Different Types Of Water Samples Research Articles

Use of a rhodamine-based chelator in a microfluidic paper-based analytical device for the in-situ copper quantification in natural waters

This work describes the development of a microfluidic paper-based analytical device (μPAD) for the determination of copper in fresh and marine waters. A functionalized rhodamine-based chelator was synthesized and used as a chromogenic reagent, forming a highly intense pink complex with the analyte. The aim was to create a paper device that offers optimal performance and provides in-situ, rapid and cost-effective analysis in line with World Health Organization guidelines. The influence on the determination of several physical and chemical parameters was evaluated aiming to achieve the best performance. Under optimised conditions, a linear correlation was established in the range of 0.05–0.50 mg L−1 of copper, with a limit of detection of 10 μg L−1. The accuracy of the proposed method was assessed by comparing the results obtained with the developed μPAD and the results obtained with Inductively Coupled Plasma measurements (RE < 10 %). Recovery studies were also performed using different types of water samples with no need for any prior sample pre-treatment: tap, well, river and seawater. The average recovery percentage of 101 % (RSD = 4.3 %) was obtained, a clear indication of no multiplicative matrix interferences.

A robust method for the determination of lead in water samples using flow injection hydride generation atomic absorption spectrometry

Flow injection hydride generation atomic absorption spectrometry (FI-HGAAS) is a sensitive technique for the quantification of trace amounts of lead. However, plumbane generation is not straightforward and usually HG methods for lead are not robust enough for routine analysis. The optimum pH range for Pb HG is very narrow, so strict control of the acidity of the reaction medium is required for reliable results and in some cases even acid concentrations used for sample preservation can interfere. Moreover, some elements, like Cu, can interfere in the HG reaction suppressing the Pb signal. In this paper we report the development and validation of a method for the determination of Pb in water samples that is robust towards acidity and Cu levels usually found in water samples.All hydride generation parameters were optimized, but special emphasis was put on robustness. The use of borate as a buffer significantly improved the robustness of the method towards acidity, compared to the typical non-buffered HG. Furthermore, the interference of Cu, Sb and Sn in the HG reaction was overcome using thiocyanate as a masking agent. Other elements do not interfere at levels typically found in water samples. The limit of quantification achieved (0.9 μg L−1) is below the current guideline value for Pb in drinking water (10 μg L−1). The linearity of the method was verified between the LOQ and up to 15 μg L−1. An analytical frequency of 25 samples per hour with 3 measurement replicates each was achieved. The method was applied to the analysis of 50 water samples. The concentrations found ranged from <LOD (0.3 μg L−1) and up to 88.8 μg L−1.The proposed method is robust, cost-effective, easily automated and does not require unconventional or expensive equipment. It can be applied for routine analysis of different types of water samples.

Development of field portable potentiostat using electrochemical aptasensing technology for detection of Cr(VI) in aquatic environment

Hexavalent chromium or Cr(VI) is highly toxic for humans as it causes high oxidative reactions inside cells, leading to diseases like chronic ulcers and damage to the kidneys, mucous membranes, throat, skin, and respiratory tract. Due to rapid urbanization, Cr(VI) comes into our food chain through unmonitored and uncontrolled application in agriculture fields, refineries, mills, the tanning industry, automobiles, road works, etc. Presently, the standard Cr(VI) detection is done using conventional processes, which, though accurate, has severe drawbacks in on-the-spot rapid detection in the field. Here, we have represented a handheld potentiostat towards trace-level Cr(VI) detection in aquatic environments. A Cr(VI) specific DNA aptamer immobilized screen printed electrode (SPE) has been used as the main biosensor. The device operates on an electronic peak current dumping event through mass deposition in the presence of an aptamer coupled with Cr(VI) onto the working electrode. The working range of the developed prototype is in the range of 0–1000 ppb Cr(VI), where the maximum linearity has been observed in the range of 0–500 ppb with a limit of Detection (LOD) as low as 10 ppb. The device has exhibited an excellent correlation with commercially available electrochemical workstations with a coefficient of 0.972. Moreover, the applicability of the developed device has been validated for 7 different types of water samples. To our knowledge, this is the first-ever reported simplistic resource-limited on-spot aptasensing device for Cr(VI) detection in an aquatic environment.

Determination of the radiation dose from radon ingestion and inhalation in different types of drinking water samples collected from Bethlehem province –Palestine

The objective of this study is to investigate the levels of radon gas and increase public awareness of its hazards to health in Bethlehem governorate- Palestine. The concentrations of radon-222 and radium- 226 in 79 different types of water samples were measured. The average values of radon and radium concentrations in tap water, rainwater, groundwater, and mineral water samples were 0.93 Bq/ℓ and 45.5 Bq/kg, 1.01 Bq/ℓ and 49.3 Bq/kg, 1.21 Bq/ℓ and 59.3 Bq/kg, and 0.60 Bq/ℓ and 29.2 Bq/kg, respectively. All the measured radon concentrations in the collected samples were within the limit of 11 Bq/ℓ established by UNSCEAR in 1982. The annual effective doses for ingestion and inhalation due to radon in water were calculated for adults, children, and infants using parameters introduced by UNSCEAR in 2000. The results show that there is no significant risk to public health from radon inhalation or ingestion through drinking water in the study region.

Highly versatile and automated total ammonia nitrogen compact analyzer suitable for different types of water samples

We present a versatile, robust, compact and automatic potentiometric analytical tool for in-field total ammonia nitrogen (TAN) monitoring in aqueous samples from different sources, with no sample pretreatment required.

A hydrophilic-lipophilic triazine based hyper-crosslinked polymer for efficient enrichment of nitrobenzene compounds

Sensitive, accurate, and simultaneous determination of nitrobenzene compounds (NBs) in environmental water samples is of great significance due to their high risk to human health. In this work, a new triazine-based hyper-crosslinked polymer named CC-Py was constructed via the Friedel-Crafts reaction between cyanuric chloride (CC), pyridine (Py) and 1,2-dichloroethane. Due to its excellent stability, high surface area and hydrophilic-lipophilic (amphiphilic) structure, the CC-Py exhibited a high affinity toward the NBs (nitrobenzene, 2-nitrotoluene, 2,6-dimethylnitrobenzene, 3-nitrotoluene, 4-nitrotoluene, 3-nitrochlorobenzene, 4-nitrochlorobenzene, 2-nitrochlorobenzene, 2,4-dimethylnitrobenzene, 3-nitrobromobenzene, 4-nitrobromobenzene and 4-nitroiodobenzene). Then, a CC-Py based solid-phase microextraction coupled with gas chromatography-flame ionization detection was developed to detect the twelve NBs in real water samples. The results showed that the method had low limits of detection (0.20–0.50 μg L−1), good reproducibility (relative standard deviations (RSDs) < 8.6%) and high enrichment factors (967–1590). The recoveries for the NBs in six different types of water samples were between 90% and 111% with the RSDs less than 7.5%. This work provides a facile and sensitive method for the determination of trace level of NBs in real water samples.

Comparison of the reverse osmosis membrane fouling behaviors of different types of water samples by modeling the flux change over time

Fouling of RO membranes has long been a complex but inevitable problem in wastewater reclamation. In this study, a modified intermediate blocking model with two parameters was applied to describe the flux change of RO membranes treating various water samples, including municipal secondary effluent, treated industrial wastewater, surface water, and groundwater. The model was validated by 55 sets of data reported by 13 articles, and the results were promising, with 90% of the determination coefficient (R2) exceeding 0.90. Relatively large flux and high operational pressure were found likely to aggravate membrane fouling. Treated industrial wastewater had the highest fouling potential (fouling constant k: 0.061–2.433) compared to municipal wastewater secondary effluent, surface water, and groundwater, even with similar dissolved organic carbon concentration. With industrial wastewater excluded, water samples exhibited lower fouling potential than organic matter solutions, with the majority (25%∼75%) of k distributing in 0.03–0.12, much lower compared to the major k range of the latter (0.05–0.28). This suggested a deviation in fouling behaviors between model organic matters and real water samples. Xanthan gum and guar gum were proposed to be model polysaccharides based on their model parameters, which were relatively close to real water samples.

Evaluation of DNA extraction methods for quantifying Helicobacter pylori in water with PCR inhibitors

Abstract DNA extraction methods were evaluated to reduce PCR inhibitors and quantify Helicobacter pylori directly from water samples using real-time PCR. Three nucleic acid extraction methods were evaluated for different types of water samples. While the QIAamp DNA mini kit for tissue was suitable for DNA extraction from treated water, the QIAamp DNA stool mini kit was still efficient in analyzing samples from river water after heavy rain and with high concentration of PCR inhibitors. The FastDNA SPIN Kit for Soil could extract DNA effectively from microbes in river and stream waters without heavy rain. Immunomagnetic separation (IMS) was used prior to DNA extraction and was a useful tool for reducing PCR inhibitors in influent and stream samples. H. pylori in various waters could be quantified directly by real-time PCR while minimizing the effect of PCR inhibitors by an appropriate method through the evaluation of DNA extraction methods considering the characteristics of the matrix water. The findings of the present study suggest that the types or characteristics of water sample by source and precipitation are an important factor in detecting H. pylori and they can be applied when detecting and monitoring of other pathogens in water.

Development of an Eco-Friendly Reversed-Phase HPLC Method for the Simultaneous Determination of Three Emerging Contaminants in Water Samples

Nowadays, applying green analytical principles in analytical chemistry without affecting the figures of merit is challenging to perform. One of the most important factors that contribute to greening an analytical method is to avoid the use of hazardous solvents and the tendency to use what is so-called green solvents since most of the chromatographic methods depend on using hazardous solvents. In this work, a green reversed-phase HPLC/DAD method has been developed for the simultaneous detection of three emerging contaminants in environmental water samples that have a highly negative impact on the environment. The simultaneous determination of the three emerging contaminants including diclofenac, carbamazepine, and triclosan, carried out in two different types of water samples, was achieved on Atlantis T3 RP C18 column (250 mm ×4.6 mm i.d×5 µm) using a green isocratic mobile phase; ethanol: water (85:15, v/v) pumped at a flow rate 0.8 mLmin-1. The linear concentration ranges obtained were 20-1000 ng.mL-1, 60-1000 ng.mL-1 and 60-2000 ng.mL-1 for diclofenac, carbamazepine, and triclosan respectively. The limit of detection and limit of quantitation were (3.66, 11.09), (7.51, 22.75) and (7.22, 21.88) ng.mL-1 for diclofenac, carbamazepine, and triclosan, respectively. The method was validated by the International Conference on Harmonization guidelines. Finally, two evaluation tools known as Analytical Eco-scale and Green analytical procedure index were adopted to evaluate the greenness of the proposed method. A comparison between the obtained results and the published results was carried out and no significant differences were found.

Optimization and validation of automated solid-phase microextraction arrow technique for determination of phosphorus flame retardants in water.

In the present work, a very sensitive and fully automated direct immersion PAL SPME Arrow procedure, coupled with GC-MS, has been developed and validated for determination of nine phosphorus flame retardants in different types of water samples (river, drinking and rainwater). PDMS/DVB was selected among three commercially available SPME Arrows (PDMS/DVB, DVB/PDMS/CWR and PDMS/CWR), since it resulted in the best sensitivity. The important experimental parameters were optimized via a central composite design response surface methodology and as result, extraction time of 65min, extraction temperature of 80 °C and added salt concentration of 19% (w/v), were selected as the optimum values. The optimized method showed linear response over the calibration range (2 - 500ng L-1), with R2-values higher than 0.9937. The precision (RSD%) measured by replicate analyses (n=7) was estimated at 2 and 100ng L-1 and was less than 29% and 21%, respectively. The LOQ of PAL SPME Arrow, calculated as S/N=10, was between 0.2 and 1.2ng L-1 (for triphenyl phosphate and tris-(1‑chloro‑2-propyl) phosphate, respectively) with extraction efficiencies between 5.9 and 31% (for tris-(1,3-dichloro-2-propyl) phosphate and tri-n‑butyl phosphate, respectively). To assess the performance of the developed technique for real samples, two river water samples, tap water from two regions and a rainwater sample were analyzed. Most of the target analytes were observed in the river samples with concentrations of 1.0 - 250ng L-1 and the obtained recoveries at 50ng L-1 ranged between 60 and 107%. Considering the figures of merit of the optimized method, PAL SPME Arrow-GC-MS showed to be the most sensitive analytical approach for determination of phosphorus flame retardants in water, with satisfying precision and accuracy, compared with conventional SPME-NPD, LLE-GC-MS and SPE-LC-MS/MS.

Micelle-based restricted access ion-pair microextraction of phosphate at trace levels in water samples for separation, preconcentration and determination

Abstract A new and simple micelles-rich restricted access supramolecular solvent-based liquid phase microextraction method (RASUPRASs-LPME) based on the ion-pair complex formation of phosphate (PO4 3-) ions with ammonium heptamolybdate and malachite green in acidic medium was developed. The phosphate ion concentration after microextraction of the ion-pair complex to the hexagonal aggregates of decanoic acid (DA) was measured with micro-volume UV-Vis spectrophotometer at 625 nm. All analytical parameters which are effective on the method such as acid type and concentration, supramolecular solvent volume, amount of the components forming the complex, sample volume, were optimized. The preconcentration factor (PF), limit of detection (LOD) and limit of quantification (LOQ) for the developed method was found to be 15, 9.6 and 32.1, respectively. The RA-SUPRAs-LPME method was finally applied for the analysis of the phosphate content of different types of water samples.

Simultaneous analysis of current-use pesticides and their transformation products in water using mixture-sorbent solid phase extraction and high-performance liquid chromatography-tandem mass spectrometry.

Pesticides have posed significant threats to aquatic ecosystems, yet little is known about their transformation products. The challenge is to simultaneously analyze various pesticides and transformation products in water as they have distinct physicochemical properties. A mix-mode solid phase extraction method was established to simultaneously analyze current-use pesticides and their transformation products using a mixture of hydrophile-lipophile balance, weak anion, and cation exchange resins (2:1:1, w/w/w) in combination with high-performance liquid chromatography and tandem mass spectrometry for chemical quantification. Neutral, acidic, and alkaline methanol were used as the elution solvent. Box-Behnken design was applied to optimize extraction conditions. Optimal conditions were as follows: sorbent mass, 200mg; volume of elution solvent, 5mL × 3; pH 4. The method was validated for compounds at concentrations from 20 to 1000ng/L in different types of water samples, with recovery being from 43.5 ± 3.1 to 141 ± 35%. Low method detection limits (0.02-5.6ng/L) implied that the developed method was sensitive. Finally, the method was applied to monitor current-use pesticides and their transformation products in natural waters. Frequent detection of transformation products of pesticides indicated that their contribution to aquatic risk should not be ignored.

A novel and potential chemical sensor for effective monitoring of Fe(II) ion in corrosion systems of water samples

Herein, we reported the creation of a new chemical sensor designed with high potential to evaluate the corrosion level of Fe(II) ion in different types of water samples. The designed sensor material based on the using mesoporous silica nanospheres as a scaffold after the inlaying of its surface with 1, 10 phenanthroline (PHEN). The designed chemical sensor has the capability of detecting Fe(II) ions colorimetry even at a low level of ferrous ions (∼0.03 ppb) in fast, simple steps and rapid method (5 s.). Moreover, the fabricated sensor can also reuse multiple times in the detection system with high efficiency after the recycle and regeneration of the sensor with acidic ammonium thiocyanate for the un-chelating of the ferrous ions from the used sensor and form metal free sensor again. The sensor was tested for monitoring of corrosion level in boiler real samples, and the result revealed a great match with the acquired ICP results. The results demonstrated that the fabricated PHEN sensor provides an efficient and reliable colorimetric system for monitoring and evaluating the corrosion level in boiler systems to be used as a pre-rust detector.

Solid-phase extraction based on MIL-101 adsorbent followed by gas chromatography tandem mass spectrometry for the analysis of multiclass organic UV filters in water

A metal organic framework material MIL-101 was developed as an effective solid-phase extraction adsorbent for the extraction of eleven UV filters compounds. The MIL-101 adsorbent was packed into a polypropylene cartridge and connected at the outlet tip with the Visiprep™ vacuum manifolds allowing process up to 12-port SPE samples, simultaneously. The extracted UV filters were quantified by gas chromatography-tandem mass spectrometry. Several parameters affecting the extraction efficiency of the target analytes, i.e. desorption conditions, sample pH, the addition of salt and sample volume were optimized by ANOVA analysis followed by a multifactorial design. The sample breakthrough volume of the developed method was also evaluated. The SPE-GC–MS/MS method was validated in terms of linearity (R2 ≥ 0.9973), accuracy (with satisfactory recovery from 82% to 105%), precision (relative standard deviation of less than 10%) and limits of detection ranging from 1.0 to 11.7 ng L−1. The validated method was successfully applied for the extraction and quantification of the target UV filters in different types of water samples, including lake, river, seawater and swimming pool waters. The most often found UV filters were octocrylene, 4-methylbencylidene camphor and homosalate that also came out with the highest concentrations, up to 4000 ng L−1, particularly in swimming pool waters.

An environmental friendly enrichment method for microextraction of cadmium and lead in groundwater samples: Impact on biological sample of children

A novel ionic liquid-based vortex assisted dispersive liquid–liquid micro extraction procedure(IL-VADLLμE) was proposed for the enrichment of toxic metals, cadmium (Cd) and lead (Pb) in different types of water samples, domestic treated and groundwater (tube well and hand pump). Whereas, the concentration of both toxic metals was also determined in the scalp hair of children (age ranged 1–3 years), drinking contaminated groundwater termed as exposed group, whereas for comparative purposes scalp hair of age matched children consumed domestically treated water, named as non-exposed group. To preconcentrate the trace levels of Cd and Pb, a green chelating agent, l-cysteine (2-amino-3-sulfhydrylpropanoic acid) was used for complexation, an ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate [BMIM] [PF6] utilized as extractant and hexafluorophosphate ion (PF6−) as anion pairing agent, which facilitate the enrichment of hydrophobic complexes of analytes into the acceptor phase. Various operative features for the IL-VADLLμE method like pH of standards/samples, volume of ionic liquid and sample solution, concentration of ligand, ion pair reagent and ionic liquid, vortex and electrical shaking time (for comparative purpose), were thoroughly optimized. The projected method was effectively applicable to assess the Cd and Pb in trace level in real water sample (surface and groundwater) and scalp hair samples of children belongs to exposed and non-exposed areas. The high contents of both toxic metals in scalp hair samples of children consuming groundwater indicate that the adverse impacts of both toxic metals especially Pb on the general health as well as neuron and skeletal problem, from child hood.

Toxicological and ecotoxicological evaluation of the water quality in a large and eutrophic freshwater lake of China

Effect-based methods (EBMs) are recommended as holistic approach for diagnosis and monitoring of water quality; however, the application of EBMs is still scare in China. In the present study, water quality of the freshwater lake Taihu (China) was investigated by EBMs. Different types of water samples were collected from three bays of the lake during 2015, 2016 and 2017. A battery of seven effect-based bioassays, including both specific and non-specific toxicity assays, was used. The bioassay battery was recently suggested based on joint activities of the EU project SOLUTIONS and the NORMAN network on emerging pollutants and is also under discussion for being implemented into monitoring activities in the context of the European Water Framework Directive (WFD). Adverse effects were observed towards the primary producer, primary consumer and fish, indicating the potential ecotoxicity of water in Taihu Lake. Mutagenic and estrogenic effects were found in the Ames fluctuation assay and ERα CALUX (Chemically Activated Luciferase Gene-eXpression) assay, respectively, highlighting the potential risks on human health. Algal growth inhibition and mutagenic effects can be observed during each of the three years. Acute toxicity towards Daphnia magna and estrogen receptor agonistic effects were found in at least one of the samples collected in 2016 and 2017, but not in 2015. The endpoints for fish toxicity in the Danio rerio fish embryo test included both lethal and additionally several sublethal effects (only for samples from 2017) and were not compared between years. Algal growth inhibition, fish embryo toxicity, mutagenic effect and estrogenicity were observed in each of the three bays, while Daphnia acute toxicity was only found in Zhushan Bay. Taking together, this study provides a big picture on the water quality of Taihu Lake. The battery of effect-based tools is promising to be a routine for water quality monitoring in China.

Direct immersion thin-film microextraction method based on the sorption of pyrrolidine dithiocarbamate metal chelates onto graphene membranes followed by total reflection X-ray fluorescence analysis

This work reports on the development of a direct immersion thin-film microextraction procedure for the simultaneous preconcentration of different metal ions present in water samples using graphene membranes as novel sorptive platforms. The method relies on the sorption of metal ions as pyrrolidine dithicarbamate (APDC) chelates prior to determination by Total Reflection X-Ray Fluorescence technique (TXRF). Easy-to-manipulate and flexible graphene membranes were prepared by thermal reduction of graphene oxide and drop-casting onto a glass support. The sorption of Co(II), Ni(II), As(III), Se(IV), Au(III), Hg(II), Pb(II) and Bi(III) as their APDC chelates onto the graphene membranes was carried out under the following optimal conditions: reduction time for the synthesis of graphene membranes, 8 min; pH 3; 0.04% (w/v) APDC concentration; 50 mL sample volume; 900 rpm stirring rate; 10 min extraction time; room temperature conditions. Detection limits in the range of 0.2–0.6 μg/L were achieved, which were much below the maximum contaminant levels in waters established by the different regulations. In order to assess the trueness of the method, two certified reference materials (i.e. QC1014 and QC1187) were analyzed. The method is simple, very sensitive and solvent free, being suitable for the determination of metal ions at trace levels in different types of water samples.

Development and validation of a GC–MS/MS method for priority polycyclic aromatic hydrocarbons quantification in different types of water samples

AbstractA sensitive analytical method has been developed for the determination of polycyclic aromatic hydrocarbons in water, including priority pollutants according to the European Union, by gas chromatography coupled to triple quadrupole tandem mass spectrometry (GC‐QqQ‐MS/MS). The sample treatment was based on a solid‐phase extraction method which was validated in four different types of water: seawater, drinking water, untreated inland water and wastewater according to CD 2002/657/EC and SANTE/11813/2017 guidelines. Obtained recovery, studied at three concentration levels (1.7, 5.6 and 25.0 ng/L), was in the range 77–108%. Precision values were ≤ 17% and 22% for intra‐day and inter‐day precision, respectively. Linearity was studied in the range 1.4‐100 ng/L, and the obtained determination coefficients (R2) were ≥ 0.9962. Limits of detection were in the range from 1.0 to 3.0 ng/L, whereas limits of quantification were established from 1.4 to 5.0 ng/L. The validated method was successfully accredited according to ISO/IEC 17025 international standard (including calculation of uncertainty) and applied to routine analysis of real water samples.

Reduced graphene oxide-coated magnetic-nanoparticles as sorbent for the determination of phthalates in environmental samples by micro-dispersive solid-phase extraction followed by ultra-high-performance liquid chromatography tandem mass spectrometry

In this work, the suitability of Fe3O4 nanoparticles coated with reduced-graphene oxide as sorbent was evaluated for the extraction of a group of fourteen phthalic acid esters (i.e. benzylbutyl phthalate (BBP), bis-2-n-butoxyethyl phthalate (DBEP), dibutyl phthalate (DBP), diisobutyl phthalate (DIBP), dicyclohexyl phthalate (DCHP), bis-2-ethoxyethyl phthalate (DEEP), diisodecyl phthalate (DIDP), diisononyl phthalate (DINP), bis-isopentyl phthalate (DIPP), bis-(2-methoxyethyl) phthalate (DMEP), dimethyl phthalate (DMP), di-n-octyl phthalate (DNOP), bis-n-pentyl phthalate (DNPP), dipropyl phthalate (DPP)) from environmental samples. Extraction was carried out using magnetic-micro dispersive solid-phase extraction while separation, identification and quantification of the target analytes were achieved by ultra-high-performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry. The methodology was validated for three different types of water samples using dibutyl phthalate-3,4,5,6-d4 as internal standard for all of them. Recovery values ranged from 70 to 120% for the three matrices with relative standard deviation values lower than 20%. Limits of quantification of the method achieved were in the range 6–178 ng/L for all samples and analytes. The methodology was applied for the evaluation of real samples finding the presence of DMP, DPP, BBP, DIBP and DBP in some of the analysed matrices.

Graphene oxide covalently modified with 2,2′-iminodiacetic acid for preconcentration of Cr(III), Cu(II), Zn(II) and Pb(II) from water samples prior to their determination by energy dispersive X-ray fluorescence spectrometry

A novel adsorbent, graphene oxide modified with 2,2′-iminodiacetic acid (GO-IDA), was synthesized by nucleophilic substitution of dimethyl-2,2′-iminodiacetate hydrochloride to the surface of graphene oxide (GO). It was applied in the dispersive micro-solid phase extraction (DMSPE) for the simultaneous preconcentration of selected heavy metal ions from water samples prior to determination by Energy Dispersive X-Ray Fluorescence Spectrometry (EDXRF). The experiments show that at pH 6.5 GO-IDA can be used for quantitative adsorption of Cr(III), Cu(II) Zn(II) and Pb(II) ions from water samples. The adsorption capacities of GO-IDA towards Cr(III), Cu(II), Zn(II) and Pb(II) ions are found to be 117.1, 108.4, 119.6, and 80.7 mg g−1, respectively. The experimental data are fitted better by the Langmuir model than by the Freundlich model. Under optimal preconcentration conditions the linear response between analyte concentration and fluorescence radiation intensity was observed within 1−200 ng mL−1 for Cr(III) and Cu(II), 1−140 ng mL−1 for Zn(II), and 1−100 ng mL−1 for Pb(II) ions. The uncertainty of the developed method does not exceed 4.3%. The detection limits are 0.11, 0.06, 0.07 and 0.08 ng mL−1 for Cr(III), Zn(II) Cu(II) and Pb(II), respectively. The enrichment factors obtained for the 50 mL sample volume are in 450−1465 range. The DMSPE-EDXRF procedure was applied for the determination of Cr(III), Cu(II), Zn(II) and Pb(II) ions in different types of water samples. The accuracy of the procedure was verified by the analysis of Certified Reference Material: NIST 1640a (Trace elements in natural water).