Eluent pH Research Articles

Preparation of a novel porous organic polymer for selective extraction/determination of palladium ions from water samples

In this research, a new porphyrin-based porous organic polymer (POP), named here PPOP-UOZ-1 (UOZ stands for the University of Zabol), was synthesized through a solvothermal condensation reaction between 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (TAPP, Porph-NH2) and 2,2'-[ethane-1,2-diylbis(oxy)]dibenzaldehyde (Dialdehyde, DA). The chemical structure, morphology, and surface properties of the PPOP-UOZ-1 were assessed using numerous techniques, including TGA, BET, FT- IR, PXRD, and SEM/EDX. The nominal PPOP-UOZ-1 was then used as an adsorbent for selective (better than 92 %) extraction of Pd(II) from aqueous solutions. The adsorption process was optimized by studying the effect of various factors such as pH, the type and volume of eluent, adsorption and desorption time, and the amount of adsorbent. The results exhibited that the maximum adsorption capacity of PPOP-UOZ-1 for Pd(II) was 208.3 mg/g at a pH of 3.0, based on the Langmuir isotherm model (a determination coefficient of 0.9887). The adsorbent showed excellent selectivity for Pd(II) over other coexisting metal ions, with a recovery rate higher than 92 %. Furthermore, the PPOP-UOZ-1 could be reused for at least six adsorption-desorption cycles without substantial loss of efficiency. This proposed adsorbent and approach was further applicable for the efficient extraction of Pd(II) from environmental water samples.

Migration study of uranium in Beishan granite by the continuous column method

Abstract Radionuclide migration is an essential process in the performance and safety assessments of radioactive waste repository. This study investigates uranium migration in Beishan granite using the continuous column method, focusing on the effects of flow rate, eluent pH, and carbonate. Experimental parameters were used to perform COMSOL simulations of the migration process. The findings reveal that mechanical dispersion plays a predominant role in uranium migration in the granite column. Notably, the impact of adsorption on migration appears to be limited, likely due to the brief contact time in the experimental setup. The study successfully demonstrates the capability of COMSOL in simulating radionuclide migration, offering significant insights for the performance and safety assessments of repository.

Role of Calcium Chloride on the Eluting Process of Residual Ammonium from Weathered Crust Elution-Deposited Rare Earth Ore Tailings

A large amount of ammonium salt leaching agent will remain in the leaching site of weathered crust elution-deposited rare earth ore (WREOs). The release of residual ammonium (RA) will seriously affect the water system ecology of the mining area, and it is urgent to control it. In this paper, column eluting was used to simulate the eluting process of RA in rare earth (RE) ore tailings, and the effects of calcium chloride concentration, eluting temperature, liquid-solid ratio, eluent pH and eluent flow rate on the eluting process of RA in rare earth ore tailings were discussed. It was found that calcium chloride could effectively elute the RA from ore tailings. Eluting agent pH almost had no effect on the eluting process of RA in the pH range of 4–6, and a greater impact on it at pH 8. The flow rate could effectively enhance the elution efficiency. The optimum conditions were calcium ion concentration of 0.1 mol/L, liquid-solid ratio of 2:1, pH 4–6, flow rate of 0.6 mL/min and elution at room temperature. At this time, the elution efficiency of RA was 91.85%. The eluting process of RA in ore tailings was controlled by the inner particle diffusing according to the kinetic analysis. The reaction order was 0.368, and the activation energy of the reaction is 12.450 kJ/mol. This will provide a theoretical basis and technical support for the efficient eluting process of residual ammonium in the leaching site of WREOs.

Novel advanced materials and magnetic solid phase extraction as approaches in sample preparation to enhance the analysis of ochratoxin A in peanuts.

Ochratoxin A (OTA) is a mycotoxin that can contaminate a variety of agricultural commodities, including fruit juices and wines. The capability of a magnetic solid-phase extraction (MSPE) method with a magnetic metal-organic framework (MOF) material having a three-layer core-shell structure to improve the detection of OTA in food matrices using high performance liquid chromatography is described. Analysis of the material through X-ray diffraction (XRD) indicated the successful synthesis of the magnetic nanomaterial Fe3O4@SiO2@UiO66-NH2. Scanning electron microscopy (SEM) and Zetasizer lab indicated its nano-sized morphological features. The conditions affecting the magnetic solid-phase extraction procedure, such as material dosage, pH, composition and amount of eluent, desorption solution and desorption time were investigated to obtain the optimal extraction conditions. Under optimized conditions, the recoveries of spiked analytes at three different concentrations ranged from 95.83 to 101.5%, and the relative standard deviations were below 5%. Coupling with HPLC allowed the limit of detection to be 0.3 μg kg-1. This method is simple and specific, and can effectively avoid the influence of coexisting elements and improve the sensitivity of determination through fast MSPE of OTA. It has broad development prospects in OTA detection pre-treatment.

Simplification of the pretreatment method for phosphate oxygen isotope measurement in phosphogypsum leachate

The stacking of phosphogypsum has caused considerable phosphorus pollution in water bodies near phosphogypsum yards through surface runoff and underground infiltration. The phosphate oxygen isotope (δ18Op) tracing method has served as a valuable tool for tracing phosphorus pollution in water. However, the existing δ18Op enrichment and purification methods are complex, costly, and inefficient for phosphate recovery, particularly for phosphogypsum leachate with complex compositions. Herein, a simplified and optimized pretreatment method for δ18Op measurement in phosphogypsum leachate was developed. Zirconium/polyvinyl alcohol (Zr/PVA) gel beads showed good selectivity for phosphate enrichment from water at different initial phosphate concentrations with appropriate Zr/PVA dosage. The optimal enrichment pH value was <7, and the concentrated phosphate on the Zr/PVA gel beads could be effectively eluted in an alkaline environment. Compared with the traditional Fe or Mg coprecipitation enrichment methods, impurities in the solution showed no obvious adverse effects on the phosphate enrichment process. Further, the phosphate solution eluted from the Zr/PVA gel beads was purified by a simple adjustment of the pH instead of cation exchange in the traditional purification process. Magnesium ions in the solution could be completely removed when the pH ranged from 3.17 to 6.15, and the phosphate recovery rate could reach 98.66% when the eluent pH was 5.02. Fourier-transform infrared spectroscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy revealed that similar to traditional pretreatment method, the proposed method can obtain high-purity Ag3PO4 solids for δ18OP measurement and no isotope fractionation of δ18OP was observed. Therefore, this study provides a promising and reliable pretreatment method for δ18OP measurement, especially in complex phosphogypsum leachate.

Polytetrafluoroethylene supported polyphenol-functionalized metal–organic framework as a bio-based membrane for efficient mercury extraction from aqueous samples

In this study, we have designed and synthesized a porous membrane by functionalizing the polytetrafluoroethylene (PTEF) support with natural biomass polyphenols (tannins) grafted on amino-functionalized UiO-66 metal–organic framework to give a robust, environmentally friendly polyphenol/metal–organic framework/PTFE membrane, namely PPG-UiO-66@PTFE. Then, the nominal solid was used for the efficient extraction of mercury ions from water samples before ICP-Mass measurements. The effects of some parameters such as pH, type, and volume of eluent, eluent, sample flow rate, and co-existent ions were explored and optimized. Under optimum conditions, the limit of detection was obtained at 1.5 ng/L. The results exhibited that the presence of the co-existing ions does not affect the experimental results. The PPG-UiO-66@PTFE demonstrated superior performance compared to individual materials. This bio-based porous membrane had benefits such as a wide linear range, selectivity, renewability, and real applications in laboratory settings.

Vortex-assisted dispersive solid-phase microextraction of cadmium and copper on magnetic polystyrene-b- poly dimethyl siloxane hydrophobic block copolymer for their atomic absorption spectrometric determination in water, soft drink and food samples

The goal of the study was to create an easy-to-use, efficient method for extracting and pre-concentrating copper (Cu) and cadmium (Cd) using vortex assisted dispersive solid phase microextraction (VAdSP-μE) using a magnetic polystyrene-b-poly dimethyl siloxane block copolymer (MPCP) in different food, soft drink and water matrices using FAAS. MPCP was synthesized and characterized using FTIR NMR, Sem-EDAX, DSC, GPC. Multivariate optimization was used to statistically evaluate the various factors. Various factors such as pH, the type and volume of eluent, MPCP mass, and contact time were optimized. The VAdSP-μE method used in this study involves dispersing the MPCP in the sample solution and magnetically separating the MPCP from the sample matrix. The adsorption capacity of MPCP was obtained as 20.1 mg g−1 and 31.4 mg g−1 for Cu and Cd. Under the optimum conditions, it has been achieved 2.5–140 µg L−1 and 5.1–100 µg L−1 linear range, 0.8 and 1.7 µg L−1 LOD, 1.1% and 0.7% RSD, and 50 enhancement factors for Cu and Cd, respectively. A certified set of materials for reference was used to verify the precision of the method. Water, soft drink, and food samples all underwent the current procedure.

Selective recovery of rare earth metals from acid mine drainage by pyrrolidine diglycolamide silica column

We developed an adsorption column that can be used for rare earth recovery from acid mine drainage (AMD). 2-[2-oxo-2-(1-pyrrolidinyl)ethoxy] acetic acid was used as a functional ligand grafted onto amino silica gel, resulting in an adsorbent selective for rare earth metals. Adsorption columns for the enrichment of rare earth metals have been made using this functional silica. A flow rate of 500 µL min−1 and an eluent of pH= 2 0.013 mol L−1 DTPA were determined as the optimum operating conditions. The recovery of actual AMD using SiO2 @PYRDGA adsorption column achieved 82.29%, 75.66%, 85.10%, 78.43% for Er, Gd, Nd and La, and the purity of rare earth in AMD can be increased about 10 times after recovery. In addition, the thermodynamics, kinetics, adsorption mechanism, and theoretical calculations of the adsorption process were investigated in detail.

Facile synthesis of triazine-based porous organic polymer for the extraction and determination of nitrofuran metabolites residues from meat samples with ultra-high performance liquid chromatography-quadrupole time of flight mass spectrometry

In this work, a novel triazine-based porous organic polymers, TAPT-BPDD, was firstly synthesized by a facile method at room temperature. After characterized by FT-IR, FE-SEM, XRPD, TGA, and nitrogen-sorption experiments, TAPT-BPDD was applied as solid-phase extraction (SPE) adsorbent for the extraction of four trace nitrofuran metabolites (NFMs) from meat samples. The key parameters including the adsorbent dosage, sample pH, type and volume of eluents, type of washing solvents were evaluated in the extraction process. Combined with ultra-high performance liquid chromatography-quadrupole time of flight mass spectrometry (UHPLC-QTOF-MS/MS) analysis, good linear relationship (1–50 µg·kg−1, R2>0.9925) and low limits of detection (LODs, 0.05–0.56 µg·kg−1) were obtained under the optimal conditions. When spiked at different level, the recoveries were in the range of 72.7–111.6%. The adsorption isothermal model and extraction selectivity of TAPT-BPDD were also studied in detail. The results showed that TAPT-BPDD was a kind of promising SPE adsorbent for the enrichment of organics in food samples.

Development of a Novel LC-MS/MS Multi-Method for the Determination of Regulated and Emerging Food Contaminants Including Tenuazonic Acid, a Chromatographically Challenging Alternaria Toxin.

The regulation of food contaminants in the European Union (EU) is comprehensive, and there are several compounds in the register or being added to the recommendation list. Recently, European standard methods for analysis have also been issued. The quick analysis of different groups of analytes in one sample requires a number of methods and the simultaneous use of various instruments. The aim of the present study was to develop a method that could analyze several groups of food contaminants: in this case, 266 pesticides, 12 mycotoxins, 14 alkaloid toxins, and 3 Alternaria toxins. The main advantage of the herein described approach over other methods is the simultaneous analysis of tenuazonic acid (TEA) and other relevant food contaminants. The developed method unites the newly published standard methods such as EN 15662:2018, EN 17194:2019, EN 17256:2019, EN 17425:2021, EN 17521:2021, which describes the analysis of both regulated and emerging contaminants. The developed method is based on a QuEChERS sample preparation, followed by LC-MS/MS analysis under alkaline mobile phase conditions. The pH of the aqueous eluent was set to 8.3, which resulted in baseline separation among ergot alkaloids and their corresponding epimers, a symmetric chromatographic peak shape for analyzing TEA and fit-for-purpose sensitivity for MS/MS detection in both positive and negative ionization modes. Those compounds, which possess the corresponding isotopically labeled internal standards (ISTD), allowed for direct quantification by the developed method and no further confirmation was necessary. This was proven by satisfactory analyses of a number of quality control (QC), proficiency test (PT), and validation samples.

Determination of Neonicotinoid Insecticides in Environmental Water by the Enrichment of MIL-53 Mixed Matrix Membrane Coupled with High Performance Liquid Chromatography.

Metal organic framework based mixed matrix membranes (MOF-MMMs) were synthesized and applied for dispersive membrane extraction (DME) of four neonicotinoid insecticides (nitenpyram, thiacloprid, imidacloprid, and acetamiprid) in environmental water, combined with high performance liquid chromatography (HPLC) for determination. Several experimental conditions were optimized in detail, involving dosage percentage of MOF, extraction time, sample pH, salinity, type and volume of eluent, and elution time. High sensitivity with limits of detection and quantification were achieved as 0.013-0.064 μg L-1 and 0.038-0.190 μg L-1, respectively, and good precision with relative standard deviations were obtained as 3.07-12.78%. The proposed method has been successfully applied to determine four neonicotinoid insecticides in tap water, surface water, and seawater, satisfactory recoveries of spiked water samples were between 72.50 and 117.98%. Additionally, the MOF-MMMs showed good reusability with the extraction efficiencies almost remaining stable after 14 cycles. The MOF-MMMs based DME followed by the HPLC method can be a promising utility for the determination of neonicotinoid insecticides in environmental water samples, with high sensitivity and convenient operation.

Retention of inorganic anions using mesoporous zirconia spheres modified with anion-exchange groups as the stationary phase for ion chromatography.

A zirconia (ZrO2) stationary phase with a chemically fixed silane coupling agent (trimethyl [3-(trimethoxysilyl)propyl]ammonium chloride; TMA), which possesses quaternary ammonium functional groups, is evaluated as a separation column for ion chromatography (IC) of anions. The selectivity for anions varies depending on the amount of TMA immobilized on the ZrO2. The TMA-ZrO2, with an anion-exchange capacity of 17 ± 3µeq/g, shows an anion-exchange reaction that involves the specific retention of fluoride ion on ZrO2. The TMA-ZrO2 exhibits a decrease of the anion resolution with an increase of the eluent pH and an enhancement of the selective separation of fluorideion with an increase of the column temperature. Through this study, the TMA-ZrO2 stationary phase shows potential as a new medium for ion separation.

Electrospun UiO-66-F4/polyacrylonitrile nanofibers for efficient extraction of perfluoroalkyl and polyfluoroalkyl substances in environmental media

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are a family of emerging contaminants which are widely present in environment. In this work, novel UiO-66-F4/polyacrylonitrile (UiO-66-F4/PAN) hybrid nanofibers were firstly prepared via blend electrospinning or in-situ growth method for the pipette-tip solid phase extraction of PFASs. Characterizations demonstrate the as-synthesized UiO-66-F4/PAN nanofibers have good chemical and thermal stability, possess large surface area (248 m²/g) and mesoporous framework structure. Several extraction factors including the amount of adsorbent, pH and ionic strength of sample solution, extraction time and eluent were investigated and the optimum conditions are 20 mg of the selected sorbent, adjusting to pH 5 and adding 4% w/v NaCl to sample solution, extraction for 12 min (3 min × 4). The good adsorption affinity of UiO-66-F4/PAN for PFASs can be attributed to the extensive adsorption sites and multiple interactions including hydrophobic interaction, hydrogen bonding and F-F interaction. Low limit of detection (0.008–0.076 µg/L), limit of quantification (0.010–0.163 µg/L) and recoveries (70.84–113.57%) for 9 PFASs with relative standard deviations < 15% were achieved. When applied in the analysis of target PFASs in lake water, tap water, beverage, and shrimp muscle samples, this method could achieve robust and accurate results with sufficient sensitivity for nine PFASs.

Determination of ten iodinated X-ray contrast media by solid-phase extraction and ultra-high performance liquid chromatography coupled with high-resolution orbitrap mass spectrometry

A highly sensitive method for the simultaneous determination of ten iodinated X-ray contrast media (ICM) in environmental water samples was developed, in which samples were pretreated using solid-phase extraction and analyzed by ultra-high performance liquid chromatography coupled with high-resolution orbitrap mass spectrometry. A combination of two ENVI-Chrom P cartridges was selected due to its high recoveries of ICM. The optimized sample pH, flow rate, eluent type, and volume of eluent were 2.0, 6 mL/min, MeOH/ACN (50:50, v/v), and 6 mL, respectively. The developed method was used for the tap, surface, and waste water sample analysis, and exhibited satisfactory accuracy (80.8-118.5%), high precision (0.1-11.6%), and low detection limits (0.3-1.0 ng/L). These results indicate that this method is highly effective for the simultaneous determination of trace-level ICM in the aquatic environment.

Retention mechanisms of acidic and basic analytes on the Pentafluorophenyl stationary phase using fluorinated eluent additives

This work explores the effects of three selected fluoroalcohols - 1,1,1,3,3,3-hexafluoroisopropanol (HFIP), 1,1,1,3,3,3-hexafluorotert‑butyl alcohol (HFTB) and hexafluoro-2,3-(trifluoromethyl)-2,3-butanediol (PP) as novel eluent additives and their effect on the retention of basic and acidic analytes, using a reversed phase (RP) column with a fluorophenyl (PFP) stationary phase. In order to observe the changes in the model analytes’ retention, chromatograms were obtained at multiple (5.0; 6.0; 7.0; 8.5; 9.0 and 9.5) pH values depending on the eluent. The retention observed with fluoroalcohols was compared with that of a conventional eluent additive - ammonium acetate. When fluoroalcohols were used as eluent additives, a decrease in the retention factors (compared with ammonium acetate) was generally observed for strong acids. The retention factors of strong bases were generally higher when using HFIP and HFTB as eluent additives. The behaviour of weak bases and weak acids was more nuanced, potentially enabling interesting selectivity. The extent of the effect regarding different fluoroalcohols also varied, with HFIP and HFTB having a more significant effect on the retention of analytes than PP. The retention data were interpreted in terms of the hypothesis that four interactions are at play: (a) hydrophobic retention typical to RP; (b) π-π interactions between the analytes containing an aromatic ring and the aromatic rings on the stationary phase; (c) charge-charge or hydrogen bond interactions between the analytes and partially deprotonated fluoroalcohols adsorbed on the stationary phase and (d) a hydrogen bond or charge-charge interaction between the free silanol groups or their deprotonated forms on the stationary phase and the analytes (either neutral or ionic). Alternative selectivity obtained through fluoroalcohols on the PFP stationary phase was compared with the C18 and biphenyl stationary phases. It was demonstrated that at the same eluent pH but with a different buffer system and/or different RP stationary phases, very different selectivity and retention order can be obtained.

Magnetic solid‐phase extraction and spectrophotometric determination of pseudoephedrine in real samples

AbstractIn the present study, the magnetic iron oxide nanoparticles as an efficient sorbent were successfully utilized for the investigation of pseudoephedrine in water and urine samples before spectrophotometric evaluation. Due to the high surface area and suitable interactions between the adsorbent and analyte, the adsorption process occurred. The optimization process was applied to the parameters that might have an impact on the extraction efficiencies, including the pH, sorbent quantity, salt effect, type and volume of eluent, and the contact time affecting the adsorption and desorption of the analyte. By exerting the optimum procedure, the proper linearities ranging from 1 to 30 and 1 to 24 μg/mL with good correlation coefficients of 0.999 and 0.998 enhanced for water and urine samples. This method is proved to be as accurate and precise as it is necessary to be executed for the analytical measurements, since the measured recoveries were 99 and 96.12%, with the detection limits of 0.88 and 1.003 μg/mL for water and urine samples, respectively. The obtained results indicate that the proposed method is simple, effective, and inexpensive for the measurements of pseudoephedrine in water and urine samples.

Preparation of melon peel biochar/CoFe2O4 as a new adsorbent for the separation and preconcentration of Cu(II), Cd(II), and Pb(II) ions by solid-phase extraction in water and vegetable samples.

The present research describes the successful preparation of melon peel biochar modified with CoFe2O4 (MPBC/CoFe2O4) followed by its usage as a new sorbent to separate, preconcentrate, and determine the toxic heavy metal ions by magnetic solid-phase extraction. The metal ion desorption was performed by 0.1M HCl solution with a volume of 5.0mL. Flame atomic absorption spectrometry (FAAS) was utilized for detection of the analyte levels. SEM-EDX, TEM, XRD, and FTIR techniques were carried out to illuminate the structure of MPBC/CoFe2O4. The fundamental variables affecting the adsorption and elution efficiencies of the analyte ions including solution pH, MPBC/CoFe2O4 amount, type and concentration of eluent, adsorption and desorption equilibrium time, and sample volume were optimized. The detection limits were calculated as 0.41, 1.82, and 3.16µg L-1 for Cu2+, Cd2+, and Pb2+ ions, respectively, with the relative standard deviation of lower than 4.2%. There were no substantial interference effects on the analyte ion recovery due to the presence of foreign ions at high levels. Five minutes of contact time was adequate to attain the adsorption equilibrium. The adsorption capacity of MPBC/CoFe2O4 was obtained as 106.4, 65.4, and 188.7mgg-1 for Cu2+, Cd2+, and Pb2+ ions, respectively, by utilizing Langmuir isotherm model. The pseudo-second order model is favorable to identify the adsorption kinetics. The method was validated by spike/recovery test, and then, it was successfully implemented to determine the aforementioned analyte levels in sea and stream water, pepper, black cabbage, eggplant, and tomato samples.

Indirect Potentiometric pH Detection of Weak Acids with Absolute Quantitation by a Theoretical Approach.

A fast response potentiometric flow-through pH sensor was applied for organic acid determination. The analyte response with the pH sensor was obtained by eluent pH modification following ion exclusion chromatography with HClO4 as an eluent. The response characteristics depend on the adjusted baseline pH. The baseline pH adjustment was successfully done with an ammonia permeation device without solution mixing, which may cause analyte dilution, dispersion, and mixing noise. After pH adjustment, the pH response was universal to the equivalent of introduced analyte acids because the pH response was obtained by the titration of the permeant ammonia by the analytes. The average of limit of detections (S/N = 3) was 0.06 mM for seven target organic acids. Furthermore, the pH response follows the theoretical pH calculation with the concentrations of the eluent, pH modifier, and analyte. Thus, the analyte concentration in the sample can be theoretically calculated from the pH response without calibration by the analyte standard. Predicted concentrations of injected standards were within 5% of the actual standard concentration. Additionally, analysis of real samples was performed and compared with the conventional post-column reaction with a bromothymol blue (BTB) method. The results obtained with the present system (absolute quantification with theoretical calculation) and conventional BTB method agreed within 10% of errors.

Optimized method for analysis of ethanolamines, hydrolysis products of nitrogen mustards, from urine samples using LC-MS/MS

Highly polar ethanolamines (EAs), excreted in urine, are hydrolysis products of nitrogen mustards (NMs), which are prohibited by the Chemical Weapons Convention (CWC). The methods established for biological matrices are essential for verification analysis of the CWC related chemicals. This paper describes a new liquid chromatography-tandem mass spectrometry (LC-MS/MS) method developed for qualitative and quantitative analysis of EAs, N-ethyldiethanolamine (EDEA), N-methyldiethanolamine (MDEA) and triethanolamine (TEAOH) from urine samples. After optimization of sample preparation and chromatographic conditions, the method was fully validated. Silica solid-phase extraction (SPE) cartridges and a porous graphite carbon (PGC) column were selected for validation studies. The method is linear from 5 to 500, 0.5 to 250, and 0.5 to 500 ng/mL for TEAOH, EDEA, and MDEA, respectively. It is also precise and accurate. A minimum sample amount of 0.5 mL urine was used. The limit of quantification using this approach was 0.4, 5.5, and 6.3 ng/mL for MDEA, EDEA and TEAOH, respectively. The combination of the PGC column and high pH eluents in analysis retained and separated the studied EAs. Retention times were 2.11, 2.56 and 2.98 min for MDEA, EDEA and TEAOH, respectively. The method is applicable for verification analysis of the CWC.

First usage of ostracod species (Herpetocypris brevicaudata) carapace as a biosorbent with XAD-4 resin to determine Co(II), Cu(II) and Mn(II) trace metal ions

Powdered ostracod carapace of the species (Herpetocypris brevicaudata), an invertebrate aquatic crustacean, loaded on Amberlite XAD-4 resin, were tested as a biosorbent to determine concentrations of trace metal ions (Cu(II), Co(II), Mn(II)) in water samples prior to UV–VIS spectrophotometric analyses. Effects of sample pH, volume, type and volume of eluent, matrix interference, and flow rate of sample and eluent were examined to investigate optimum biosorption conditions of the trace metal ions.Optimum pH values for Cu(II), Co(II) and Mn(II) were around 10.0. Metals were desorbed with 1 M HCl (recovery, 90–100% and high precision; SD < 5%). Sorption capacity of AXAD-4 resin loaded with H. brevicaudata was 0.71, 0.23 and 0.64 mmol g−1 for Cu(II), Co(II) and Mn(II), respectively.Performances of the new sorbent were evaluated using certified reference material (TMDA-70.2 Ontario Lake Water).