Application of ion-imprinted polymer synthesized by precipitation polymerization as an efficient and selective sorbent for separation and pre-concentration of chromium ions from some real samples

In this study, a new Cr(III)-imprinted polymer (Cr(III)-IIP) is prepared from CrCl₃·6H₂O, methacrylic acid functional monomer, ethyleneglycoldimethacrylate cross-linking agent, 2,2?-azobisisobutyronitrile radical initiator and 2,2-(azanediylbis (ethane-2,1-diyl))bis(isoindoline-1,3-dione) ligand. To obtain the maximum adsorption capacity, the optimum condition was studied through pH, type and concentration of eluent, IIP weight, sample volume as well as the adsorption and desorption times. The Cr(III) ion content was determined via flame atomic absorption spectrometer. In optimum conditions, the adsorption capacity of the IIP for Cr(III) was obtained to be 74.65 mg g^?1, using 50 mg of IIP and the initial pH solution of 3.0. Both the adsorption and desorption times for quantitative analyses of Cr(III) ions were 15 and 5 min; respectively. After elution of the adsorbed ions by 3 mL of 4 mol L^?1 HNO₃ aqueous solution, the established IIP-based SPE procedure provides a reasonable pre-concentration factor of 100. The IIP-based pre-concentration method provides a low detection limit of 1.7 µg L^?1 with good repeatability (RSD?=?3.22%). Reusability studies confirmed that synthesis IIP is reusable and recoverable up to six cycles. According to the selectivity experiments, it was concluded that the prepared sorbent possesses more affinity toward Cr(III) ions than other ions such as Al³⁺, Pb²⁺, Cu²⁺, Mn²⁺, Fe²⁺, Zn²⁺, and Ni²⁺ ions. To evaluate the potential applicability of the proposed separation method, the pre-concentration and determination of trace amounts of Cr(III) were performed successfully in food samples with complex matrices, a bestial sample (i.e. cow liver) and an herbal product (i.e., broccoli) as real samples.     

Double-imprinted polymer based on cross-linked poly(vinylimidazole–trimethylolpropane trimethacrylate) in solid phase extraction for determination of lead from wastewater samples by UV–vis spectrophotometry

The monitoring of the heavy metal pollution in wastewater is increasingly becoming a crucial global issue since they tend to accumulate in food chains and can cause many biological abnormalities. In this work, it was developed a novel lead ion-imprinted polymer (IIP) using sodium dodecyl sulphate (SDS) as a second template to be used as adsorbent in solid phase extraction (SPE) for determination of lead from wastewater samples by UV–vis spectrophotometry. The polymer called IIP–SDS was synthesised by a double-imprinting process with lead (template) and SDS (template). IIP–SDS was characterised by infrared spectroscopy Fourier transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. IIP–SDS showed good recovery for lead (around 82.0%), while the IIP (only lead as template) was 72.2% and non-IIP was 44.9%. Thus, the double-imprinting process for the preconcentration of Pb²⁺ proved to be a more adequate methodology than IIP with a single template. The optimised parameters of sample preparation were washing solvent (2.0 mL of tetrahydrofuran), type and volume of eluent (5 mL of 1 mol L^?1 hydrochloric acid), sample amount (30 mL of water spiked with 10.0 µg mL^?1), amount of IIP–SDS (400 mg) and sample pH (pH = 4.5). Linearity ranged from 10 to 125 µg L^?1 with r > 0.992. The limit of detection and quantification were 6.3 and 10 µg L^?1, respectively. The precision (relative standard deviation, %) and accuracy (relative error, %) were lower than 15%. Finally, IIP–SDS may be an alternative and effective adsorbent for SPE procedures in monitoring of wastewater samples.     

Synthesis and characterisation of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) Zr(IV) monothiophosphate composite cation exchanger: analytical application as lead ion selective membrane electrode

A Pb²⁺ ion selective membrane electrode based on poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) Zr(IV) monothiophosphate composite cation exchange material was fabricated using solution casting method. The effect of membrane composition on the proton exchange capacity was investigated by using varying amounts of electroactive material. The membrane with 250 mg of electroactive material and 10 µL of plasticiser exhibited higher proton conductivity. The optimised membrane composition was used for the fabrication of ion selective membrane electrode which exhibited typical Nernstian response towards Pb²⁺ ions in the concentration range 20.70 gL^?1–20.7 µgL^?1 (1 × 10^–1–1 × 10^–7 mol L^?1) with a sub-Nernstian slope of 27.429 mV per decade change in Pb²⁺ ion concentration. The response time of the electrode under study for Pb²⁺ ions was found to be 11 s and the electrode can be used for 120 days without any considerable divergence in response potential. It can also be successfully used in the pH range from 3.0 to 6.5. It was found selective for Pb²⁺ ions in the presence of various monovalent, divalent and trivalent interfering metal ions. It was also employed as an indicator electrode in the potentiometric titration of Pb²⁺ ions using ethylenediaminetetraacetic acid, disodium salt, as a titrant.     

Potentiometric sensor for the nanoscale monitoring of Ni2+ ion in environmental samples by the fabrication of coated pyrolytic graphite electrode based on a novel C–C-coupled compound

Novel ligand 5,5?-((3-nitrophenyl)methylene)bis(2,6-diaminopyrimidin-4(3H)-one) (L) was synthesised and characterised. Preliminary studies on L have showed that it has more affinity towards the Ni²⁺ ion. Thus, the L was used as the electroactive material in the fabrication of poly(vinyl chloride) (PVC)-based membrane sensors such as coated graphite electrode (CGE) and coated pyrolytic graphite electrode (CPGE). Several polymeric membranes were fabricated by incorporating L as ionophore, NaTPB as anion excluders and BA, 1-CN, DBP, DOP and o-NPOE as solvent mediators and their effect on potentiometric response studied. Comparative electroanalytical studies performed on the CGE and CPGE depict that the CPGE with optimised membrane composition of L:PVC:o-NPOE:NaTPB in the ratio of 7:33:58:2 (w/w, mg) exhibited the best response in terms of wide working concentration range from 2.0 × 10^?8 to 1.0 × 10^?1 mol L^?1, (3.64 µg L^?1 –18.2 g L^?1) lower detection limit of 8.1 × 10^–9 mol L^?1 (1.47 µg L^?1) with Nernstian compliance of 29.4 ± 0.2 mV decade^?1 of activity of Ni²⁺ ion in the pH range of 3.5–9.0. The sensor can work satisfactorily in water–acetonitrile and water–methanol mixtures. It can tolerate 30% acetonitrile and 20% methanol content in the mixtures. The sensor showed fast response time of 8 s and could be used successfully for a period of 4 months. The sensor reflects its utility in the quantification of Ni²⁺ ion in real samples and has been successfully employed as an indicator electrode in the potentiometric titration of Ni²⁺ ion with EDTA.     

Development of a new analytical method for Pb preconcentration and its further determination in water and foodstuffs using relatively low-sensitivity flame atomic absorption spectrometry

The present study describes chelation of Pb(II) with ascorbic acid and formation of a charge-transfer sensitive ion-pair in the presence of Rhodamine 6G at pH 5.5, and then its extraction to the micellar phase of non-ionic surfactant, PONPE 7.5 by an ultrasound-assisted cloud point extraction method before analysis by FAAS. The various variables affecting ion-pair formation and extraction efficiency were studied and optimised. Under the optimised conditions, the good linear relationships in the ranges of 0.4–150 μg L^?1 and 0.8–120 μg L^?1 for solvent-based calibration and matrix-matched calibration curves, respectively, were achieved with a pre-concentration factor of 71.4 from pre-concentration of 50-mL sample. Moreover, the limits of detection with good sensitivity enhancements of 124 and 114.5 were 0.13 and 0.24 μg L^?1, respectively, while the intra-day and inter-day precision (as RSD%, for five replicate measurements of 5 and 100 μg L^?1 in the same day and three succeed days) were in range of 2.8–5.4% and 3.7–6.3%, respectively. The matrix effect on triplicate determination of 50 µg L^?1 Pb(II) was also investigated. The accuracy of the method was statistically verified by the analysis of two certified reference materials (CRMs) after digestion with acid mixtures (HNO₃-H₂O₂-HF and HNO₃-H₂O₂) and dilution at suitable ratios. It has been observed that there is statistically not a significant difference between the certified- and found-values. The accuracy was also controlled using the pre-treated sample solutions spiked at different concentration levels, and the good spiked recoveries were obtained in range of 90–102.8%. The method was successfully applied to the determination of trace amounts of lead in water and food matrices with satisfactory results.     

Facile and Simultaneous Stripping Determination of Zinc,Cadmium and Lead on Disposable Multiwalled Carbon Nanotubes Modified Screen‐Printed Electrode

Screen‐printed electrodes (SPEs) are cheap and disposable. But their application for heavy metal detection is limited due to the low sensitivity and poor selectivity. Here we report the ultrasensitive and simultaneous determination of Zn²⁺, Cd²⁺ and Pb²⁺ on a multiwalled carbon nanotubes and Nafion composite modified SPE with in situ plated bismuth film (MWCNTs/NA/Bi/SPE). The linear curves range from 0.5–100 µg L^?1 for Zn²⁺ and 0.5–80 µg L^?1 for Cd²⁺. Uniquely, the linear curve for Pb²⁺ ranges from 0.05–100 µg L^?1 with a detection limit of 0.01 µg L^?1. The practical application was verified in real samples with satisfactory results.     

Sensitive Stripping Determination of Cadmium(II) and Lead(II) on Disposable Graphene Modified Screen‐Printed Electrode

In the present work, a sensitive, facile and disposable sensing platform for trace analysis of heavy metal ions was developed at the Bi modified graphene‐poly(sodium 4‐styrenesulfonate) composite film screen printed electrode (GR/PSS/Bi/SPE). The GR/PSS/Bi/SPE improved sensitivity and linearity due to the functionalization of graphene with negatively charged PSS providing more absorbing sites. The detection limit of the GR/PSS/Bi/SPE is found to be 0.042 µg L^?1 for Cd²⁺ and 0.089 µg L^?1 for Pb²⁺ with linear responses of Cd²⁺ and Pb²⁺ in the range of 0.5–120 µg L^?1. Finally, the practical application was confirmed in real water with satisfactory results.     

Preconcentration of Pb2+ by iron oxide/amino-functionalized silica core–shell magnetic nanoparticles as a novel solid-phase extraction adsorbent and its determination by flame atomic absorption spectrometry

The use of iron oxide/amino-functionalized silica core–shell magnetic nanoparticles for preconcentration of Pb²⁺ followed by its consecutive atomic absorption spectrometry determination is described. Effects of various operating variables, namely, solution pH, initial Pb²⁺ concentration, contact time, adsorbent dosage, sample volume, concentration and volume of desorbing solution, and co-existing ions on solid-phase extraction (SPE) of Pb²⁺ were studied by batch equilibrium technique. The experimental adsorption data were well fitted to the Langmuir isotherm model. The Langmuir adsorption capacity and equilibrium time were found to be 100 mg g^?1 and 20 min, respectively. The adsorption data were also fitted to kinetic pseudo-first-order and pseudo-second-order models. Kinetic studies showed that the adsorption followed pseudo-second-order model. Under the optimal SPE conditions, the enrichment factor, detection limit and relative standard deviation for determination of Pb²⁺ were found to be 211, 1 μg L^?1, and 3.7 % for 50 μg L^?1, respectively. The proposed method was successfully applied to the determination of lead in a real sample with satisfactory results.     

Speciation and determination of chromium ions by dispersive micro solid phase extraction using magnetic graphene oxide followed by flame atomic absorption spectrometry

A selective, simple and fast dispersive micro solid phase extraction method using magnetic graphene oxide (GO) as an efficient sorbent has been developed for the extraction, separation and speciation analysis of chromium ions. The method is based on different adsorption behaviour of Cr(VI) and Cr(III) species onto magnetic GO in aqueous solutions which allowed the selective separation and extraction of Cr(VI) in the pH range of 2.0–3.0. The retained Cr(VI) ions by the sorbent were eluted using 0.5 mL of 0.5 mol L^?1 nitric acid solution in methanol and determined by ?ame atomic absorption spectrometry. Total chromium content was determined after the oxidation of Cr(III) to Cr(VI) by potassium permanganate. All effective parameters on the performance of the extraction process were thoroughly investigated and optimised. Under the optimised conditions, the method exhibited a linear dynamic range of 0.5–50.0 µg L^?1 with a detection limit of 0.1 µg L^?1 and pre-concentration factor of 200. The relative standard deviations of 3.8% and 4.6% (n = 8) were obtained at 25.0 µg L^?1 level of Cr(VI) for intra- and inter-day analysis, respectively. The method was successfully applied to the speciation and determination of Cr(VI) and Cr(III) in environmental water samples.     

Square-Wave Anodic Stripping Voltammetry (SWASV) for the Determination of Ecotoxic Metals,Using a Bismuth-Film Electrode

This article reviews the use of square wave anodic stripping voltammetry for the simultaneous determination of ecotoxic metals (Pb, Cd, Cu, and Zn) on a bismuth-film (BiFE) electrode. The BiFE was prepared in situ on a glassy-carbon electrode (GCE) from the 0.1 mol L^?1 acetate buffer solution (pH 4.5) containing 200 µg L^?1 of bismuth (III). The addition of hydrogen peroxide to the electroanalytical cell proved beneficial for the interference-free determination of Cu (II) together with zinc, lead, and cadmium, using the BiFE. The experimental variables were investigated and optimized with the view to apply this type of voltammetric sensor to real samples containing traces of these metals. The performance characteristics, such as reproducibility, decision limit (CC_a), detection capability (CC_β), sensitivity, and accuracy indicated that the method holds promise for trace Cu²⁺, Pb²⁺, Cd²⁺, and Zn²⁺ levels by employment of Hg-free GCE with SWASV. CCa, and CCβ were calculated according to the Commission Decision of 12 August 2002 (2002/657/EC). Linearity was observed in the range 20–280 µg L^?1 for zinc, 10–100 µg L^?1 for lead, 10–80 µg L^?1 for copper, and 5–50 µg L^?1 for cadmium. Using the optimized conditions, the stripping performance of the BiFE was characterized by low limits of detection (LOD). Finally, the method was successfully applied in real as well as in certified reference water samples.     

Multivariate Analysis for the Classification Differentiation of Brazilian Sugarcane Spirits by Analysis of Organic and Inorganic Compounds

Abstract

Brazilian sugarcane spirits were analyzed to elucidate similarities and dissimilarities by principal component analysis. Nine aldehydes, six alcohols, and six metal cations were identified and quantified. Isobutanol (LD 202.9 µg L^?1), butiraldehyde (0.08–0.5 µg L^?1), ethanol (39–47% v/v), and copper (371–6068 µg L^?1) showed marked similarities, but the concentration levels of n-butanol (1.6–7.3 µg L^?1), sec-butanol (LD 89 µg L^?1), formaldehyde (0.1–0.74 µg L^?1), valeraldehyde (0.04–0.31 µg L^?1), iron (8.6–139.1 µg L^?1), and magnesium (LD 1149 µg L^?1) exhibited differences from samples.     

Simultaneous voltammetric analysis of lead,copper and mercury ions by carbon paste electrode based on 1-(3-aminopropyl) imidazole modified polymer

In this study, a carbon paste electrode modified with a novel 1-(3-aminopropyl) imidazole functionalised crosslinked chlorosulfonated poly(styrene)-divinyl benzene polymer was used for selective and sensitive determination of the trace amounts of Pb²⁺, Cu²⁺ and Hg²⁺ ions by square wave anodic stripping voltammetry. The effect of some parameters such as paste composition, pH, preconcentration time, reduction potential and time, type of supporting electrolyte and potential scan rate on the determination of metal ions were investigated to find the optimal conditions. The effective open-circuit accumulation of the studied metal ions was succeeded only by the modification of the carbon paste electrode with functional polymer. For 6 min open-circuit preconcentration, the detection limit of Pb²⁺, Cu²⁺ and Hg²⁺ was found to be 5, 9 and 14 µgL^?1, respectively at 100 mVs^?1. The results confirmed that the lower concentration levels of these trace metal ions can be determined with the increase of preconcentration time and/or potential scan rate. Good detection limits and large dynamic concentration ranges were also obtained for their binary and ternary mixtures. The optimised method was successively applied to determine the concentration of Pb²⁺, Cu²⁺ ions in the tap water sample and Cu²⁺ ion in the waste water sample in the presence of possible interfering species (RSD<1%, recoveries 96–110% for 4 min preconcentration).     

Dispersive Liquid–Liquid Microextraction of Silver Prior to Determination by Microsample Introduction-Flame Atomic Absorption Spectrometry

Abstract

A new simple and sensitive method has been proposed for rapid determination of trace levels of silver in environmental water samples, using dispersive liquid–liquid microextraction (DLLME) prior to its microsample introduction-flame atomic absorption spectrometry. Under the optimum conditions, the linear range was 0.1–7 µg L^?1 and limit of detection was 0.018 µg L^?1. The relative standard deviation for 0.50 and 5.00 µg L^?1 of silver in water sample was 4.0 and 1.7%, respectively. The relative recoveries of silver from tap, well, river, and seawater samples at spiking levels of 1.00 and 5.00 µg L^?1 were in the range of 86.4–98.6%.     

Applications of a Novel Sample Preparation Method for the Determination of Sulfonamides in Edible Meat by CZE

A simple, rapid and reliable method based on SPE clean-up and CZE separation was validated for the trace determination of sulfonamides (SAs) in meat. Acetonitrile was used for the extraction of SAs (sulfamethoxazole, sulfamethazine, sulfamerazine, and sulfadimethoxine) from the samples and 1-propanol was used for the denaturing of the proteins present in the sample matrix. SPE procedure was employed for the clean-up and pre-concentration of SAs prior to CZE analysis. Complete separation was achieved by using 45 mmol L^?1 phosphate buffer (pH = 6.3) at an applied voltage of 20 kV. Overall obtained recoveries were from 83.3 to 94.5% for the SAs. The detection limit of each sulfonamide ranges from 4 to 6 μg kg^?1. The presented one step SPE clean-up method is highly applicable for the determination of the SAs at a residue level below the maximum residue limit.     

Simultaneous spectrophotometric determination of iron species using orthogonal signal correction–generalized partial least squares calibration method after vortex-assisted dispersive liquid–liquid microextraction

A vortex-assisted dispersive liquid–liquid microextraction method in combination with UV–Vis spectrophotometry was developed for the simultaneous extraction and determination of iron species. In this method, Fe²⁺ and Fe³⁺ were complexed with pyridine-2-amidoxime, neutralized through ion pair formation with sodium dodecyl sulfate, and extracted into the fine droplets of chloroform. After centrifugation, the absorbance of the extracted complexes was recorded in the wavelength range of 360–700 nm. The parameters affecting the extraction efficiency such as the pH, the type and volume of the extraction solvent, ligand concentration, and sample volume were optimized. The individual iron species was then determined by means of the orthogonal signal correction–generalized partial least squares method. Under the optimized conditions, the calibration curves were linear over the range of 2.0–100 and 3.0–200 µg L^?1 with detection limits of 0.4 µg L^?1 for Fe²⁺ and 0.8 µg L^?1 for Fe³⁺, respectively. The relative standard deviations for intra- and inter-day assays (n = 5) were 2.3 and 4.0 for Fe²⁺ at 50 µg L^?1 and 2.7 and 4.3 for Fe³⁺ at 30 µg L^?1, respectively. The enhancement factors of 77 and 69 were achieved for Fe²⁺ and Fe³⁺, respectively. The proposed method was successfully applied to the determination of iron species in water samples.     

A new sensitive and selective sensor for heavy metal ions based on tannin extracted from the skin of Punica granatum L

This article presents the development of a sensor made from a gold electrode and a receiving polymeric membrane based on tannin extracted from the skin of Punica granatum. L (pomegranate) for real-time detection of heavy metals in a hydrous environment. The basic principle of this device is the complexing (chelating) of metal ions through the adjacent hydroxyl groups contained in the chemical structures of the tannins. The electrochemical characterisation was performed by using electrochemical impedance spectroscopy and square wave voltammetry. Other morphological and structural analyses were performed by using Fourier transform infrared spectroscopy and atomic-force microscopy. The results obtained showed the high sensitivity of the developed device (detection limits of 6.35 × 10^?9 g L^?1 for Cu²⁺, 1.1 × 10^?8 g L^?1 for Cd²⁺ and 2 × 10^?7 g L^?1 for Pb²⁺) and the possibility of simultaneously detecting several heavy metals, each one in a highly selective manner with highly acceptable response time (48s).     

SBA-15/Metformin as a novel sorbent combined with surfactant-assisted dispersive liquid–liquid microextraction (SA-DLLME) for highly sensitive determination of Pb,Cd and Ni in food and environmental samples

This paper established a new, rapid and sensitive method for the ultra-trace determination of lead, cadmium and nickel in food and environmental samples preconcentrated by dispersive solid-phase extraction (DSPE) combined with surfactant-assisted dispersive liquid–liquid microextraction (SA-DLLME) prior to graphite furnace atomic absorption spectrometry. SBA-15/Met was synthesized and used as a new efficient sorbent for the extraction of metal ions in DSPE. It was characterized by TEM and TGA techniques. After DSPE step, stripped metal elements were complexed with dithizone, and then, the complexes were extracted into carbon tetrachloride by using SA-DLLME. A conventional nonionic surfactant, triton X-100 was used as a disperser agent. Under the optimized conditions, the limit of quantifications was found to be 2.5 ng L^?1 for Pb²⁺, Cd²⁺ and 5.0 ng L^?1 for Ni²⁺. The limits of detection were 1.5 ng L^?1 for Ni²⁺ and 0.75 ng L^?1 for Pb²⁺ and Cd²⁺, with enrichment factor of 1650. The optimized method exhibited a good precision level with relative standard deviations (RSDs%) values of 4.9, 5.2 and 5.0% for 1 μg L^?1 Pb²⁺, Cd²⁺ and Ni²⁺, respectively (n = 7). Application of the proposed method to the analysis of fish-certified reference material produced results that were in good agreement with the certified values.     

Ion Chromatography with Post-column Reaction and Serial Conductivity and Spectrophotometric Detection Method Development for Quantification of Transition Metal Dissolution in Lithium Ion Battery Electrolytes

We present a method for the separation and determination of transition metals in electrolytes based on ion chromatography (IC) with post-column reaction (PCR) and serial conductivity and spectrophotometric detection. Three IC columns [Metrosep C4—250/4.0 (column A), Metrosep C6—250/4.0 (column B), and Nucleosil 100-5SA—250/4.6 (column C)] with different capacities, and stationary phases were used and compared with each other for method development. All spectrophotometric measurements were carried out with 4-(2-pyridylazo)resorcinol (PAR) as PCR reagent at a wavelength of 500 nm. To characterize the precision of the separation, the selectivity for the analysis of transition metals (nickel, cobalt, copper, and manganese) in the presence of large amounts of lithium and the resolution of the peaks were determined and compared with one another. Furthermore, the limits of detection (LOD) and quantification (LOQ) were determined for the transition metals. The LODs and LOQs determined by column C were as follows: cobalt (LOD/LOQ): 9.4 µg L^?1/31.3 µg L^?1, manganese (LOD/LOQ): 7.0 µg L^?1/23.5 µg L^?1, and nickel (LOD/LOQ): 6.3 µg L^?1/21.1 µg L^?1. Finally, the concentration of transition metal dissolution of the cathode material Li₁Ni_1/3Co_1/3Mn_1/3O₂ (NCM) was investigated for different charge cut-off voltages by the developed IC method.     

Selective extraction and preconcentration of ultra-trace amounts of arsenic(V) ions using carbon nanotubes as a novel sorbent

In the present study, multiwalled carbon nanotubes (MWCNTs) as solid phase extraction sorbent were developed for preconcentration of arsenic(V) species prior to graphite furnace atomic absorption spectrometry (GFAAS) determination. Arsenic(V) was selectively sorbed on the packed column with MWCNTs within a pH 9.5 in the presence of 2-(5-bromo-2-pyridylazo)-5-diethyl amino phenol (5-Br-PADAP). The adsorbed species was then desorbed with 1 mL of 2.0 M HNO₃. Experimental parameters including pH, sample volume and flow rate, type, volume and concentration of eluent that influence the recovery of the arsenic(V) species were optimised. Under the optimised conditions, the calibration curve was linear in the range of 0.2–10.0 µg L^?1 with detection limit of 0.016 µg L^?1. The relative standard deviations (RSD) for seven replicate determinations at 1.0 µg L^?1 level of arsenic was 6.69%. The proposed method was successfully applied to the determination of arsenic in water samples and certified reference material (NIST RSM 1643e).     

Use of ionic liquid based chitosan as sorbent for preconcentration of fluoroquinolones in milk,egg, fish,bovine, and chicken meat samples by solid phase extraction prior to HPLC determination

The possibility of using ionic liquid based chitosan sorbent for the separation and preconcentration of fluoroquinolone antibiotics (marbofloxacin, enoxacin, ofloxacin, ciprofloxacin, and enrofloxacin) has been studied. For this reason, different ionic liquids were prepared and coated on the chitosan sorbent. The conditions of the preconcentration of fluoroquinolones on a microcolumn have been optimized and the extraction efficiencies of the prepared sorbents have been compared. The compounds were eluted with 5 mL of 20% NH₃ (v/v, MeOH) solution and determined by HPLC with diode array and fluorescence detector. The limits of detection were found as 4.23 µ g L^?1 for marbofloxacin, and 1.09 µg L^?1 for enoxacin; 3.23 × 10^?3 µg L^?1 for ofloxacin; 8.39 × 10^?3 µg L^?1 for ciprofloxacin; and 19.50 × 10^?3 µg L^?1 for enrofloxacin. The developed method was applied for the analysis of fluoroquinolone in milk, egg, fish, bovine, and chicken samples and the recoveries were obtained in the range 70–100%.