthesized resin, crosslinked chitosan serine diacetic acid (CCTS-SDA), showed good adsorption behavior toward trace amounts of Cd, Pb, Cu, Ni, V, Ga, Sc, In, and Th in a wide pH range. Additionally, rare earth elements also can be retained on the resin at neutral pH region. The adsorbed elements can be easily eluted with 1 mol L⁻¹ of nitric acid, and their recoveries were found to be 90-100%. The CCTS-SDA was packed in a mini-column, which was then installed in a computer-controlled auto-pretreatment system (Auto-Pret System) for on-line trace elements collection and determination with ICP-AES. Experimental parameters which related to the improvement of sensitivity and reproducibility were optimized. The limits of detection (LOD) for 13 elements were found to be in sub-ppb level. The proposed method with CCTS-SDA resin was successfully applied to the determination of trace elements in river water samples. The method was validated by determining a certified reference material of river water, SLRS-4.     

Synthesis of chitosan-based resins modified with tris(2-aminoethyl)amine moiety and its application to collection/concentration and determination of trace mercury by inductively coupled plasma atomic emission spectrometry

A novel chitosan-based chelating resin modified with tris(2-aminoethyl)amine moiety (CCTS-TAA) was synthesized, and its characteristics in the collection/concentration of mercury was examined. The synthesized resin showed good adsorption toward mercury in a wide pH range, and the adsorbed mercury can be easily eluted by using 2M HNO(3) without any addition of complexing agent. The resin was then packed in a mini-column and the mini-column was installed on a computer-controlled automated-pretreatment (Auto-Pret) system coupled with inductively coupled plasma-atomic emission spectroscopy (ICP-AES) for on-line mercury collection and determination at trace level.     

Application of chitosan functionalized with 3,4-dihydroxy benzoic acid moiety for on-line preconcentration and determination of trace elements in water samples

Chitosan resin functionalized with 3,4-dihydroxy benzoic acid (CCTS-DHBA resin) was used as a packing material for flow injection (FI) on-line mini-column preconcentration in combination with inductively coupled plasma-atomic emission spectrometry (ICP-AES) for the determination of trace elements such as silver, bismuth, copper, gallium, indium, molybdenum, nickel, uranium, and vanadium in environmental waters. A 5-mL aliquot of sample (pH 5.5) was introduced to the minicolumn for the adsorption/preconcentration of the metal ions, and the collected analytes on the mini-column were eluted with 2 M HNO₃, and the eluates was subsequently transported via direct injection to the nebulizer of ICP-AES for quantification. The parameters affecting on the sensitivity, such as sample pH, sample flow rate, eluent concentration, and eluent flow rate, were carefully examined. Alkali and alkaline earth metal ions commonly existing in river water and seawater did not affect the analysis of metals. Under the optimum conditions, the method allowed the determination of metal ions with detection limits of 0.08 ng mL⁻¹ (Ag), 0.9 ng mL⁻¹ (Bi), 0.07 ng mL⁻¹ (Cu), 0.9 ng mL⁻¹ (Ga), 0.9 ng mL⁻¹ (In), 0.08 ng mL⁻¹ (Mo), 0.09 ng mL⁻¹ (Ni), 0.9 ng mL⁻¹ (U), and 0.08 ng mL⁻¹ (V). By using 5 mL of sample solution, the enrichment factor and collection efficiency were 8–12 fold and 96–102%, respectively, whereas the sample throughput was 7 samples/hour. The method was validated by determining metal ions in certified reference material of river water (SLRS-4) and nearshore seawater (CASS-4), and its applicability was further demonstrated to river water and seawater samples.     

Functionalization of chitosan with 3,4-dihydroxybenzoic acid for the adsorption/collection of uranium in water samples and its determination by inductively coupled plasma-mass spectrometry

A chitosan resin derivatized with 3,4-dihydroxybenzoic acid moiety (CCTS-DHBA resin) was newly synthesized for the collection/concentration of trace uranium by using cross-linked chitosan (CCTS) as base material, and the adsorption behavior of uranium as well as 60 elements on the resin was examined by passing the sample solutions through a mini-column packed with the resin. After the elution of the collected elements on the resin with 1 M HNO₃, the eluates were measured by inductively coupled plasma-mass spectrometry (ICP-MS).The CCTS-DHBA resin can adsorb several metal cations and several oxoanionic elements at appropriate pH. Among these metal ions, uranium shows an excellent adsorption behavior on this resin. Uranium as UO₂²⁺ species can be adsorbed on the resin by chelating mechanism with adsorption capacity of 330 mg g⁻¹ resin. Through the column treatment, the complete removal of large amounts of alkali and alkaline earth matrices without any loss of adsorption efficiency over prolonged usage were achieved with this resin.The CCTS-DHBA resin was applied to the adsorption/collection of uranium in tap water, river water and seawater samples with satisfactory results. The validation of the proposed method was carried out by analyzing uranium in the standard reference materials of SLRS-4, CASS-4, and NASS-5 after passing through the CCTS-DHBA resin, and the results showed good agreement with the certified values.     

Pretreatment of plant samples for the determination of Re by ICP-MS

In order to determine trace levels of rhenium in plant samples by ICP-MS, a pretreatment method was developed. Ten radish samples (Raphanus sativus L.) grown in solution culture containing ¹⁸⁴ReO₄ ^- were used. The samples were separated into three parts (leaves, fleshy root and fine roots), then each sample was oven-dried at 60 °C. The Re loss ratios in the samples after incineration at 450 °C for 3 hours and acid leaching at 90 °C for 3 hours were compared. There was no difference of recoveries among the sample parts, and throughout the procedure, almost 100% Re was recovered from the samples.     

An on-line preconcentration/separation system for the determination of bismuth in environmental samples by FAAS

An on-line preconcentration procedure for the determination of bismuth by flame atomic absorption spectrometry (FAAS) has been described. Lewatit TP-207 chelating resin, including iminodiacetate group, packed in a minicolumn was used as adsorbent material. Bi(III) was sorbed on the chelating resin, from which it could be eluted with 3 mol L⁻¹ HNO₃ and then introduced directly to the nebulizer-burner system of FAAS. Best preconcentration conditions were established by testing different resin quantities, acidity of sample, types of eluent, sample and eluent solution volumes, adsorption and elution flow rates, and effect of interfering ions. The detection limit of the method was 2.75 μg L⁻¹ while the relative standard deviation was 3.0% for 0.4 μg mL⁻¹ Bi(III) concentration. The developed method has been applied successfully to the determination of bismuth in pharmaceutical cream, standard reference materials and various natural water samples with satisfactory results.     

Retention of arsenate using genetically modified coryneform bacteria and determination of arsenic in solid samples by ICP-MS

A novel method for the retention of arsenate [As(V)] combining time-controlled solid-phase extraction with living bacterial biomass is presented. As(V) retention was carried out by exposing the extractant, consisting of a living double-mutant of Corynebacterium glutamicum strain ArsC1-C2, to the sample for a retention time of 1-7 min, before the arsenic distribution equilibrium between the sample solution and the extractant was established. The amount of As(V) retained in the biomass was measured by inductively coupled plasma-mass spectrometry (ICP-MS) after the sample had been treated with nitric acid. A theoretical model of the retention process was developed to describe the experimental retention-time profiles obtained with the bacterial cells. This relationship provided a feasible quantification of the retention process before steady-state was reached, providing that the agitation conditions and the retention time had been controlled. An analytical procedure for the retention/quantification of As(V) was then developed; the detection limit was 0.1 ng As(V) mL⁻¹ and the relative standard deviation 2.4-3.0%. The maximum effective retention capacity for As(V) was about 12.5 mg As (g biomass)⁻¹. The developed procedure was applied to the determination of total arsenic in coal fly ash, using a sample that had undergone oxidative pre-treatment.     

Method validation for determination of 13 elements in honey samples by ICP-MS

A method for simultaneous ICP-MS determination of 13 elements in three types of honey from Poland is described. The method was validated, and the uncertainty budget was set up. The results obtained for the relative expanded uncertainties U _rel (k = 2) were 15.1% for Al, 18.6% for B, 18.8% for Ba, 7.9% for Ca, 24.4% for Cd, 7.24% for Cu, 7.9% for K, 4.8% for Mg, 8.3% for Mn, 12.7% for Na, 14.9% for Ni, 12.5% for Pb and 13.4% for Zn. Traceability of the measurement results was established based on the use of the corn flour CRM INCT-CF-3 and the apple leaves CRM SRM 1515 and by analyzing spiked samples. Recovery rates between 94% (Zn) and 107% (Na) were found. The detection limits of all elements studied showed the suitability of the procedure for routine analyses. Summarizing it can be concluded that the described analytical procedures to measure the mass fractions of 13 elements in honey samples with established traceability and evaluated uncertainty allow to obtain reliable and internationally comparable results.     

氧化石墨烯/壳聚糖微球吸附-电感耦合等离子体质谱法测定地质样品中痕量钽EI北大核心CSCD

建立了氧化石墨烯/壳聚糖微球吸附-电感耦合等离子体质谱法测定地质样品中痕量Ta的方法。合成了氧化石墨烯/壳聚糖微球,将其应用于地质样品中痕量Ta的分离富集,采用电感耦合等离子体质谱对富集后的试液进行测定。对氧化石墨烯含量、配体种类和浓度、pH、吸附时间、吸附剂用量等吸附条件和洗脱剂类型、体积、洗脱时间等洗脱条件进行了优化,在优化的条件下,对地质样品标准物质进行测定,Ta的方法检出限为2.0 ng/g,富集倍数为26.7倍。     

Validation of bismuth film electrode for determination of cobalt and cadmium in soil extracts using ICP-MS

A study is presented on the use of the bismuth film electrode (BiFE) operated in the anodic stripping and the cathodic adsorptive stripping voltammetry (ASV, CAdSV) modes, for the determination of two trace heavy metals (Cd and Co, respectively), in soil extract samples. Two types of BiFE were examined in this study: the in situ prepared BiFE, which was employed in ASV determination of Cd, and the ex situ prepared BiFE, which was used in CAdSV of Co with dimethylglyoxime (DMG) as complexing agent. A series of unpretreated soil extracts with varying Cd and Co concentrations were analyzed, and the results obtained compared to those determined using inductively coupled plasma-mass spectrometry (ICP-MS). The results revealed the suitability of stripping analysis at the BiFE for determination of μg l⁻¹ levels of heavy metals in soil extracts. The promising results obtained here, coupled with the non-toxic nature of bismuth (in comparison to commonly used mercury electrodes employed in stripping analysis), offer great promise in centralized and decentralized analysis of trace heavy metals in complex environmental matrices.     

On-line collection/concentration and determination of transition and rare-earth metals in water samples using Multi-Auto-Pret system coupled with inductively coupled plasma-atomic emission spectrometry

On-line preconcentration and determination of transition and rare-earth metals in water samples was performed using a Multi-Auto-Pret system coupled with inductively coupled plasma-atomic emission spectrometry (ICP-AES). The Multi-Auto-Pret AES system proposed here consists of three Auto-Pret systems with mini-columns that can be used for the preconcentration of trace metals sequentially or simultaneously, and can reduce analysis time to one-third and running cost of argon gas and labor. A newly synthesized chelating resin, ethylenediamine-N,N,N′-triacetate-type chitosan (EDTriA-type chitosan), was employed in the Multi-Auto-Pret system for the collection of trace metals prior to their measurement by ICP-AES. The proposed resin showed very good adsorption ability for transition and rare-earth metal ions without any interference from alkali and alkaline-earth metal ions in an acidic media. For the best result, pH 5 was adopted for the collection of metal ions. Only 5 mL of samples could be used for the determination of transition metals, while 20 mL of samples was necessary for the determination of rare-earth metals. Metal ions adsorbed on the resin were eluted using 1.5 M nitric acid, and were measured by ICP-AES. The proposed method was evaluated by the analysis of SLRS-4 river water reference materials for trace metals. Good agreement with certified and reference values was obtained for most of the metals examined; it indicates that the proposed method using the newly synthesized resin could be favorably used for the determination of transition and rare-earth metals in water samples by ICP-AES.     

Comparison of AFS and ICP-MS detection coupled with gas chromatography for the determination of methylmercury in marine samples

Inductively coupled plasma mass spectrometry (ICP-MS) and atomic fluorescence spectrometry (AFS) coupled with gas chromatography (GC) have been evaluated as element specific detectors for the determination of methylmercury in marine samples. Detection limits for methylmercury chloride, obtained using ICP-MS and AFS, were 0.9 and 0.25 pg as Hg, respectively. Methylmercury was determined in marine tissue reference materials IAEA 142 and NIST 8044 mussel homogenate, and DOLT-2 dogfish liver by GC–AFS, with found values of 45±7, 26±4, and 671±41 ng g⁻¹, compared with certified values of 47±4, 28±2, and 693±53 ng g⁻¹. The analyses of IAEA 142 and NIST 8044 were repeated using GC–ICP-MS, with found values of 48±9 and 30±3 ng g⁻¹, respectively. Methylmercury was determined in real samples of ringed seal and beluga whale, with found values of 801±62 and 2830±113 ng g⁻¹, respectively.     

磁性氧化石墨烯的制备及其在环境水样中7种内分泌干扰物检测中的应用

制备了十二胺修饰的磁性氧化石墨烯纳米材料并将其用于磁固相萃取。在对磁固相萃取材料合成与萃取条件以及液相色谱分离等条件进行优化的基础上,建立了磁固相萃取与高效液相色谱-紫外检测对环境水样中7种内分泌干扰物的分析方法。该方法对雌酮、雌二醇、雌三醇、双酚A、17α-乙炔基雌二醇、己烷雌酚和雄烯二酮7种内分泌干扰物的检出限在0.10～0.23 nmol/L之间。将该方法分别应用于废水样品和湖水样品的加标回收试验,回收率在73.9%～112.9%和74.9%～114.7%之间。该方法操作简便,分析成本较低,可为环境水体中内分泌干扰物的分析提供技术支持。