Norfloxacin Residues Research Articles

Norfloxacin affects inorganic nitrogen compound transformation in tailwater containing Corbicula fluminea

The Asian clam, Corbicula fluminea, commonly used in engineered wetlands receiving tailwater, affects nitrogen compound transformation in water. This study investigates how a commonly observed antibiotic in tailwater, norfloxacin, impact nitrogen compound transformation in tailwater containing C. fluminea. The clam was exposed to artificial tailwater with norfloxacin (0, 0.2, 20, and 2000 μg/L) for 15 days. Water properties, C. fluminea ecotoxicity responses, microorganism composition and nitrification- or denitrification-related enzyme activities were measured. Results revealed norfloxacin-induced increases and reductions in tailwater NH4+ and NO2− concentrations, respectively, along with antioxidant system inhibition, organ histopathological damage and disruption of water filtering and digestion system. Microorganism composition, especially biodiversity indices, varied with medium (clam organs and exposure water) and norfloxacin concentrations. Norfloxacin reduced NO2− content by lowering the ratio between microbial nitrifying enzyme (decreased hydroxylamine oxidoreductase and nitrite oxidoreductase activity) and denitrifying enzyme (increased nitrate reductase and nitrite reductase activity) in tailwater. Elevated NH4+ content resulted from upregulated ammonification and inhibited nitrification of microorganisms in tailwater, as well as increased ammonia emission from C. fluminea due to organ damage and metabolic disruption of the digestion system. Overall, this study offers insights into using benthic organisms to treat tailwater with antibiotic residues, especially regarding nitrogen treatment.

Development of two new matrix certified reference materials for enrofloxacin and norfloxacin residues in fish meat powder

In this study, two matrix certified reference materials (CRMs) for accurate measurement of enrofloxacin and norfloxacin in fish meat powder were produced, respectively (GBW10167, GBW10168). Raw material was obtained by feeding fish with positive drugs. The homogeneity, stability and certification of two matrix CRMswere stµdied by using a liquid chromatography tandem mass spectrometric with isotope-labeled internal standard method. The certified value of enrofloxacin in fish meat powder was 62.5 µg/kg with an expanded uncertainty of 6.3 µg/kg (coverage factor k = 2, at 95% confidence range). The certified value of norfloxacin in fish meat powder was 41.8 µg/kg with an expanded uncertainty of 5.9 µg/kg (coverage factor k = 2, at 95% confidence range). In addition, homogeneity, long-term stability at −20 °C for a year, and short-term stability at 4 °C, 25 °C, and 50 °C for nine days was assessed in detail. The results showed that the samples were stable under the above conditions.

Construction of a Molecularly Imprinted Sensor Modified with Tea Branch Biochar and Its Rapid Detection of Norfloxacin Residues in Animal-Derived Foods.

Norfloxacin (NOR) is a common antibiotic used in humans and animals, and its high levels can cause intolerance or poisoning. Therefore, NOR levels in animal-derived foods must be monitored due to potential side effects and illegal use phenomena. This research centered on the development of an environmentally friendly electrochemical sensor for NOR detection. Potassium carbonate activated tea branch biochar (K-TBC) as an efficient use of waste was coated on the surface of glassy carbon electrode (GCE), and a molecular-imprinted polymer (MIP) layer was subsequently electropolymerized onto the modified electrode. NOR was used as template molecule and o-phenylenediamine (o-PD) and o-aminophenol (o-AP) were used as bifunctional monomers. The electrochemical sensor was built and its electrochemical behavior on NOR was investigated. The sensor demonstrated an excellent linear current response to NOR concentrations in the ranges of 0.1-0.5 nM and 0.5-100 nM under ideal experimental circumstances, with a detection limit of 0.028 nM (S/N = 3). With recoveries ranging from 85.90% to 101.71%, the designed sensor was effectively used to detect NOR in actual samples of milk, honey, and pork. Besides, the fabricated sensor had low price, short detection time, good selectivity and stability, which can provide a theoretical and practical basis for the actual monitoring of NOR residues.

Colorimetric Chemosensor Based on Fe3O4 Magnetic Molecularly Imprinted Nanoparticles for Highly Selective and Sensitive Detection of Norfloxacin in Milk.

Long-term use of norfloxacin (NOR) will cause NOR residues in foods and harm human bodies. The determination of NOR residues is important for guaranteeing food safety. In this study, a simple, selective, and label-free colorimetric chemosensor for in situ NOR detection was developed based on Fe3O4 magnetic molecularly imprinted nanoparticles (Fe3O4 MMIP NPs). The Fe3O4 MMIP NPs showed good peroxidase-like catalytic activity to 3,3',5,5'-tetramethylbenzidine (TMB) and selective adsorption ability to NOR. The colorimetric chemosensor was constructed based on the Fe3O4 MMIP NPs-H2O2-TMB reaction system. The absorbance differences were proportional to the concentrations of NOR in the range of 10-300 ng/mL with a limit of detection at 9 ng/mL. The colorimetric chemosensor was successfully applied to detect NOR residue in milk. The recovery range was 78.2-95.81%, with a relative standard deviation of 2.1-9.88%. Together, the proposed colorimetric chemosensor provides a reliable strategy for the detection of NOR residues in foods.

A highly sensitive and dual-readout immunoassay for norfloxacin in milk based on QDs-FM@ALP-SA and click chemistry

A dual-readout immunoassay based on QDs-FM@ALP-SA and click chemistry was developed for quick and sensitive detection of norfloxacin (NOR), which is an important fluoroquinolone antibiotic. In the system, the NOR-biotin conjugate (NOR-Biotin) was synthesized by click chemistry for signal transformation, and alkaline phosphatase–labeled streptavidin (ALP-SA) was attached to quantum dot fluorescence microspheres (QDs-FM) by an activated ester method to form QDs-FM@ALP-SA for signal amplification. Here, QDs-FM was a dual-functional carrier: it was used not only as a chemiluminescence signal amplification carrier but also as a fluorescent signal due to its fluorescence character. The NOR antibody was coated on a 96-well chemiluminescence microtiter plate, and NOR-Biotin was bound to the antibody specifically. Then, QDs-FM@ALP-SA was combined with NOR-Biotin to develop a direct competition chemiluminescence/fluorescence immunoassay (dc-CLIA/FIA). The IC50 values were 0.345 and 1.206 ng/mL for dc-CLIA/FIA, respectively. The linear range was 0.013–12.48 ng/mL and 0.042–39.86 ng/mL, respectively. The recovery from the standard fortified blank milk samples was in the range of 86.44%–101.3%. Therefore, this method could be a useful tool for routine screening of NOR residues in milk.

A magnetic phosphorescence molecularly imprinted polymers probe based on manganese-doped ZnS quantum dots for rapid detection of trace norfloxacin residual in food

This paper reports the development of a novel probe based on magnetic room-temperature phosphorescence quantum dots with molecularly imprinted polymers (MQD-MIPs) for the rapid detection of trace norfloxacin (NFX) residual in complex food matrix. The highly selective probe was constructed by surface molecular imprinting technology using magnetic materials (Fe3O4 nanoparticles) as core, Mn-doped ZnS quantum dots (Mn-ZnS QDs) as phosphorescent materials, NFX as template, 3-aminopropyltriethoxysilane as functional monomer, and tetraethoxysilane as crosslinking agent. The as-obtained MQD-MIPs were characterized in detail by transmission electron microscopy, scanning electron microscopy, X-ray powder diffraction, Fourier transform infrared spectrometry, and vibrating sample magnetometer. A magnetic strength of 37.64 emu g−1 was recorded. Also, the probe displayed excellent room temperature phosphorescence properties with excitation/emission peaks at 300/590 nm. Under the optimized conditions, the detection time was less than 40 min, phosphorescence intensity varied linearly with concentration from 1 to 90 μg·L−1, and detection limit reached as low as 0.80 μg·L−1. Furthermore, the MQD-MIPs-based probe successfully detected norfloxacin residues in spiked fish and milk samples with recoveries of 90.92–111.53% and RSD <7%, outperforming the standard control method-HPLC-FLD (recoveries of 85.89–118.28%).

P-Cu2O/n-ZnO heterojunction thin films with enhanced photoelectrochemical properties and photocatalytic activities for norfloxacin

A two-step electrochemical deposition technique was applied to fabricate p-Cu2O/n-ZnO heterojunction thin films. The influence of the deposition potential upon photoelectric performance of the prepared samples was examined utilizing XRD, XPS, SEM, UV–Vis, and electrochemical tests. The results show that the deposition potential has a substantial influence on the properties of the prepared samples. When the deposition potential is −0.45 V, the peak intensity of the (111) crystal plane of the prepared heterojunction is the highest, the band gap increased, and the morphology changes obviously compared to those of Cu2O. The transient photocurrent value is three times that of pure Cu2O, and the charge transfer resistance significantly reduced. The p-Cu2O/n-ZnO heterojunction has a high carrier concentration. Photocatalytic degradation experiments show that degradation rate of norfloxacin increases by 14.4%–76.6%. The enhanced photocatalytic performance of Cu2O is mainly due to the formation of a high-quality heterojunction and the change in the energy band structure, which promotes the transfer rate of the carrier and the separation of photogenic electron hole pairs, thus effectively improving the catalytic efficiency of photocatalysts. Active species detection experiments reveal that positive hole and superoxide anion radical play leading roles in norfloxacin molecule decomposition. In addition, a possible mechanism for the photocatalytic performance of p-Cu2O enhanced by n-ZnO is proposed according to the analysis of the bandgap of p-Cu2O and n-ZnO, along with the built-in electric field formed in the p-n heterojunction. This study provides an effective and alternative method for removing norfloxacin residues in wastewater.

Detection of Norfloxacin in Muscle, Liver and Kidney of Broiler Chicken

The present study was undertaken to determine the residues of norfloxacin in muscle, liver and kidney of broiler chicken. On the basis of surveillance study, commonly used antibiotic norfloxacin was selected for quantifying the concentration in broiler chicken meat samples. The HPLC system was equipped with photodiode array and C18 hypersil column. The mobile phase consisting of 1 ml Ortho phosphoric acid (85 per cent v/v), 100 ml water HPLC grade with acitonitrile HPLC grade, 87:12 (v/v) then pH was adjusted to 2.0 with triethylamine HPLC Grade. The results indicated that out of 180 samples analysed, 3 liver samples of target stations, viz. T3, T6 and T10 were found positive for norfloxacin residues with concentrations of 2.00, 2.60 and 2.31 µg/kg, respectively. Samples collected from other target stations did not show residual concentration of norfloxacin in muscle, liver and kidney samples.

Residual and migration characteristics of norfloxacin in two mangrove ecosystems

Direct discharge of aquaculture wastewater in coastal areas could increase concentrations of antibiotics in coastal mangrove forests. This study focused on the Gaoqiao Mangrove Nature Reserve in Zhanjiang City, Guangdong Province. Norfloxacin (NOR) residues in rhizosphere sediments, plant roots, branches, and leaves of two dominant mangrove communities, Rhizophora stylosa and Avicennia marina, the correlation between physical properties of rhizosphere deposition and residual NOR in sediments, and NOR accumulation in the root system were analyzed. Significant differences were noted in NOR residues in rhizosphere sediments of R. stylosa and A. marina, with higher NOR concentrations than those in other wetland sediments locally and abroad. NOR accumulation in R. stylosa was higher in the branches than in the roots and was also significantly higher than that in A. marina. Thus, both species could accumulate NOR from the environment with R. stylosa showing a stronger potential to purify the environment. Cation exchange capacity and total organic carbon could affect NOR distribution in the rhizosphere sediment, and total organic carbon content could reduce NOR uptake by mangrove roots. This study contributes to research on the migration and adsorption characteristics of antibiotics in mangrove wetlands.

Detection of antibiotic residues in pork using paper-based microfluidic device coupled with filtration and concentration

This work demonstrates a sensitive and rapid method for the detection of antibiotic residues in food samples by employing the filtration behaviour of paper combined with aggregation and precipitation of chemical reagents. Using this concept, we successfully determined the presence of oxytetracycline and norfloxacin residues in pork using metal complexation on microfluidic paper-based analytical devices (μPADs). The base substrate (top layer of the device) was fabricated by printing letter channels of the words “oxytetracycline” and “norfloxacin” before functionalization with copper (II) sulfate pentahydrate in 0.5 M sodium hydroxide and iron (III) nitrate nanohydrate in 5 mM ammonia solution for the detection of oxytetracycline and norfloxacin separately. A transition metal hydroxide formed upon reaction that created solid precipitates on paper and allowed antibiotic residues to bind to the metal ions via coordination chemistry. The metal ion-antibiotic complex could form on the filter paper and generated a visible color change with the detection limit of 1 ppm for both oxytetracycline and norfloxacin in pork. This procedure of filtration and concentration in combination with a simple text-reporting approach allows the end users to achieve a low limit of detection as well as easy result interpretation in food safety monitoring.

Preliminary study on qualitative and quantitative detection of norfloxacin based on terahertz spectroscopy

Norfloxacin is a kind of quinolone bactericide which is widely used in food industry, livestock feed and medicine area. At present, how to develop a rapid, convenient and accurate technique for qualitative and quantitative detection of norfloxacin is still a challenge. In this study, Terahertz Time-domain Spectroscopy technology (THz-TDS) was used to explore qualitative and quantitative analysis of norfloxacin. Forty-five norfloxacin samples with different levels were prepared. The pure norfloxacin powder was mixed with polyethylene (PE) powder together and made into tablets by tablet-making machine. The minimum detection concentration was 10% and the maximum detection concentration evaluated in the paper was 90%. Then, terahertz (THz) spectra of each sample were measured on K15 THz-TDS equipment. The multiple linear regressions and the partial least squares regression algorithms were used to establish a model to make quantitative analysis. From the results, two typical fingerprint peaks of norfloxacin in terahertz band were observed at 0.944 THz and 1.206 THz, and the correlation coefficient and the root mean square error of the established model reached 0.9908 and 0.0481, respectively, which showed that the model performed well for the prediction. This preliminary study indicates that THz spectroscopy has great potential for future screening applications to detect the presence of norfloxacin residues in food, livestock feed and medicine industries. Keywords: Terahertz spectroscopy, norfloxacin, qualitative and quantitative detection, model, correlation coefficient DOI: 10.25165/j.ijabe.20171005.2962 Citation: Long Y, Li B. Preliminary study on qualitative and quantitative detection of norfloxacin based on terahertz spectroscopy. Int J Agric & Biol Eng, 2017; 10(5): 262–268.

Preliminary study on qualitative and quantitative detection of norfloxacin based on terahertz spectroscopy

Norfloxacin is a kind of quinolone bactericide which is widely used in food industry, livestock feed and medicine area. At present, how to develop a rapid, convenient and accurate technique for qualitative and quantitative detection of norfloxacin is still a challenge. In this study, Terahertz Time-domain Spectroscopy technology (THz-TDS) was used to explore qualitative and quantitative analysis of norfloxacin. Forty-five norfloxacin samples with different levels were prepared. The pure norfloxacin powder was mixed with polyethylene (PE) powder together and made into tablets by tablet-making machine. The minimum detection concentration was 10% and the maximum detection concentration evaluated in the paper was 90%. Then, terahertz (THz) spectra of each sample were measured on K15 THz-TDS equipment. The multiple linear regressions and the partial least squares regression algorithms were used to establish a model to make quantitative analysis. From the results, two typical fingerprint peaks of norfloxacin in terahertz band were observed at 0.944 THz and 1.206 THz, and the correlation coefficient and the root mean square error of the established model reached 0.9908 and 0.0481, respectively, which showed that the model performed well for the prediction. This preliminary study indicates that THz spectroscopy has great potential for future screening applications to detect the presence of norfloxacin residues in food, livestock feed and medicine industries. Keywords: Terahertz spectroscopy, norfloxacin, qualitative and quantitative detection, model, correlation coefficient DOI: 10.25165/j.ijabe.20171005.2962 Citation: Long Y, Li B. Preliminary study on qualitative and quantitative detection of norfloxacin based on terahertz spectroscopy. Int J Agric & Biol Eng, 2017; 10(5): 262–268.

Determination of four kinds of illegal additive residues in sprouts and source beans by high performance liquid chromatography-tandem mass spectrometry

A reversed-phase high performance liquid chromatography coupled with tandem mass spectrometric (LC-MS/MS) method was developed for the determination of 4-chlorophenoxyacetic acid, 6-benzylaminopurine, enrofloxacin and norfloxacin residues in sprouts and source beans. The sample was extracted by acetonitrile containing 0.1% acetic acid and concentrated. The chromatographic analysis was carried out on a C18 column with methanol and 0.1% formic acid solution as the mobile phases in gradient elution program. The MS analysis was set in electrospray ionization mode and separated to two segments of positive and negative modes. The precursor ions were m/z 189.9, 226.1, 359.9 and 320.1, while the product ions for quantification were m/z 127.0, 91.2, 315.9 and 276.2 for 4-chlorophenoxyacetic acid, 6-benzylaminopurine, enrofloxacin and norfloxacin, respectively. The calibration curves showed good linearity in the range of 5 - 200 microg/L with correlation coefficients more than 0.995. The limits of detection (LODs) were 1 microg/kg and the limits of quantification (LOQs) were 5 microg/kg for the four compounds spiked in mung bean sprouts and mung beans. The recoveries of the four compounds spiked at three levels of 5.0, 10.0 and 20.0 microg/kg ranged from 70% to 91%, with the relative standard deviations (RSDs) less than 14%. The method established is accurate, sensitive, simple, and has considerable advantages in the analysis of the four kinds of illegal additive residues in sprouts and beans simultaneously.

Portable Surface Plasmon Resonance Immunosensor for the Detection of Fluoroquinolone Antibiotic Residues in Milk

An inexpensive and portable surface plasmon resonance (SPR) sensor, SPReeta Evaluation Kit SPR3, has been used to develop a biosensor for the determination of fluoroquinolone antibiotics (FQs) and to demonstrate its performance analyzing FQ residues in milk samples. The SPReeta three-channel gold chips were activated with a mixed self-assembled monolayer (m-SAM) and functionalized with a FQ haptenized protein. Binding of the antibody produced a concentration-dependent increase of the SPR signal as a result of the change in the refraction index. Similarly, the presence of the FQ produced a dose-dependent decrease of the response, which allowed a good limit of detection (LOD) to be obtained (1.0 ± 0.4 μg L(-1) for enrofloxacin in buffer). The response was reproducible in all three channels, on different injections and days, and also between chips. Milk samples could be analyzed after a simple sample treatment involving fat removal by centrifugation and dilution with water. Under these conditions calibration curves were obtained showing that FQ residues can be analyzed in milk samples with an IC(50) value of 26.4 ± 7.2 μg L(-1) and a LOD of 2.0 ± 0.2 μg L(-1) (for enrofloxacin), far below the European Union regulations for this antibiotic family in this matrix. Finally, the paper also demonstrates that the biosensor is able to selectively detect the presence of FQs in milk samples, even in the presence of other antibiotics. Enrofloxacin, ciprofloxacin, and norfloxacin residues were detected in blind samples supplied by Nestlé Co.

Development and Optimization of an Indirect Competitive ELISA for Detection of Norfloxacin Residue in Chicken Liver

An indirect competitive ELISA has been developed for the determination of Norfloxacin (NFLX) residue in chicken liver. For this reason, carbodiimide active ester method was employed to synthesize the artificial antigen of NFLXBSA, and coating antigen of NFLX-OVA, and rabbits were used to produce the anti-NFLX polyclonal antibody. Based on the square matrix titration, an icELISA method was developed for the quantitative detection of NFLX. The dynamic range was from 0.006 to 38 ng/mL, with LOD and IC50 value of 0.004 ng/mL and 0.48 ng/mL, respectively. Except for a high cross-reactivity to Ciprofloxacin (38%) and Sarafloxacin (33%), negligible cross-reactivity to the other compounds was observed. After optimization, 10-fold dilution in chicken liver extract gave an inhibition curve almost the same as that in PBS buffer. When spiked in liver extract at 8, 20, and 50 ng/mL, the recovery rate was 90- 117.8% for intra-assay, and 97.5-114.4% for inter-assay, respectively. The relative standard deviation ranged from 5.6-9.2% for intra-assay and 5.9-11% for inter-assay. Therefore, the developed icELISA method could be used for the routing screening of NFLX residues in chicken edible tissues.

Production and Characterization of Monoclonal Antibodies against Norfloxacin

To monitor the abuse of Norfloxacin (NFLX), developing a monoclonal antibody (mAb) based enzyme linked immunosorbent assay (ELISA) kit is our future goal. For this purpose, Hybridomas were prepared by fusing NS0 mouse myeloma cells with splenocytes isolated from immunized BALB/c mouse. Noncompetitive and competitive indirect ELISA was employed to screen positive cell clones. Caprylic acid ammonium sulphate (CAAP) method was used to purify NFLX mAb and the Batty saturation method was used to determine the affinity constant (Ka). Finally, six hybridoma cell lines named N1-A2, N2-B3, N2-B5, N3-C6, N4-D5, and N4-D8 were screen out, their corresponding mAbs were of the IgG1 isotype with k light chain, and the Kas of all mAbs were between 3.2×109 and 2.6×1010 L/mol. Based on the square matrix titration, two representative icELISA curves were established. The dynamic range for N3-C6 in assay buffer was from 0.003 to 38 ng/mL, with LOD and IC50 value of 0.002 ng/mL and 0.16 ng/mL, respectively. As to N2-B5, it was from 0.004 to 26 ng/mL, with LOD and IC50 value of 0.002 and 0.22 ng/mL, respectively. Except for a high cross-reactivity (CR) to Pefloxacin (33.6%) and Lomefloxacin (21.8%), this mAb originated from N3-C6 exhibited negligible CR values to other chemicals. Therefore, the established hybridomas put a potential for the development of a rapid test kit and provide an alternative method for the detection of NFLX residues in food producing animals.

Quantitative determination of norfloxacin residues and effect of biol and freezing in chicken tissues

Quantitative determination of norfloxacin residues and effect of biol and freezing in chicken tissues

High-performance thin-layer chromatography method for monitoring norfloxacin residues on pharmaceutical equipment surfaces

This paper presents a high-performance thin-layer chromatography (HPTLC) method with direct fluorescence measurement for the determination of norfloxacin. The method was validated for the monitoring of norfloxacin residues on stainless steel surfaces at the allowed limit of 10 mg of norfloxacin per square meter. However, it can be adapted for lower amounts of residues owing to the low detection limit of norfloxacin (about 5 ng) and can also be used for other surface materials. Test solutions were analyzed by the new HPTLC method and the known HPLC method for comparison. Accuracy and precision of the new HPTLC method, with a subsequent quantification by densitometer or video system, are comparable with those of the HPLC method.