Determination of nitrofurantoin, furazolidone and furaltadone in milk by high-performance liquid chromatography with electrochemical detection

Blue-emitting tryptophan-protected gold nanoclusters acted as a sensitive nanosensor for fluorescence sensing and visual imaging detection of furaltadone

Herein, blue-emitting gold nanoclusters (Au NCs) were carried out through tryptophan as the protecting and reducing agents. In aqueous solution of Au NCs@tryptophan, the addition of furaltadone guaranteed the interaction of furaltadone with tryptophan around Au NCs. The propinquity of furaltadone to Au NCs caused that the fluorescence of Au NCs was weakened by furaltadone based on the inner filter effect (IFE). Under the optimal measurement conditions, the logarithm of relative fluorescence intensity of Au NCs@tryptophan was linearly carried out with the furaltadone amount increasing from 0.5 to 100 μM, the corresponding detection limit was 0.087 μM. The fluorescence change of Au NCs@tryptophan displayed excellent selectivity and sensitivity for furaltadone than other possible substance in the human body. In view of Au NCs@tryptophan, the as-performed fluorescence nanosensor suggested outstanding ability for furaltadone sensing in real samples. Obviously, this nanoprobe of furaltadone could implement the naked-eye visual fluorescence determination of furaltadone.

One-step synthesis of blue emission copper nanoclusters for the detection of furaltadone and temperature

Polyvinyl pyrrolidone (PVP), playing roles as a templating agent, can be applied to prepare blue-emitting copper nanoclusters (Cu NCs@PVP) on the basis of a rapid chemical reduction synthesis method. The Cu NCs@PVP displayed a blue emission wavelength at 430 nm and the corresponding quantum yield (QY) could reach 10.4%. Subsequently, the as-synthesized Cu NCs@PVP were used for the trace analysis of furaltadone based on the inner filter effect (IFE) between Cu NCs@PVP and furaltadone, which caused the fluorescence to be effectively quenched. Additionally, this proposed determination platform based on the Cu NCs@PVP for furaltadone sensing possessed an excellent linear range from 0.5 to 100 μM with a lower detection limit of 0.045 μM (S/N = 3). Meanwhile, the Cu NCs@PVP also could be applied for the sensing of temperature. Furthermore, the practicability of the sensing platform has been successfully verified by measuring furaltadone in real samples, affirming its potential to increase fields for the determination of furaltadone.

A review on nanomaterial-based electrodes for the electrochemical detection of chloramphenicol and furazolidone antibiotics

To grow food for people, antibiotics were used, and these antibiotics can accumulate in the human body through food metabolism, which may have remarkably harmful effects on human health and safety. Therefore, low-cost sensors are needed for the detection of antibiotic residues in food samples. Recently, nanomaterial-based electrochemical sensors such as carbon nanoparticles, graphene nanoparticles, metal oxide nanoparticles, metal nanoparticles, and metal-organic nanostructures have been successfully used as sensing materials for the detection of chloramphenicol (CP) and furazolidone (FZ) antibiotics. However, additional efforts are still needed to fabricate effective multi-functional nanomaterial-based electrodes for the preparation of portable electrochemical sensor devices. The current review focuses on a quick introduction to CP and FZ antibiotics, followed by an outline of the current electrochemical analytical methods. In addition, we have discussed in-depth different nanoparticle supports for the electrochemical detection of CP and FZ in different matrices such as food, environmental, and biological samples. Finally, a summary of the current problems and future perspectives in this area are also highlighted.

Raspberry-like CuWO4 hollow spheres anchored on sulfur-doped g-C3N4 composite: An efficient electrocatalyst for selective electrochemical detection of antibiotic drug nitrofurazone

We report a highly selective and sensitive electrochemical sensor for the determination of nitrofurazone (NZ) based on sulfur-doped graphitic carbon nitride with copper tungstate hollow spheres (Sg-C₃N₄/CuWO₄). Here, a Sg-C₃N₄/CuWO₄ composite was synthesized by a facile ultrasonic method. The physicochemical properties of the composite were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). Then, the surface morphology of the composite material was investigated by field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM). Moreover, the electrochemical activity of the as-synthesized composite material was initially tested using electrochemical impedance spectroscopy (EIS). The electroanalytical techniques namely cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were carried out for the electrochemical studies. The proposed sensor exhibits lower LOD and good sensitivity of about 3 nM and 1.24 μAμM^-1 cm^-2 to NZ detection. In addition, the Sg-C₃N₄/CuWO₄ modified electrode showed excellent repeatability, reproducibility, long-term storage stability and excellent selectivity. The developed sensor was successfully applied for the determination of NZ in human urine and serum samples and achieved good recovery results.

Investigation of electrocatalytic and photocatalytic ability of Cu/Ni/TiO2/MWCNTs Nanocomposites for detection and degradation of antibiotic drug Furaltadone

In this manuscript, "Get two mangoes with one stone" strategy was used to study the electrochemical detection and photocatalytic mineralization of furaltadone (FLT) drug using Cu/Ni/TiO2/MWCNTs nanocomposites for the first time. The bi-functional nanocomposites were synthesized through a hydrothermal synthesis technique. The successfully synthesized nanocomposites were analyzed by various analytical techniques. The Cu/Ni/TiO2/MWCNTs nanocomposites decorated screen-printed carbon electrode (SPCE) exhibit a good electrocatalytic ability towards detection of FLT. Moreover, the electrocatalytic detection of FLT based on the nanocomposites decorated SPCE have high stability, lower detection limit, and excellent sensitivity of 0.0949 μM and 1.9288 μA μM-1 cm-2, respectively. In addition, the nanocomposites decorated SPCE electrodes performed in real samples, such as river water and tap water, the satisfactory results were observed. As UV-Visible spectroscopy revealed that the Cu/Ni/TiO2/MWCNTs nanocomposites had an excellent photocatalytic ability for degradation of FLT drug. The higher degradation efficiency of 75% was achieved within 45 min under irradiation of visible light. In addition, after the degradation process various intermediates are produced which is confirmed by GC-MS analysis. The excellent photocatalytic ability was improved to the dopant ions and restrictions of electron-hole pair.

A single method to analyse residues from five different classes of prohibited pharmacologically active substances in milk

In the European Union, the use of veterinary drugs belonging to the A6 group is prohibited in food-producing animals according to Commission Regulation (EU) No. 2010/37. The aim of this study was to improve the analytical control strategy by developing a single method to analyse residues of prohibited pharmacologically active substances in milk. For this, a single method was developed to analyse 16 prohibited pharmacologically active substances belonging to five different substance classes at required or recommended levels: nitroimidazoles at 3 μg kg^-1, nitrofurans at 0.5 μg kg^-1, chloramphenicol at 0.1 μg kg^-1, dapsone at 5 μg kg^-1 and chlorpromazine at 1 μg kg^-1. Milk sample preparation started with an acid hydrolysis combined with a derivatisation. These steps were followed by a clean-up consisting of a dispersive solid-phase extraction and a liquid-liquid extraction. Finally, the sample extracts were analysed by liquid chromatography combined with tandem mass spectrometry, operating alternately in the positive and negative mode. The method was fully validated according to Commission Decision 2002/657/EC for bovine milk and additionally validated for caprine milk. The validation proved that the method is highly effective to detect and confirm all 16 substances in bovine and caprine milk and, additionally to quantify 15 of these substances in bovine milk and 13 of these substances in caprine milk. This study resulted in a new multi-class method to detect, quantify and confirm the identity of 16 prohibited pharmacologically active substances belonging to five different substance classes in two types of milk.

Facile synthesis of Co(ii)-doped cobalt oxide nanostructures: their application in the sensitive determination of the prophylactic drug furazolidone

Electrochemical detection of prophylactic drug furazolidone through Co–Co₂O₄ modified GCE.

Determination of nitrofuran metabolites in marine products by high performance liquid chromatography–fluorescence detection with microwave-assisted derivatization

A sensitive method for simultaneous detection of four nitrofuran metabolites (3-amino-2-oxazolidinone (AOZ), semicarbazide (SEM), 3-amino-morpholinomethyl-2-oxazolidinone (AMOZ) and 1-aminohydantoin (AH)) in marine products.

Pyoverdine secreted by Pseudomonas aeruginosa as a biological recognition element for the fluorescent detection of furazolidone

Methods for the rapid and sensitive detection of furazolidone, a pesticide used for the treatment of infections of animals and human beings, have been urgently recommended for its large residual, strong carcinogenicity and genotoxicity in the environment. In this study, a method for the detection of furazolidone based on the rapid fluorescence quenching of pyoverdine by furazolidone was developed. Pyoverdine secreted by a Pseudomonas aeruginosa strain PA1 was purified through affinity chromatography and its fluorescent property was characterized. The fluorescence of pyoverdine could be quenched by furazolidone with specificity, and based on this phenomenon a fluorescent method for furazolidone detection was established. Fluorescence of pyoverdine was quenched by furazolidone probably due to the electron transfer from pyoverdine to furazolidone. The optimal pH for the detection was 7.2 in 50 mM 3-(N-Morpholino) propanesulfonic acid solution, and the whole detection process could be completed within a few seconds. The linear range of the detection was 2-160 µM and the limit of detection (LOD) was 0.5 µM. This study developed a novel fluorescent method for furazolidone detection, and the rapid and specific fluorescent biosensor can be potentially applied for furazolidone detection in the aquatic samples.

Multidetermination of four nitrofurans in animal feeds by a sensitive and simple enzyme-linked immunosorbent assay

In this study, the polyclonal antibody against furazolidone was produced with furazolidone coupling to protein carriers by a diazotization method and glutaraldehyde reaction, respectively. The antibody obtained showed good specificity toward furazolidone and various cross-reactivity toward nitrofurantoin, nitrofurazone, and furaltadone. Then, an indirect competitive enzyme-linked immunosorbent assay (ELISA) based on the antibody was first developed for multidetermination of four nitrofurans in animal feeds. The limit of detection (LOD) of the method was 0.2-2.1 ng/g depending on the component. After simple extraction, the fortified swine and broiler chicken feed samples were detected with recovery ranges of 75.9-86.4%. Results obtained from ELISA were confirmed by high-performance liquid chromatography (HPLC) with ultraviolet detection. Analysis of the unknown feed samples indicates that ELISA can be a practical tool for screening of nitrofurans in animal feeds before confirmation by HPLC.

Development of an indirect competitive ELISA for the detection of furazolidone marker residue in animal edible tissues

Due to its carcinogenicity and mutagenicity, furazolidone has been prohibited completely from being used in food animal production in the world since 1995. To monitor the illegal abuse of furazolidone, a polyclonal antibody-based indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was developed for the determination of tissue-bound furazolidone metabolite 3-amino-2-oxazolidone (AOZ). The highly specific antibody was targeted for PAOZ, the benzaldehyde derivative of AOZ. The 50% inhibition values (IC 50) of 0.91 microg/L for AOZ was achieved with the most sensitive antibody Ab-B1 by altering ELISA conditions. In the ELISA, sample extraction and cleanup were performed by an is MAX cartridge following combined hydrolysis of the tissue-bound AOZ and derivatization of the homogenized tissues with benzaldehyde. The limits of detection (LOD) calculated from the analysis of 20 known negative tissue samples (swine liver, swine muscle, chicken liver, chicken muscle,and fish muscle) were 0.3-0.4 microg/kg (mean+3 SD). Recoveries of AOZ fortified at the levels of 0.4, 1, and 5 microg/kg ranged from 55.8 to 96.6% in the tissues. The coefficients of variation were less than 20% over the range of AOZ concentrations studied. The linear detection range was between 0.1 and 25.6 microg/L. Validation of the ELISA method with swine muscle and liver from furazolidone-treated pigs was carried out using HPLC, resulting in a similar correlation in swine muscle (r=0.99) and in swine liver (r=0.98). The results suggest that this ELISA is a specific, accurate, and sensitive method of detecting AOZ residues in animal edible tissues.

Determination of nitrofuran residues in milk of dairy cows using liquid chromatography-tandem mass spectrometry

An analytical method has been developed for the determination of total bound and extractable residues of the nitrofuran drugs furazolidone, nitrofurazone, furaltadone, and nitrofurantoin in milk of dairy cows. The method involves overnight acid hydrolysis and simultaneous derivatization of the released side chains with 2-nitrobenzaldehyde. During hydrolysis, the bound metabolites are hydrolyzed to the side chains. After pH adjustment and solid-phase extraction cleanup, the derivatives are detected and quantitated using a liquid chromatography-tandem mass spectrometry system with an atmospheric pressure chemical ionization interface. Validation of the method is accomplished by fortifying control milk with a mixture of side chains at 1, 2, and 4 ng/g. Internal standards are added at the beginning of the procedure to compensate for matrix effects and recovery losses. Method accuracies range from 83 to 104% with coefficients of variation less than 13% for all four analytes. The limits of detection are<or=0.2 ng/g for the side chains. In the milk of a dosed cow, nitrofurantoin exhibits the lowest level of residues among the four nitrofurans. Seventy-two hours after dosing, side-chain residue levels in milk drop below 0.2 ng/g.

Advantages of LC–MS–MS compared to LC–MS for the determination of nitrofuran residues in honey

In the framework of developing analyses for exogenous contaminants in food matrices such as honey, we have compared data obtained by high-performance liquid chromatography coupled with mass spectrometry (LC-MS) to those provided by high-performance liquid chromatography and tandem mass spectrometry (LC-MS-MS). Initial results obtained with LC-MS showed that the technique lacked selectivity, which is why the method was validated by LC-MS-MS. This method involves a solid-phase extraction (SPE) of nitrofuran metabolites and nitrofuran parent drugs, a derivatization by 2-nitrobenzaldehyde for 17 h, and finally a clean-up by SPE. The data obtained show that the limits of detection varied between 0.2 and 0.6 microg kg(-1) for the metabolites and between 1 and 2 microg kg(-1) for nitrofuran parent drugs. The method was applied to different flower honeys. The results showed that nitrofurans (used as antibiotics) are consistently present in this matrix, the predominant compound being furazolidone. Figure Working bees.

Determination of isoflavones in soybean food and human urine using liquid chromatography with electrochemical detection

A highly sensitive high-performance liquid chromatographic method with electrochemical detection (HPLC-ED) was developed for the determination of isoflavones. Electrochemical behaviour of daidzein and genistein was studied on carbon paste electrode (CPE) by adsorptive transfer stripping square wave voltammetry. The obtained electrochemical results were used for the development of HPLC-ED method. Furthermore, isoflavones were separated on an Atlantis dC18 column using a mobile phase consisting of acetonitrile (solvent A) and 0.15M acetate buffer of pH 5.5 (solvent B) at a flow rate 0.4 mL/min. A linear gradient profile (solvent B) was at 0-2 min 87%; 22 min 60%; 27 min 50%; 31 min 45%; 47 min 87%. Full scan of multi-channel coulometric detection was tested and optimal potential at 450 mV was chosen for our purposes. Calibration curves were linear (daidzein R(2) = 0.9993 and genistein R(2) = 0.9987). The detection limit for daidzein/genistein was 480/394 pg/mL (1.8/1.5 nM) and per column 2.4/1.9 pg. Isoflavones extracted from soybean products (farina, meat, milk) by the accelerated solvent extraction (ASE) procedure and isoflavones present in human urine were determined by the HPLC-ED method.

Resolution of ternary mixtures of nitrofurantoin, furaltadone and furazolidone by partial least-square analysis to the spectrophotometric signals after photo-decomposition

An UV spectroscopic method is proposed to analyze mixtures of the nitrofuran derivatives, nitrofurantoin, furaltadone and furazolidone, used in veterinary. The change of absorption spectra due to photo-decomposition is used. A 20% dimethylformamide/water, basic medium of pH 9.4 (ammonium chloride/ammonia) and a time of irradiation of 15 s are selected. Calibration graphs are established, with the percentage of decrease of absorbance as analytical signal, in the range 2-10 microg ml(-1). To analyze mixtures of the three compounds the partial least-squares (PLS) multivariate analysis method is used with the spectra obtained by subtracting the spectra after irradiation to the original spectra. Good results have been obtained in the analysis of synthetic samples and a formulation containing all these compounds.

AAS and AES determination of furaltadone, methadone and trazodone in pharmaceutical formulations

Ion-associate complexes of furaltadone, methadone and trazodone hydrochlorides with [Cd(SCN)(4)](2-) and [Zn(SCN)(4)](2-) were precipitated and the excess unreacted cadmium or zinc complex was determined. A new method using atomic emission and atomic absorption spectrometry for the determination of the above drugs in pure solutions and in pharmaceutical preparations is given. The drugs can be determined by the affort method in the ranges 7.2-72.16, 6.9-69.18 and 8.1-81.6 microg/ml solutions of the three drugs, respectively.

Pharmacological, therapeutic and toxicological properties of furazolidone: some recent research

Some of the recent publications on the pharmacological, therapeutic and toxicological properties of the antimicrobial agent furazolidone (FZ) are briefly reviewed. In animals, most of the recently published papers focus on (1) the methodology of measuring the residues of the drug and its metabolites in edible tissues; (2) the carcinogenicity and genotoxicity of FZ; (3) the cellular and molecular basis of FZ-induced cardiomyopthy, and the action of different cardioprotectant drugs thereon; and (4) hormonal effects. In humans, the use of FZ as an anti-ulcer drug and in controlling infectious diseases, especially opportunistic infections in AIDS patients, is described.