Determination Of Chloramphenicol In Milk Research Articles

Tuning the shell thickness of N-doped interconnected hollow carbon sphere for the electrochemical sensing of antibiotic drug chloramphenicol.

N-doped hollow carbon spheres (NHCSs) with different shell thicknesses are constructed using various amounts of SiO2 precursor. An interconnected framework with diminished wall thickness ensures an efficient and continuous electron transport which helps to enhance theperformance of NHCS. Improvement of the electrocatalytic performance was shown in the determination of antibiotic drug chloramphenicol (CAP) due to theunique hollow thin shell morphology, ample defect sites, accessible surface area, higher surface-to-volume ratio and ansynergistic effect. Boosted electrocatalytic activity of 1.5 N-doped HCS (1.5 NHCS) was applied to detect CAP with a linear range and detection limit of 1-1150µM and 0.098µM (n = 3), respectively, with superior storage stability and considerable sensitivity. These results suggest that the proposed work can besuccessfully applied to the determination of CAP in milk and water samples.

Flake-like structure of SrTiO3 nanoparticles dispersed on graphene oxide: A selective and sensitive electrochemical sensor for determination of chloramphenicol in milk and honey samples

The use of Chloramphenicol (CAP), a potent antibiotic with broad-spectrum capabilities in food-producing animals has been restricted by the European Union and several other countries due to its severe side effects. Thus, CAP must be detected quickly and sensitively. In this investigation, the preparation of SrTiO3 nanoparticles was carried out utilizing a hydrothermal technique. The as-synthesized strontium titanate was decorated on the graphene oxide (SrTiO3/GO) using an ultrasonication method. An electrochemical sensor was developed by employing a modified electrode consisting of SrTiO3/GO, which can accurately detect CAP in food samples. The synergistic effect of SrTiO3 and GO could improve the peak current response. Remarkably, the SrTiO3/GO-modified glassy carbon electrode has a LOD and sensitivity of 6.08 µM nM and 2.771 µA·μM−1·cm−2, respectively. This modified electrode was evaluated in food samples and had an outstanding reaction with a high percentage of recovery, which makes it a potential electrocatalyst for CAP detection.

A graphene-oxide-based aptasensor for fluorometric determination of chloramphenicol in milk and honey samples utilizing exonuclease III-assisted target recycling and Nb.BbvCI-powered DNA walker cascade amplification

Herein, a graphene oxide (GO)-based fluorescence aptasensor was developed for the sensitive and selective detection of chloramphenicol (CAP), based on exonuclease III (Exo III)-assisted target recycling and Nb.BbvCI-driven DNA walker cascade amplification. Interactions between CAP, hairpin1(HP1), hairpin2 (HP2), and 3′-amino modified hairpin3 (HP3) labeled with carboxyfluorescein (FAM) and covalently coupled to GO enabled efficient CAP detection. CAP was quantitatively assayed by measuring fluorescence at excitation/emission wavelengths of 480/514 nm, resulting from the accumulation of released FAM. A good linear range of 1 fM to 1 nM and a limit of detection (LOD) of 0.875 fM (signal-to-noise (S/N)= 3) were achieved. This aptasensor can distinguish the CAP from interference antibiotics with good specificity and selectivity, even if the concentration of the interfering substance is ten-fold higher than the target concentration. Moreover, the developed fluorescence aptasensor was successfully applied for the detection of CAP in spiked milk and honey samples. Thus, this method is potentially applicable for assaying CAP in foods and provides a promising strategy for the development of fluorescence aptasensors for environmental sample analysis.

Magnetic nanofluid based on green deep eutectic solvent for enrichment and determination of chloramphenicol in milk and chicken samples by high-performance liquid chromatography-ultraviolet: Optimization of microextraction

In this work, magnetic nanofluid based on a deep eutectic solvent that constricts through a simple and easy route, and subsequently applied for the preconcentration and microextraction of chloramphenicol (CAP) as a hazardous drug from milk and chicken samples via syringe-to-syringe microextraction prior to its determination by high-performance liquid chromatography–ultraviolet (HPLC-UV). In addition, the optimum conditions of effective factors were searched by the central composite design (CCD), and subsequently, at their optimum value, the figures of merit were evaluated. Also, the suggested method illustrated a low limit of detection (0.2 ng mL−1), a low limit of quantitation (0.67 ng mL−1), and a good linear range with an R2 of 0.996. The CAP relative recoveries in milk and chicken samples were 90.3%–95.1%, with relative standard deviations lower than 4.2%. The current enhancement technique is simple, easy, and rapid, which makes it suitable for quantification of CAP by HPLC-UV at trace levels in complicated materials with reliable and reproducible results.

Molecularly imprinted electrochemical sensor based on multi-walled carbon nanotubes for specific recognition and determination of chloramphenicol in milk

A molecularly imprinted electrochemical sensor of chloramphenicol (CAP) with high sensitivity and good selectivity is introduced in this paper. Glassy carbon electrode (GCE) was modified by chitosan-multiwalled carbon nanotubes (CS-MWCNTs), the CS could improve the dispersion of MWCNTS, and the MWCNTS could significantly improve the current response of the sensor, thus improving the sensitivity. CAP was used as a template molecule and o-phenylenediamine (o-PD) was used as a functional monomer, respectively. Molecularly imprinted polymers (MIPs) were prepared on the surface of a GCE modified with CS-MWCNTs by electro-polymerization. The MIPs provided specific recognition sites for the detection of chloramphenicol. The experimental parameters such as polymerization cycle, concentration ratio of template molecule to functional monomer, supporting electrolyte pH and incubation time were optimized. Under optimized experimental conditions, the sensor has a linear range of 0.1–1000 ng/mL and the limit of detection (LOD) of 3.3 × 10−2 ng/mL (S/N = 3). The sensor had high selectivity, good stability and reproducibility for the detection of CAP, and it has been successfully used for the determination of CAP in real spiked milk samples.

Synthesis of rGO@PDA@AuNPs for an effective electrochemical chloramphenicol sensor

An efficient electrochemical sensor for the detection of chloramphenicol was prepared by using rGO@PDA@AuNPs composite. The electrochemical properties of rGO@PDA@AuNPs were evaluated by cyclic voltammetry and differential pulse voltammetry methods. Under the best conditions, the detection range of rGO@PDA@AuNPs was wide (0.1–100 μM), and the detection limit was low (0.058 μM), with excellent selectivity, stability and reproducibility. In addition, an electrochemical sensor based on rGO@PDA@AuNPs can be used for the determination of chloramphenicol in milk with good results.

Application of molecularly imprinted polymers and dual-emission carbon dots hybrid for ratiometric determination of chloramphenicol in milk

Chloramphenicol (CLP) is a veterinary antibiotic that has been banned due to its severe side effects but it is still illegally used in animal husbandry. In this work, the fabrication of simple, fast-response and highly selective ratiometric probe for sensitive visual detection of CLP antibiotic at trace levels in both indoor and outdoor is reported. For the construction of the ratiometric fluorescence probe (mMIP@YBCDs), two kinds of different carbon dots with yellow emission (Y/CDs, 560 nm) and blue emission carbon dots (B/CDs, 440 nm) were used as target sensitive and as reference dyes respectively. Besides, molecularly imprinted mesoporous silica was used as a recognized part of the probe. Upon the addition of different concentrations of CLP, the fluorescence of Y/CDs was quenched significantly while the fluorescence intensity of B/CDs stayed constant which was accompanied by gradual fluorescence color change from yellow-to-blue. The ratiometric probe has a linear response in the range of 0.1–3 μgL−1 with a detection limit 0.035 μgL−1. The practicality of the ratiometric method was validated by the quantification of CLP in milk samples.

Improved conductivity of flower-like MnWO4 on defect engineered graphitic carbon nitride as an efficient electrocatalyst for ultrasensitive sensing of chloramphenicol

Environmental hazards caused by chloramphenicol has attained special attention. Fast, accurate and reliable detection of chloramphenicol in foodstuffs and water samples is of utmost importance. Herein, we developed a g-C3N4/MnWO4 composite for the selective and sensitive detection of chloramphenicol. Successful fabrication of g-C3N4/MnWO4 composite was verified by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), x-ray diffraction (XRD) and x-ray photo electron spectroscopy (XPS) techniques. Electrochemical characteristics were evaluated by using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). The g-C3N4/MnWO4 modified glassy carbon electrode has shown the highest electrocatalytic activity towards chloramphenicol with a decreased reduction potential of -0.547 V and increased cathodic peak current. The developed sensor has shown excellent performance for the detection of chloramphenicol with a sensitivity of 0.9986 μA nM−1 cm−2 and LOD of 1.03 nM in a broad linear range of 4.0–71 nM. In addition, the fabricated sensor has achieved anti-interference ability, good stability, excellent repeatability and remarkable reproducibility for the detection of chloramphenicol. The fabricated sensor applied for the determination of chloramphenicol in milk, human blood serum and sewage samples, in which significant and satisfactory results were achieved.

Tunable Synthesis of CoP and CoP2 Decorated 3D Carbon Nanohybrids and the Application of CoP2 Decorated One in Electrochemical Detection of Chloramphenicol in Milk and Honey

Cobalt phosphides embedded in electrocatalysts with low Co/P ratio have recently garnered a great deal of attention due to their high catalytic activities. However, compared to the studies on Co2P and CoP based catalysts, the studies on facile and controllable synthesis of CoP2 based catalysts are few. Herein, two types of cobalt phosphides embedded in 3D carbon nanohybrids (CoPx-N-C) with controllable Co/P ratio were developed via a facile one-step phosphidation-carbonization using a cobalt centered metal-organic framework, ZIF-67, as building block. Based on the high affinity between chloramphenicol (CAP) and cobalt phosphide, the as-prepared CoPx-N-C hybrids were further utilized as electrode components in electrocatalytic determination of CAP in milk and honey. The abundant cobalt phosphide component exhibits high affinity to CAP thus favors its adsorption and facilitates the followed redox reaction. The P-rich CoP2-N-C shows better performance than the metal-rich CoP-N-C in CAP detection, owing to its better electro-activity. The developed CoP2-N-C based sensor exhibits good analytical performance with low detection limit of 0.044 μM (signal-to-noise ratio, S/N = 3) and wide linear range (0.2∼40 μM and 40∼200 μM). The proposed sensor was also applied in the analyses of spiked milk and honey samples, demonstrating its feasibility in CAP analysis.

Packed-nanofiber solid phase extraction coupled with HPLC for the determination of chloramphenicol in milk

A sensitive analytical method based on packed-nanofiber solid phase extraction (PFSPE) and high performance liquid chromatography (HPLC) has been developed for determining chloramphenicol (CAP) in milk.

Green synthesized gold nanoparticles decorated graphene oxide for sensitive determination of chloramphenicol in milk, powdered milk, honey and eye drops

A simple and rapid green synthesis using Bischofia javanica Blume leaves as reducing agent was developed for the preparation of gold nanoparticles (AuNPs). AuNPs decorated graphene oxide (AuNPs/GO) was prepared and employed for the sensitive amperometric determination of chloramphenicol. The green biosynthesis requires less than 40s to reduce gold salts to AuNPs. The formations of AuNPs and AuNPs/GO were evaluated by scanning electron and atomic force microscopies, UV–Visible and energy dispersive X-ray spectroscopies, X-ray diffraction studies, and electrochemical methods. AuNPs/GO composite film modified electrode was fabricated and shown excellent electrocatalytic ability towards chloramphenicol. Under optimal conditions, the amperometric sensing platform has delivered wide linear range of 1.5–2.95μM, low detection limit of 0.25μM and high sensitivity of 3.81μAμM−1cm−2. The developed sensor exhibited good repeatability and reproducibility, anti-interference ability and long-term storage stability. Practical feasibility of the sensor has been demonstrated in food samples (milk, powdered milk and honey) and pharmaceutical sample (eye drops). The green synthesized AuNPs/GO composite has great potential for analysis of food samples in food safety measures.

Electrochemical determination of chloramphenicol in milk and honey using vertically ordered silica mesochannels and surfactant micelles as the extraction and anti-fouling element

Chloramphenicol (CAP), an antibiotic, is closely related to the food safety, ecological environment and human health. It is therefore of great importance to develop simple and rapid methods for CAP determination. We report in this work the utilization of indium tin oxide (ITO) electrodes modified with a binary assembly of vertical silica mesochannels (VSMs) and cylindrical surfactant micelles (CSMs) for the electrochemical detection of CAP. Each hard VSM of 2–3nm in diameter supports and confines a soft CSM of cetyltrimethylammonium bromide (CTAB), which has a hydrocarbon core capable of extracting and concentrating lipophilic organic analytes from sample solutions. So the CSM@VSM modified electrode exhibited an analytical performance for CAP apparently superior to bare and VSM modified electrodes. Under optimized conditions, two linear dynamic concentration ranges were obtained for CAP determination using differential pulse voltammetry, namely 0.1 to 3.6ppm and 3.6 to 15.0ppm, as well as a low limit of detection at 40ppb. Moreover, thanks to the ultrasmall size of silica channels and the lipophilic microenvironment of micelle cores, the CSM@VSM film displayed an excellent hydrophobic selectivity and anti-fouling ability by preventing unwanted substances from accessing to and contaminating the underlying electrode surface. Therefore, reliable results were obtained for direct electrochemical determination of CAP in real samples, such as milk and honey, without pre-treatment.

Determination of chloramphenicol in milk by ten chemiluminescent immunoassays: influence of assay format applied

Development of 10 chemiluminescent immunoassays for the detection of CAP for a comparison study. First systematic assessment in sensitivity and robustness of different immunoassay formats based on diverse combinations of coating, reverse reaction and antibody source.

The validation of a new high throughput method for determination of chloramphenicol in milk using liquid–liquid extraction with low temperature partitioning (LLE-LTP) and isotope-dilution liquid chromatography tandem mass spectrometry (ID-LC-MS/MS)

The first application of LLE-PBT for determination of chloramphenicol in milk.

Determination of Chloramphenicol in Milk Using a QuEChERS-Based on Liquid Chromatography Tandem Mass Spectrometry Method

A quantitative method for the determination of chloramphenicol in milk samples was developed based on the QuEChERS (quick, easy, cheap, effective, rugged, and safe) approach for liquid chromatography–tandem mass spectrometry (LC–MS/MS). Homogenized milk samples were extracted with acetonitrile. The partitioning step was performed after the addition of magnesium sulfate and sodium chloride. Chloramphenicol was determined using the electrospray negative ionization mode with tandem mass spectrometry. The procedure was validated according to the requirements of Commission Decision 2002/657/EC. The apparent recovery ranged from 90% to 110% and within-laboratory reproducibility was lower than 12%. The calculated limit of decision was 0.10 μg kg−1 and the detection capability was 0.15 μg kg−1. Validation results demonstrated that this method fulfills criteria for the determination of chloramphenicol in milk.

Development of a highly sensitive chemiluminescence enzyme immunoassay using enhanced luminol as substrate

In this study, a high sensitivity chemiluminescence enzyme immunoassay (CLEIA) based on novel enhancers was developed. Under optimal conditions, we developed an enhanced chemiluminescence reaction (ECR) catalyzed by horseradish peroxidase (HRP-C) in the presence of 3-(10'-phenothiazinyl) propane-1-sulfonate (SPTZ) and 4-morpholinopyridine (MORP) as enhancers. The limit of detection of the newly prepared chemiluminescent cocktail for HRP was 0.33 pg/well, which is lower than that of commercial Super Signal substrate. The results showed that this novel chemiluminescent cocktail can significantly increase the light output of HRP-catalyzed ECR, which can be translated into a corresponding improvement in sensitivity. Similar improvements were observed in CLEIA for the determination of chloramphenicol in milk. In addition, the ECR of N-azoles as secondary enhancer was also presented.

An ultrasensitive chemiluminescent ELISA for determination of chloramphenicol in milk, milk powder, honey, eggs and chicken muscle

A competitive, direct, chemiluminescent enzyme-linked immunosorbent assay (CL-ELISA) for chloramphenicol (CAP) residues in milk, milk powder, honey, eggs and chicken muscle has been developed. The method gave a detection limit of 0.7 ng L−1 and a linear range of 2.1–92.4 ng L−1, with the IC50 of 13.6 ng L−1 under optimal conditions, dramatically better than any previously reported ELISA method for CAP detection. Spiked at levels of 5–60 ng L−1 in different food samples, recoveries were in the range of 72.1–116.0%, with coefficient of variations of 4.2–20.2%. In a study of incurred residues, the chicken muscle samples diluted 5-, 10- and 20-fold, results obtained by CL-ELISA correlated well with those obtained by gas chromatography with microcell electron capture detector and traditional ELISA. The developed CL-ELISA method is, therefore, suitable for rapid screening trace CAP residues in food samples.

Determination of chloramphenicol in milk by a fluorescence polarization immunoassay

A procedure for the determination of the drug chloramphenicol using a fluorescence polarization immunoassay (FPIA) was proposed. The optimum pairs of antibodies and antigens labeled with fluorescein were chosen, and the analytical characteristics of the procedure were determined. A rapid procedure for milk sample preparation with the use of a saturated solution of ammonium sulfate was optimized. The total time of sample preparation and determination of chloramphenicol in milk was no longer than 10 min. The detection limits of chloramphenicol in water and milk were 10 ng/mL and 20 μg/kg, respectively. The procedure developed for the determination of chloramphenicol was tested in the analysis of model and real milk samples. It was found that some milk samples contained chloramphenicol in concentrations of 38–41 μg/kg, which are several times higher than the maximum permissible concentration (MPC) (10 μg/kg).

Voltammetric determination of chloramphenicol in milk at electrochemically activated carbon fibre microelectrodes

Electrochemical activation of cylindrical carbon fibre microelectrodes (CFMEs) by repetitive square-wave (SW) voltammetric scans between 0.0 and +2.6 V has shown to increase dramatically the cathodic current of chloramphenicol (CAP). This is attributed to the increase of the carbon fibre surface area due to its fracture and the appearance of deep fissures along the main fibre axis. Cyclic voltammograms of CAP suggested a contribution to the total current from most likely thin-layer electrolysis. The current density:concentration ratio calculated for the reduction of CAP at an activated fibre was 6.5×10 7 μA cm −2 mol −1 l. A method for the determination of CAP at low concentrations levels, using SW voltammetry at electrochemically activated cylindrical microelectrodes, was developed. Different chemical and electrochemical variables involved in the activation step were optimised. Calibration graphs were linear ( r=0.9990) in the 1.0×10 −7 to 1.0×10 −5 mol l −1 concentration range, with a slope of (2.69+0.03) × 10 5 μA mol −1 l. A limit of detection of 4.7×10 −8 mol l −1 (15 ng ml −1) was found. The SWV method was applied for the determination of CAP in milk samples spiked with the antibiotic at two concentration levels: 64 and 320 ng ml −1. Recoveries >97% were obtained in all cases by following a very simple experimental procedure.

A Novel immunofluorescence capillary electrophoresis assay system for the determination of chloramphenicol in milk

An immunofluorescence capillary electrophoresis technique is described for the detection of chloramphenicol where the analyte was allowed to compete with a chloramphenicolfluorescein conjugate for binding to polyclonal anti‐chloramphenicol antibody. The bound and unbound forms of the chloramphenicol‐fluorescein conjugate were then analyzed by capillary zone electrophoresis with laser‐induced fluorescence detection, which permitted direct quantitation of the extent of immunocomplex formation. The amount of unbound conjugate in the reaction mixture was proportional to the quantity of chloramphenicol in the sample. Using this assay, it was possible to detect concentrations as low as 0.1–0.5 ng ml‐1 of chloramphenicol in a standard buffer and at least 01 ng ml‐1 of chloramphenicol in milk after extraction with ethyl acetate using a simple protocol. This highly sensitive procedure was rapid, requiring less than 30min to complete. The immunofluorescence capillary electrophoresis system should be similarly appli...