Aptamer‐functionalized Fe3O4 magnetic nanoparticles as a solid‐phase extraction adsorbent for the selective extraction of berberine from Cortex phellodendri

The extraction adsorbent was fabricated by immobilizing the highly specific recognition and binding of aptamer onto the surface of Fe₃O₄ magnetic nanoparticles, which not only acted as recognition elements to recognize and capture the target molecule berberine from the extract of Cortex phellodendri , but also could favor the rapid separation and purification of the bound berberine by using an external magnet. The developed solid‐phase extraction method in this work was useful for the selective extraction and determination of berberine in Cortex phellodendri extracts. Various conditions such as the amount of aptamer‐functionalized Fe₃O₄ magnetic nanoparticles, extraction time, temperature, pH value, Mg²⁺ concentration, elution time and solvent were optimized for the solid‐phase extraction of berberine. Under optimal conditions, the purity of berberine extracted from Cortex phellodendri was as high as 98.7% compared with that of 4.85% in the extract, indicating that aptamer‐functionalized Fe₃O₄ magnetic nanoparticles‐based solid‐phase extraction method was very effective for berberine enrichment and separation from a complex herb extract. The applicability and reliability of the developed solid‐phase extraction method were demonstrated by separating berberine from nine different concentrations of one Cortex phellodendri extract. The relative recoveries of the spiked solutions of all the samples were between 95.4 and 111.3%, with relative standard deviations ranging between 0.57 and 1.85%.     

Estimation of the efficiencies and uncertainties of the extraction and cleanup steps of pesticide residue determination in cucumber using <Superscript>14</Superscript>C-carbaryl

The estimation of the uncertainty of measurement has, nowadays, become an integral part of analytical results. The uncertainty and efficiency of extraction and cleanup are very important components of a pesticide residue analytical method. In this work, for a quick review of extraction and cleanup efficiency and to evaluate the individual analysis steps during method adaptation, ¹⁴C-carbaryl was applied at all fortification levels. Then, further analyses, such as ethylacetate extraction, filtration, evaporation and cleanup, were performed. The calibration of gel chromatograph column, performed with both ¹⁴C-carbaryl and fortification mixture (dichlorvos, malathion and chlorpyrifos), showed that pesticide fractions came through the column between the 8- and 23-mL fractions. The overall recovery of ¹⁴C-carbaryl after the extraction and cleanup step was 0.91, with the relative uncertainty of 0.084. Using the “bottom-up” approach, the uncertainty of extraction u _cEX and cleanup u _cGPC were 0.033 and 0.107, respectively. The combined standard uncertainty u _c associated with the described analytical method was 0.112. Similar values were obtained using the alternative “top-down” approach: uncertainty of extraction u _ct1 was 0.039, uncertainty of cleanup u _ct2 was 0.108 and the combined standard uncertainty u _cAV was 0.081. Both approaches showed that the uncertainty of cleanup was the main source of combined standard uncertainty.     

Determination of arsenic species in solid matrices utilizing supercritical fluid extraction coupled with gas chromatography after derivatization with thioglycolic acid n‐butyl ester

A method using derivatization and supercritical fluid extraction coupled with gas chromatography was developed for the analysis of dimethylarsinate, monomethylarsonate and inorganic arsenic simultaneously in solid matrices. Thioglycolic acid n‐butyl ester was used as a novel derivatizing reagent. A systematic discussion was made to investigate the effects of pressure, temperature, flow rate of the supercritical CO₂, extraction time, concentration of the modifier, and microemulsion on extraction efficiency. The application for real environmental samples was also studied. Results showed that thioglycolic acid n‐butyl ester was an effective derivatizing reagent that could be applied for arsenic speciation. Using methanol as modifier of the supercritical CO₂ can raise the extraction efficiency, which can be further enhanced by adding a microemulsion that contains Triton X‐405. The optimum extraction conditions were: 25 MPa, 90°C, static extraction for 10 min, dynamic extraction for 25 min with a flow rate of 2.0 mL/min of supercritical CO₂ modified by 5% v/v methanol and microemulsion. The detection limits of dimethylarsinate, monomethylarsonate, and inorganic arsenic in solid matrices were 0.12, 0.26, and 1.1 mg/kg, respectively. The optimized method was sensitive, convenient, and reliable for the extraction and analysis of different arsenic species in solid samples.     

Graphene‐coated magnetic‐sheet solid‐phase extraction followed by high‐performance liquid chromatography with fluorescence detection for the determination of aflatoxins B1, B2, G1, and G2 in soy‐based samples

A new method named graphene‐coated magnetic‐sheet solid‐phase extraction based on a magnetic three‐dimensional graphene sorbent was developed for the extraction of aflatoxins prior to high‐performance liquid chromatography with fluorescence detection. The use of a perforated magnetic‐sheet for fixing the magnetic nanoparticles is a new feature of the method. Hence, the adsorbent particles can be separated from sample solution without using an external magnetic field. This made the procedure very simple and easy to operate so that all steps of the extraction process (sample loading, washing, and desorption) were carried out continuously using two lab‐made syringe pumps. The factors affecting the performance of extraction procedure such as the extraction solvent, adsorbent dose, sample loading flow rate, ionic strength, pH, and desorption parameters were investigated and optimized. Under the optimal conditions, the obtained enrichment factors and limits of detection were in the range of 205–236 and 0.09–0.15 μg/kg, respectively. The relative standard deviations were <3.4 and 7.5% for the intraday (n = 6) and interday (n = 4) precisions, respectively. The developed method was successfully applied to determine aflatoxins B₁, B₂, G₁, and G₂ in different soy‐based food samples.     

Rapid and sensitive determination of major polyphenolic components in Euphoria longana Lam. seeds using matrix solid‐phase dispersion extraction and UHPLC with hybrid linear ion trap triple quadrupole mass spectrometry

A rapid and sensitive method for the extraction and determination of four major polyphenolic components in Euphoria longana Lam. seeds is presented for the first time based on matrix solid‐phase dispersion extraction followed by ultra high performance liquid chromatography with hybrid triple quadrupole linear ion trap mass spectrometry. Matrix solid‐phase dispersion method was designed for the extraction of Euphoria longana seed constituents and compared with microwave‐assisted extraction and ultrasonic‐assisted extraction methods. An Ultra high performance liquid chromatography with hybrid triple quadrupole linear ion‐trap mass spectrometry method was developed for quantitative analysis in multiple‐reaction monitoring mode in negative electrospray ionization. The chromatographic separation was accomplished using an ACQUITY UPLC BEH C₁₈ (2.1 mm × 50 mm, 1.7 μm) column with gradient elution of 0.1% aqueous formic acid and 0.1% formic acid in acetonitrile. The developed method was validated with acceptable linearity (r² > 0.999), precision (RSD ≤ 2.22%) and recovery (RSD ≤ 2.35%). The results indicated that matrix solid‐phase dispersion produced comparable extraction efficiency compared with other methods nevertheless was more convenient and time‐saving with reduced requirements on sample and solvent volumes. The proposed method is rapid and sensitive in providing a promising alternative for extraction and comprehensive determination of active components for quality control of Euphoria longana products.     

Study of enrichment factors for six β‐blockers in aliphatic alcohols by hollow‐fiber liquid‐phase microextraction

The selectivity of a suitable organic solvent is key for extraction in liquid‐phase microextraction experiments. Nevertheless, the screening process remains a daunting task. Our research aimed to study the relationship between extraction efficiency and extraction solvents, analytes, and finally select the appropriate extraction solvent. In the present article, β‐blockers and six extraction solvents were chosen as the models and hollow‐fiber liquid‐phase microextraction was conducted. The relationship was built by statistical analysis on the data. Factors affecting extraction efficiency including the logarithms of the octanol/water partition coefficient (logP_o/w) of analytes, acid dissociation constants, the logarithms of the octanol/water partition coefficient of solvents and pH of the sample solution were investigated. The results showed that a low water solubility of extraction solvent is the foundation to ensure higher extraction efficiency. Moreover, when ΔlogP_o/w > 0, a higher extraction efficiency is observed at lower ΔlogP_o/w, on the contrary, when ΔlogP_o/w < 0, extraction efficiency is higher as the absolute value of ΔlogP_o/w becomes greater. Finally, the relationship between enrichment factor and extraction solvents, analytes was established and a helpful guidance was provided for the selection of an optimal solvent to obtain the best extraction efficiency by liquid‐phase microextraction.     

Magnetic mixed hemimicelles solid‐phase extraction coupled with high‐performance liquid chromatography for the extraction and rapid determination of six fluoroquinolones in environmental water samples

In this study, a mixed hemimicelle solid‐phase extraction method based on Fe₃O₄ nanoparticles coated with sodium dodecyl sulfate was applied for the preconcentration and fast isolation of six fluoroquinolones in environmental water samples before high‐performance liquid chromatography determination. The main factors affecting the extraction efficiency of the analytes, such as amount of surfactant, amount of Fe₃O₄ nanoparticles, extraction time, sample volume, sample pH, ionic strength, and desorption conditions, were investigated and optimized. The method has detection limits from 0.05 to 0.1 ng/mL and good linearity (r ≥ 09948) in the range 0.1–200 ng/mL depending on the fluoroquinolone. The enrichment factor is ～200. The recoveries (at spiked levels of 1, 5, and 50 ng/mL) are in the range of 79–120%.     

Rapid and cost‐effective method for the simultaneous quantification of seven alkaloids in Corydalis decumbens by microwave‐assisted extraction and capillary electrophoresis

A rapid and cost‐effective method based on microwave‐assisted extraction followed by capillary electrophoresis was developed for simultaneous quantification of seven alkaloids in Corydalis decumbens for the first time. The main parameters affecting microwave‐assisted extraction and capillary electrophoresis separation were investigated and optimized. The optimal microwave‐assisted extraction was performed at 40°C for 5 min using methanol/water (90:10, v/v) as the extracting solvent. Electrophoretic separation was achieved within 15 min using an uncoated fused‐silica capillary (50 μm internal diameter and 27.7 cm effective length) and a 500 mM Tris buffer containing 45% v/v methanol (titrated to pH^* 2.86 with H₃PO₄). The developed method was successfully applied to the quantification of seven alkaloids in Corydalis decumbens obtained from different regions of China. The combination of microwave‐assisted extraction with capillary electrophoresis was an effective method for the rapid analysis of the alkaloids in Corydalis decumbens .     

Hydrophobic ionic liquid‐based ultrasound‐assisted extraction of magnolol and honokiol from cortex Magnoliae officinalis

The hydrophobic ionic liquid of [BMIM][PF₆] was successfully used for the ultrasound‐assisted extraction of hydrophobic magnolol and honokiol from cortex Magnoliae officinalis. To obtain the best extraction efficiencies, some ultrasonic parameters including the concentration of [BMIM][PF₆], pH, ultrasonic power and ultrasonic time were evaluated. The results obtained indicated that the [BMIM][PF₆]‐based ultrasound‐assisted extraction efficiencies of magnolol and honokiol were greater than those of the [BMIM][BF₄]‐based ultrasound‐assisted extraction (from 48.6 to 45.9%) and the traditional ethanol reflux extraction (from 16.2 to 13.3%). Furthermore, the proposed extraction method is validated by the recovery, correlation coefficient (R²) and reproducibility (RSD, n=5), which were 90.8–102.6, 0.9992–0.9998, and 1.6–5.4%, respectively.     

Rapid extraction and analysis method for the simultaneous determination of 21 bioflavonoids in Siegesbeckia pubescens Makino

A novel and rapid microwave extraction and ultra high performance liquid chromatography coupled with a triple quadrupole‐linear ion trap mass spectrometry method was developed and validated for the determination of 21 bioflavonoids in Siegesbeckia pubescens Makino. The optimal conditions for the extraction of flavonoids from Siegesbeckia pubescens Makino involved the use of methanol as the extraction solvent, a microwave temperature of 70°C, an extraction time of 11 min, and a solvent‐to‐solid ratio of 40 mL/g. Chromatographic separation was achieved on a Waters ACQUITY UPLC BEH C₁₈ column(100 × 2.1 mm, 1.7 μm) with a gradient mobile phase (A: 0.3% v/v aqueous formic acid and B: acetonitrile) at a flow rate of 0.25 mL/min. All calibration curves showed good linearity (r > 0.999) within the test ranges. The method developed was validated with acceptable sensitivity, intra‐ and interday precision, reproducibility, and extraction recoveries. The validated method was successfully applied to determine the contents of 21 bioflavonoids in Siegesbeckia pubescens Makino from different sources.     

Liquid–liquid extraction of Cu(II), Co(II) and Ni(II) with salicylidèneaniline from sulphate media

For a fundamental study on the development of novel extraction divalent metal, the extraction behaviour of copper(II), cobalt(II) and nickel(II) is studied with salicylidèneaniline (SAN). The phenol group in the Schiff base moiety leads to a large increase in the percentage of transition metal ions. SAN has both good reactivity towards metal ions and solubility in organic solvents. The solvent extraction of copper(II), cobalt(II) and nickel(II) with salicylidèneaniline from sulphate media is studied with the following parameters: pH, concentration of the extractant and the nature of diluent. The stoichiometry coefficients of the extracted species are determined by the slope analysis method. The extraction reaction proceeds by cation exchange mechanism and the extracted species are: CuL₂HL, CoL₂HL and NiL₂. The extaction constants are evaluated for the different diluents. Under suitable conditions of pH, the solvent extraction of cobalt(II) and nickel(II) in different diluents leads to third phase formation. This tendency is confirmed from numerical extraction constants for both metal cations (log?K _ex?=??15.10?±?0.03 for nickel(II) in CHCl₃) and (log?K _ex?=??12.56?±?0.04 for cobalt(II) in CHCl₃). The extraction efficiency is found to follow the order Cu(II)?>?Co(II)?>?Ni(II).     

Temperature‐controlled ionic liquid‐dispersive liquid‐phase microextraction for preconcentration of chlorotoluron,diethofencarb and chlorbenzuron in water samples

This article describes a new, rapid and sensitive method for the determination of chlorotoluron, diethofencarb and chlorbenzuron from water samples with temperature‐controlled ionic liquid‐dispersive liquid‐phase microextraction. In the preconcentration procedure, ionic liquid 1‐hexyl‐3‐methylimidazolium hexafluorophosphate [C₆MIM] [PF₆] was employed as the extraction solvent. The parameters, such as volume of [C₆MIM] [PF₆], sample pH, extraction time, centrifuging time, temperature and salting‐out effect, were investigated in detail. Under the optimal extraction conditions, it has been found that three analytes had excellent LODs (S/N=3) in the range of 0.04–0.43 μg/L. The RSDs (n=6) were in the range of 1.3–4.7%. The proposed method was evaluated with lake water, tap water and melted snow water samples. The experimental results indicated that the proposed method had excellent prospect and would be widely used in the future.     

Ionic liquid‐based ultrasound‐assisted extraction of fangchinoline and tetrandrine from Stephaniae tetrandrae

An ionic liquid‐based ultrasound‐assisted extraction method has been developed for the effective extraction of fangchinoline and tetrandrine from Stephaniae tetrandrae. The effects of some ultrasound‐assisted extraction parameters including the concentration of [BMIM][BF₄], pH, ultrasonic power and time were investigated to optimize the ultrasound‐assisted extraction conditions. Compared to the regular ultrasound‐assisted extraction and traditional refluent extraction, the proposed [BMIM][BF₄]‐based ultrasound‐assisted extraction offered shorter extraction times (from 6 h to 40 min) and remarkable higher efficiencies (approximately 30% improved), which supported the suitability of the proposed approach. In addition, the proposed approach was confirmed by the good correlation coefficient (R²), recovery and reproducibility (RSD, n = 5), which were in the range of 0.9992–0.9995, 85.5–101.1%, and 1.87–4.33%, respectively.     

Dispersive solid–liquid phase microextraction based on nanomagnetic Preyssler heteropolyacid: A novel method for the preconcentration of nortriptyline

In this study, a new, simple, rapid, and efficient method combined with ultraviolet visible spectrophotometry and high‐performance liquid chromatography analysis was developed for the extraction and determination of nortriptyline. The tendency of the Preyssler tungsten heteropolyacid, H₁₄[NaP₅W₃₀O₁₁₀], immobilized on the surface of mesoporous nanomagnetite to adsorb the drug from the solution has been investigated. This method involves the use of an appropriate mixture of nanosorbent that was homogenized in disperser solvent (1.0 mL, ethanol). At first, the mixture containing the nanomagnetic sorbent and disperser solvent was injected into the aqueous sample, and a cloudy solution was formed. Subsequently, separation of the two phases was carried out using a magnet. In the second stage, analyte was desorbed from the sorbent by methanol as the optimal desorption solvent using sonication method. The elution solvent containing enriched analyte was introduced to the instruments for further analysis. Optimization of experimental conditions with respect to the extraction efficiency was investigated. The method was linear in the range of 25–5000, while the detection limit (LOD = 3S_B/m) was 7.9 ng/mL and the limit of quantification (LOQ = 10S_B/m) was 26.4 ng/mL. The relative standard deviation was 4.66%. The method was successfully applied to human hair samples.     

Quick and selective extraction of Z‐ligustilide from Angelica sinensis using magnetic multiwalled carbon nanotubes

A facile and highly efficient magnetic solid‐phase extraction method has been developed for Z‐ligustilide, the major therapeutic agent in Angelica sinensis. The solid‐phase adsorbent material used was prepared by conjugating carbon nanotubes with magnetic Fe₃O₄ nanoparticles via a hydrothermal reaction. The magnetic material showed a high affinity toward Z‐ligustilide due to the π–π stacking interaction between the carbon nanotubes and Z‐ligustilide, allowing a quick and selective exaction of Z‐ligustilide from complex sample matrices. Factors influencing the magnetic solid‐phase extraction such as the amount of the added adsorbent, adsorption and desorption time, and desorption solvent, were investigated. Due to its high extraction efficiency, this method was proved highly useful for sample cleanup/enrichment in quantitative high‐performance liquid chromatography analysis. The proposed method had a linear calibration curve (R² = 0.9983) over the concentration between 4 ng/mL and 200 μg/mL Z‐ligustilide. The accuracy of the method was determined by the recovery, which was from 92.07 to 104.02%, with the relative standard deviations >4.51%.     

Coupled solid phase extraction–supercritical fluid extraction–on-line gas chromatography of explosives from water

A method has been developed for the quantitative extraction of nitrotoluenes (2,3-dinitrotoluene, 2,4-dinitrotoluene and trinitrotolugene) from water using a Bakerbond^TM phenyl sorbent. The average solid phase extraction recoveries for spiked standards ranged from 80 to 95 percent for reagent water and 52 to 95 percent from well and surface water in the low ppb and ppt levels. After the nitrotoluenes had been trapped on the solid sorbent they were quantitatively eluted using SFE. Adding toluene to the extraction cell increased the rate of extraction, but did not improve analyte recovery versus unmodified CO₂. The extracts were analyzed off-line with GC–ECD using an internal standard. Extraction losses were due to analyte breakthrough, and not from poor SFE recoveries. This demonstrates that supercritical fluid extraction is a suitable elution technique for analytes trapped on solid phase extraction sorbents. Also, a method for the direct on-line coupling of SPE to GC, using SFE, has been developed and evaluated. Supercritical CO₂ is ideal for directly coupling SPE to GC, since carbon dioxide is a gas under ambient conditions. One potential problem of on-line SPE–SFE–GC is the presence of residual water trapped on the active sites of the Bakerbond¹³ phenyl sorbent. This problem was dealt with by using a split interface previously described by Hawthorne. From the results of this study, the relative standard deviation of the on-line SPE–SFE–GC interface was determined to be between 4 and 10 percent. In addition, there was no significant difference in the precision of the method with or without the use of an internal standard. A calibration curve was also constructed (r² = 0.995) from spiked controls, demonstrating that the method is quantitative.     

Optimization of microwave‐assisted extraction for six inorganic and organic arsenic species in chicken tissues using response surface methodology

Response surface methodology was applied to optimize the parameters for microwave‐assisted extraction of six major inorganic and organic arsenic species (As(III), As(V), dimethyl arsenic acid, monomethyl arsenic acid, p‐arsanilic acid, and roxarsone) from chicken tissues, followed by detection using a high‐performance liquid chromatography with inductively coupled mass spectrometry detection method, which allows the simultaneous analysis of both inorganic and organic arsenic species in the extract in a single run. Effects of extraction medium, solution pH, liquid‐to‐solid ratio, and the temperature and time of microwave‐assisted extraction on the extraction of the targeted arsenic species were studied. The optimum microwave‐assisted extraction conditions were: 100 mg of chicken tissue, extracted by 5 mL of 22% v/v methanol, 90 mmol/L (NH₄)₂HPO₄, and 0.07% v/v trifluoroacetic acid (with pH adjusted to 10.0 by ammonium hydroxide solution), ramping for 10 min to 71°C, and holding for 11 min. The method has good extraction performance for total arsenic in the spiked and nonspiked chicken tissues (104.0 ± 13.8% and 91.6 ± 7.8%, respectively), except for the ones with arsenic contents close to the quantitation limits. Limits of quantitation (S/N = 10) for As(III), As(V), dimethyl arsenic acid, monomethyl arsenic acid, p‐arsanilic acid, and roxarsone in chicken tissues using this method were 0.012, 0.058, 0.039, 0.061, 0.102, and 0.240 mg/kg (dry weight), respectively.     

Crown Ethers as Synergist in the 2-Thenoyltrifluoroacetone Extraction of Lanthanoids in 1,2-Dichloroethane

Summary. The solvent extraction of 14 trivalent lanthanoid ions (Ln ³⁺) from a nitrate medium into 1,2-dichloroethane containing 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione (HTTA) was investigated at 25.0°C. The extraction of Ln(TTA)₃ species was confirmed and the extraction constants were determined. The extraction of Ln with the synergistic mixture of HTTA and a crown ether (CE: 12-crown-4, 18-crown-6, cyclohexano-18-crown-6 or benzo-18-crown-6) was also investigated at 25.0°C. The 1:1 adducts of the complex and crown ether, Ln(TTA)₃·(CE) are formed for all the lanthanoid ions and the CEs used in this study. The formation constants, β_add, of the adduct Ln(TTA)₃·(CE) from Ln(TTA)₃ in the organic phase were determined by nonlinear least-squares method. The stabilities and structures of the formed adducts were discussed with respect to the cavity size, steric effect, and basicity of the CE.     

Ultrahigh-pressure supercritical fluid extraction and chromatography of Moringa oleifera and Moringa peregrina seed lipids

An ultrahigh-pressure supercritical fluid extraction method was optimized and applied to extract seed oil lipids from two moringa species, namely Moringa oleifera (MO) and Moringa peregrina (MP). A full-factorial design was used to investigate the direct and interaction influence of pressure and temperature in the range of 40 to 80 MPa and 40 to 70 °C, respectively, on the extracted amount of oil from crushed seeds. The results revealed that pressure has a significant positive influence on the extracted amount of oil. The best extraction condition using neat CO₂ was found at 80 MPa and 57 °C, yielding 396 ± 23 and 529 ± 26 mg oil per gram of seeds for MO and MP, respectively. An extraction kinetics study revealed a mainly solubility-controlled extraction of oil, and 28 g of CO₂ was required to extract 400 mg of oil per gram of seeds of MO using the developed method. Addition of ethanol to the sample prior to the extraction increased the proportion of extractable polar lipids as well as the total amount of extracted oil. The developed method increased the extracted amount of oil twofold compared to a reference method based on solvent sonication. The obtained oil consisted mainly of glycerolipids, sterol esters, and phospholipids. Phospholipids, campesterol, and stigmasterol ester concentrations were found to be higher in MO while cholesterol ester was more abundant in MP.

     

Layered double hydroxides: a novel nano-sorbent for solid-phase extraction

The nickel–aluminum layered double hydroxide (Ni–Al LDH) was synthesized by a simple co-precipitation method with controlled pH and followed by hydrothermal treatment. The obtained nano-structured inorganic material was employed, for the first time, as a new solid-phase extraction (SPE) sorbent for the extraction and pre-concentration of trace levels of fluoride ions from aqueous solutions. An indirect method was used for monitoring of extracted fluoride ions. The method is based on the quenching effect of extracted fluoride ions upon the fluorescence intensity of Al–oxine complex via the forming of AlF₆³⁻, which was determined spectrofluorometrically at λ_em = 510 nm with excitation at λ_ex = 404 nm. The effect of several parameters such as type of interlayer anion in Ni–Al LDH structure, pH, sample flow rate, elution conditions, amount of nano-sorbent, sample volume and co-existing ions on the extraction efficiency of the analyte were investigated. The results showed that fluoride ions could be retained on the Ni–Al (NO₃⁻) LDH at pH 6.0 and stripped by 1.2 mL of 3.0 mol L⁻¹ NaOH. In the optimum experimental conditions, the limit of detection (3 s) and enrichment factor were 9.0 ng mL⁻¹ and 50, respectively. The optimized method was successfully applied to the determination of fluoride concentration in various water samples. The results obtained from the proposed method were successfully compared with those provided by standard SPADNS method.