Synthesis of cross-linked chitosan modified with the glycine moiety for the collection/concentration of bismuth in aquatic samples for ICP-MS determination.

A chelating resin, cross-linked chitosan modified with the glycine moiety (glycine-type chitosan resin), was developed for the collection and concentration of bismuth in aquatic samples for ICP-MS measurements. The adsorption behavior of bismuth and 55 elements on glycine-type chitosan resin was systematically examined by passing a sample solution containing 56 elements through a mini-column packed with the resin (wet volume; 1 ml). After eluting the elements adsorbed on the resin with nitric acid, the eluates were measured by ICP-MS. The glycine-type chitosan resin could adsorb several cations by a chelating mechanism and several oxoanions by an anion-exchange mechanism. Especially, the resin could adsorb almost 100% Bi(III) over a wide pH region from pH 2 to 6. Bismuth could be strongly adsorbed at pH 3, and eluted quantitatively with 10 ml of 3 M nitric acid. A column pretreatment method with the glycine-type chitosan resin was used prior to removal of high concentrations of matrices in a seawater sample and the preconcentration of trace bismuth in river water samples for ICP-MS measurements. The column pretreatment method was also applied to the determination of bismuth in real samples by ICP-MS. The LOD of bismuth was 0.1 pg ml(-1) by 10-fold column preconcentration for ICP-MS measurements. The analytical results for bismuth in sea and river water samples by ICP-MS were 22.9 +/- 0.5 pg ml(-1) (RSD, 2.2%) and 2.08 +/- 0.05 pg ml(-1) (RSD, 2.4%), respectively.     

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.     

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.     

Adsorption behavior of uranium(VI) and other ionic species on cross-linked chitosan resins modified with chelating moieties

Cross-linked chitosan resins with catechol (catechol-type chitosan, type 1 and type 2), iminodiacetic acid (IDA-type chitosan), iminodimetylphosphonic acid (IDP-type chitosan), phenylarsonic acid (phenylarsonic acid-type chitosan), or serine (serine-type chitosan) were prepared for the collection and concentration of uranium(VI). The adsorption behavior of U(VI) and other ionic species, such as metal ions and oxo-acid ions, on the cross-linked chitosan (base material) and chitosan resins modified with chelating moieties was examined using a column procedure. Especially, the catechol-type chitosan (type 2) adsorbed U(VI) at pH 2-7, and selectively collected U(VI) at acidic pH regions by forming a stable chelate with hydroxyl groups of catechol moiety introduced to the chitosan. Also, the adsorption properties of cationic and anionic species present in aquatic media were elucidated. The adsorption ability for U(VI) was in the order: catechol-type chitosan (type 2) > serine-type chitosan > phenylarsonic acid-type chitosan > the others. The catechol-type chitosan (type 2) was useful for the collection and concentration of uranium(VI).     

Speciation of chromium in seawater by ICP-AES with dual mini-columns containing chelating resin.

A method for the preconcentration and speciation of chromium in seawater was developed. On-line preconcentration and determination were carried out by using inductively coupled plasma atomic emission spectrometry (ICP-AES) with dual mini-columns containing a chelating resin. In this system, Cr(III) was collected on the first column. The effluent containing residual chromium from the first column was collected on the second column after passing through a reduction-switching unit, in which the reducing agent was introduced, or not, for the reduction of Cr(VI) to Cr(lII). Cr(VI) was determined as the difference between the concentration of pre-reduced Cr(VI) and Cr(III) in the effluent from the first column. The detection limits for Cr(III) and Cr(VI) were 0.04 and 0.09 microg l(-1), respectively.     

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.     

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 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.     

Sequential-injection on-line preconcentration using chitosan resin functionalized with 2-amino-5-hydroxy benzoic acid for the determination of trace elements in environmental water samples by inductively coupled plasma-atomic emission spectrometry

A new chelating resin using chitosan as a base material was synthesized. Functional moiety of 2-amino-5-hydroxy benzoic acid (AHBA) was chemically bonded to the amino group of cross-linked chitosan (CCTS) through the arm of chloromethyloxirane (CCTS-AHBA resin). Several elements, such as Ag, Be, Cd, Co, Cu, Ni, Pb, U, V, and rare earth elements (REEs), could be adsorbed on the resin. To use the resin for on-line pretreatment, the resin was packed in a mini-column and installed into a sequential-injection/automated pretreatment system (Auto-Pret System) coupled with inductively coupled plasma-atomic emission spectrometry (ICP-AES). The sequential-injection/automated pretreatment system was a laboratory-assembled, and the program was written using Visual Basic software. This system can provide easy operation procedures, less reagent consumption, as well as less waste production.

Experimental variables considered as effective factors in the improvement sensitivity, such as an eluent concentration, a sample and an eluent flow rate, pH of samples, and air-sandwiched eluent were carefully optimized. The proposed system provides excellent on-line collection efficiency, as well as high concentration factors of analytes in water samples, which results in highly sensitive detection of ultra-trace and trace analysis. Under the optimal conditions, the detection limits of 24 elements examined are in the range from ppt to sub-ppb levels. The proposed method was validated by using the standard reference material of a river water, SLRS-4, and the applicability was further demonstrated to the on-line collection/concentration of trace elements, such as Ag, Be, Cd, Co, Cu, Ni, Pb, U, V, and REEs in water samples.     

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.     

Application of iminodiacetate chelating resin muromac A-1 in on-line preconcentration and inductively coupled plasma optical emission spectroscopy determination of trace elements in natural waters

On-line system incorporating a microcolumn of Muromac A-1 resin was used for the developing of method for preconcentration of trace elements followed by inductively coupled plasma (ICP) atomic emission spectrometry determination. A chelating type ion exchange resin has been characterized regarding the sorption and subsequent elution of 24 elements, aiming to their preconcentration from water samples of different origins. The effect of column conditioning, pH and flow rate during the preconcentration step, and the nature of the acid medium employed for desorption of the retained elements were investigated. A sample (pH 5) is pumped through the column at 3 ml min⁻¹ and sequentially eluted directly to the ICP with 3 M HNO₃/HCl mixtures. In order to remove residual matrix elements from the column after sample loading a short buffer wash was found to be necessary. The effectiveness of the matrix separation process was illustrated. The procedure was validated by analyzing several simple matrices, Standard River water sample as well as artificial seawater. Proposed method can be applied for simultaneous determination of In, Tl, Ti, Y, Cd, Co, Cu and Ni in seawater and for multielement trace analysis of river water. Recovery at 1 μg l⁻¹ level for the determination of investigated 24 elements in pure water ranged from 93.1 to 96% except for Pd (82.2%) and Pb (88.1%). For the same concentration level for seawater analysis recovery was between 81.9 and 95.6% except for Hg (38.2%).     

Synthesis and efficiency of a spherical macroporous epoxy-polyamide chelating resin for preconcentrating and separating trace noble metal ions

The determination of noble metals in various materials usually requires their preconcentration and separation from other elements. In spite of the improvements in analytical instrumentation and the development of new analytical techniques such as ICP-MS, which are capable of detecting metal ions at ppt levels, the interference caused by the sample matrix still exists and is perhaps the most serious problem, making a pre-determination enrichment step necessary. Thus, the search for efficient preconcentration and separation methods is essential. A series of chelating resins that can selectively adsorb noble metal ions from aqueous solutions have been described. Functional groups, such as salicylaldoxime and thiosemicarbazide have been incorporated in cross-linked polymers or porous silica gel. These resins have very high selectivity for one or several types of noble metal ion. However, desorption of noble metals from these resins is usually difficult. Hence, the development of an adsorbent from which noble metals can be easily desorbed is needed. In this paper, a new spherical macroporous epoxy-polyamide chelating resin that met this requirement was synthesized by one step reaction. The synthesis of the resin was safe, rapid and more simple and economical than many report adsorbents. Meanwhile, the resin showed more advantages: better acid and alkali resistance; higher adsorption capacity and lower preconcentration concentrations. A resin column procedure combined with inductively coupled plasma atomic emission spectrometry (ICP-AES) for the determination of trace Rh(III), Ru(III) and Ir(IV) in real samples was established.     

Synthesis and efficiency of an epoxy-tannin chelating resin for preconcentrating and separating various rare elements

A new epoxy-tannin chelating resin was synthesized from epoxy resin and used for the preconcentration and separation of rare elements. The acidity, rate, reuse, capacity and interference on the adsorption of ions on the resin as well as the conditions of desorption of these ions from the resin were investigated by means of inductively coupled plasma atomic emission spectrometry (ICP-AES). The composition of the resin and mechanism of enrichment for some ions were discussed. The results show that the relative standard deviations for the determination of 50 ng ml⁻¹ Ga(III), In(III), Bi(III) and Sn(IV), 10 ng ml⁻¹ La(III), Y(III), Cr(III), Ti(IV) and V(V) and 1.0 ng ml⁻¹ Be(II) were in the range of 0.5–4.5%. The contents of these elements in a sample solution from a smelter determined by the new method were in agreement with those values obtained by Zeeman atomic absorption spectrometry with an average error <3.4%.     

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.     

Solid phase extraction and preconcentration of uranium(VI) and thorium(IV) on Duolite XAD761 prior to their inductively coupled plasma mass spectrometric determination

A simple and effective method is presented for the separation and preconcentration of thorium(IV) and uranium(VI) by solid phase extraction on Duolite XAD761 adsorption resin. Thorium(IV) and uranium(VI) 9-phenyl-3-fluorone chelates are formed and adsorbed onto the Duolite XAD761. Thorium(IV) and uranium(VI) are quantitatively eluted with 2 mol L⁻¹ HCl and determined by inductively coupled plasma-mass spectrometry (ICP-MS). The influences of analytical parameters including pH, amount of reagents, amount of Duolite XAD761 and sample volume, etc. were investigated on the recovery of analyte ions. The interference of a large number of anions and cations has been studied and the optimized conditions developed have been utilized for the trace determination of uranium and thorium. A preconcentration factor of 30 for uranium and thorium was achieved. The relative standard deviation (N = 10) was 2.3% for uranium and 4.5% for thorium ions for 10 replicate determinations in the solution containing 0.5 μg of uranium and thorium. The three sigma detection limits (N = 15) for thorium(IV) and uranium(VI) ions were found to be 4.5 and 6.3 ng L⁻¹, respectively. The developed solid phase extraction method was successively utilized for the determination of traces thorium(IV) and uranium(VI) in environmental samples by ICP-MS.     

On-line preconcentration using dual mini-columns for the speciation of chromium(III) and chromium(VI) and its application to water samples as studied by inductively coupled plasma-atomic emission spectrometry

On-line preconcentration system for the selective, sensitive and simultaneous determination of chromium species was investigated. Dual mini-columns containing chelating resin were utilized for the speciation and preconcentration of Cr(III) and Cr(VI) in water samples. In this system, Cr(III) was collected on first column packed with iminodiacetate resin. Cr(VI) in the effluent from the first column was reduced to Cr(III), which was collected on the second column packed with iminodiacetate resin. Hydroxyammonium chloride was examined as a potential reducing agent for Cr(VI) to Cr(III).The effects of pH, sample flow rate, column length, and interfering ions on the recoveries of Cr(III) were carefully studied. Five millilitres of a sample solution was introduced into the system. The collected species were then sequentially washed by 1 M ammonium acetate, eluted by 2 M nitric acid and measured by ICP-AES. The detection limit for Cr(III) and Cr(VI) was 0.08 and 0.15 μg l⁻¹, respectively. The total analysis time was about 9.4 min.The developed method was successfully applied to the speciation of chromium in river, tap water and wastewater samples with satisfied results.     

Preconcentration of rare earth elements on silica gel loaded with 1-phenyl-3-methyl-4-benzoylpyrazol-5-one prior to their determination by ICP-AES.

A new chelating resin, silica gel loaded with 1-phenyl-3-methyl-4-benzoylpyrazol-5-one (PMBP), was prepared and used for the preconcentration of trace amounts of rare earth elements (REEs) in water samples prior to their determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). REEs (La, Eu, Yb and Y) were quantitatively retained on the column packed with modified silica gel in the pH range 5 - 8 and separated from the matrix, and then recovered by eluting with 2.0 mol L(-1) HNO3. The adsorption capacity of modified silica gel for La, Eu, Yb and Y was 0.208, 0.249, 0.239 and 0.224 mmol g(-1), respectively. The method has been successfully applied for the determination of La, Eu, Yb and Y in geological and environmental samples with satisfactory results.     

Anion-exchange behavior of rare earths,thorium, protactinium and uranium in thiocyanate-chloride media

The anion exchange of rare earths(III), thorium(IV), protactinium(V) and uranium (VI) from thiocyanate-chloride media was investigated. The equilibrium, distribution study showed that the rare earths(III) and yttrium(III) were not significantly adsorbed on a basic anion-exchangc resin, while thorium(IV), protactinium(V) and uranium(VI) were strongly adsorbed. Adsorption from the thiocyanate-chloride solutions is in the order, U(Vl) > Pa(V) > Th(IV). The separation of rare earths(III) or yttrium(III), thorium(IV), protactinium(V) and uranium(VI) was successfully accomplished by column elution in thiocyanate-chloride media. A rapid and effective ion-exchange method for separating protactinium-233 from irradiated thorium(IV) is also presented.     

High-capacity chitosan-based chelating resin for on-line collection of transition and rare-earth metals prior to inductively coupled plasma-atomic emission spectrometry measurement

High-capacity chitosan-based chelating resin, N-(2-hydroxyethyl)glycine-type chitosan, was synthesized using chloromethyloxirane (CMO) as a cross-linker and a coupling arms and hydroxylethylamine and bromoacetic acid as a synthesizer for the N-(2-hydroxyethyl)glycine chelating moiety. The CMO could bind with both of hydroxyl and amino group of the chitosan resin, and then couple with the chelating moiety. Increasing the amounts of chelating moiety could increase the capacity of the resin toward metal ions. Most transition and rare-earth metals could adsorb quantitatively on the resin at wide pH ranges and could be separated from alkaline and alkaline-earth metals. The resin was packed in a mini-column (40 mm length × 2 mm i.d.) which was installed in a Multi-Auto-Pret system. The Multi-Auto-Pret system coupled with ICP-AES was successfully applied to the determination of transition and rare-earth metals in river water samples.     

Preconcentration of Rare Earth Elements in Seawater with Chelating Resin Having Fluorinated β‐Diketone Immobilized on Styrene Divinyl Benzene for their Determination by ICP‐OES

An analytical method has been developed for the preconcentration of rare earth elements (REEs) in seawater for their determination by inductively coupled plasma optical emission spectrometry (ICP‐OES). An indigenously synthesized chelating resin was used for the preconcentration of (REEs) which was based on immobilization of fluorinated β‐diketone group on solid support styrene divinyl benzene. Sample solutions (adjusted to optimized pH) were passed through a polyethylene column packed with 250 mg of the resin. Experimental conditions consisting of pH, sample flow rate, sample volume and eluent concentration were optimized. The established method has been applied for the preconcentration of light, medium and heavy REEs in coastal sea water samples for their subsequent determination by (ICP‐OES). Percentage recoveries of La, Ce, Nd, Sm, Eu, Gd, Dy, Er, Yb and Lu were ≥ 95%, a preconcentration factor of 200 times, and relative standard deviations < 5% were achieved.