Simultaneous Determination and Identification of Furazolidone, Furaltadone, Nitrofurazone, and Nitrovin in Feeds by HPLC and LC‐MS

Silver nanopopcorns decorated on flexible membrane for SERS detection of nitrofurazone

The synthesis of three-dimensional silver nanopopcorns (Ag NPCs) onto a flexible polycarbonate membrane (PCM) for the detection of nitrofurazone (NFZ) on the fish surface by surface-enhanced Raman spectroscopy (SERS) is presented. The proposed flexible Ag-NPCs/PCM SERS substrate exhibits significant Raman signal intensity enhancement with the measured enhancement factor of 2.36 × 106. This is primarily attributed to the hotspots created on Ag NPCs, including numerous nanoscale protrusions and internal crevices distributed across the surface of Ag NPCs. The detection of NFZ by this flexible SERS substrate demonstrates a low limit of detection (LOD) of 3.7 × 10-9 M and uniform and reproducible Raman signal intensities with a relative standard deviation below 8.34%. It also exhibits excellent stability, retaining 70% of its efficacy even after 10 days of storage. Notably, the practical detection of NFZ in tap water, honey water, and fish surfaces achieves LOD values of 1.35 × 10-8 M, 5.76 × 10-7 M, and 3.61 × 10-8 M, respectively,  which highlights its effectiveness across different sample types. The developed Ag-NPCs/PCM SERS substrate presents promising potential for sensitive SERS detection of toxic substances in real-world samples.

Hierarchical 3D Snowflake-like Iron Diselenide: A Robust Electrocatalyst for Furaltadone Detection

An electrocatalyst with a large active site is critical for the development of a high-performance electrochemical sensor. This work demonstrates the fabrication of an iron diselenide (FeSe₂)-modified screen-printed carbon electrode (SPCE) for the electrochemical determination of furaltadone (FLD). It has been prepared by the facile method and systematically characterized with various microscopic/spectroscopic approaches. Due to advantageous physiochemical properties, the FeSe₂/SPCE showed a low charge-transfer resistance value of 200 Ω in 5.0 mM [Fe(CN)₆]^3-/4- containing 0.1 M KCl. More importantly, the FeSe₂/SPCE exhibited superior catalytic performance compared to the bare SPCE for FLD sensing based on the electrochemical response in terms of a peak potential of -0.44 V (vs Ag/AgCl (sat. KCl)) and cathodic response current of -22.8 μA. Operating at optimal conditions, the FeSe₂-modified electrode showed wide linearity from 0.01 to 252.2 μM with a limit of detection of 0.002 μM and sensitivity of 1.15 μA μM^-1 cm^-2. The analytical performance of the FeSe₂-based platform is significantly higher than many previously reported FLD electrochemical sensors. Furthermore, the FeSe₂/SPCE also has a promising platform for FLD detection with high sensitivity, good selectivity, excellent stability, and robust reproducibility. Thus, the finding above shows that the FeSe₂/SPCE is a highly suitable candidate for the electrochemical determination of glucose levels for real-time applications such as in human urine and river water samples.

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.

Improving sensitivity of antimicrobial drug nitrofurazone detection in food and biological samples based on nanostructured anatase-titania sheathed reduced graphene oxide

In this study, we have prepared anatase titanium (IV) oxide warped reduced graphene oxide nanocomposites (TiO₂-rGO NC) using ultrasonic methodology. The morphology of the TiO₂-rGO NC was studied using FESEM and TEM. In addition, XRD, Raman, thermogravimetric analysis (TGA) and XPS are used to analyze the crystallinity and chemical composition of the TiO₂-rGO NC. We have also investigated the electrochemical behavior of the as-prepared NCs with electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and different pulse voltammetry techniques (DPV). The TiO₂-rGO NC modified electrode shows the lower charge transfer resistance (R _ct ) of 62.87 Ω. Next, the glassy carbon electrode (GCE) was modified with sonochemically prepared TiO₂-rGO NC and used to determine the electrocatalytic reduction of nitrofurazone (NTF). Thus, the proposed sensor established the wider covering range (WCR) of 0.01 to 380 µM and an excellent detection limit of 2.28 nM. Finally, the TiO₂-rGO NC/GCE was applied to determine the NTF in real samples, including crayfish and human blood serum samples, which acquired good found and recovery values.

Residue depletion of nitrovin in chicken after oral administration

In this study, the residue depletion of nitrovin in chicken was studied after feeding the birds with dietary feeds containing 10 mg/kg of nitrovin for 7 consecutive days. Tissues (muscle, fat, kidney, and liver) and plasma were collected at different withdrawal periods and determined by a high-performance liquid chromatography-ultraviolet (HPLC-UV) method. The limit of detection for nitrovin in tissue and plasma samples was 0.1 ng/(g or mL), and the inter- and intrarecoveries from the blank fortified samples were in the range of 71.1-85.7%. At the withdrawal period of 0 days, the residue concentration of nitrovin in plasma was the highest (average of 84.98 ng/mL) compared to those in muscle, fat, liver, and kidney (average of 21.04, 61.18, 24.04, and 68.28 ng/g, respectively). At the withdrawal period of 28 days, the residue levels of nitrovin in muscle, fat, liver, and plasma were all higher than 1.0 ng/(g or mL) and the highest concentration was in liver (average of 5.8 ng/g). These data are in support of the ban of nitrovin as a feed additive in food-producing animals.

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.

Recent studies of the electrospray ionisation behaviour of selected drugs and their application in capillary electrophoresis–mass spectrometry and liquid chromatography–mass spectrometry

This review is concerned with recent studies of electrospray ionisation-mass spectrometry (ESI-MS) of selected small molecular mass drugs and their application in qualitative and quantitative analytical methods using the techniques liquid chromatography mass spectrometry (LC-ESI-MS) and capillary electrophoresis mass spectrometry (CE-ESI-MS). The publications reviewed are taken from the Web of Knowledge database for the year 2006. The drugs have molecular mass less than 1000 Da and are chosen according to selected drug classifications in which they give ESI signals primarily as [M+H]+ ions. The drug classifications are antibiotics/antibacterials, steroids, anti-tumour drugs, erectile dysfunction agents, anti-epileptic drugs, antiasthmatic drugs, psychoactive drugs and miscellaneous drugs. Details are given on the fragmentations, where available, that these ionic species exhibit in-source and in ion trap, triple quadrupole and time-of-flight mass spectrometers. Analytical methods for the detection and determination of these small molecular mass drug molecules are also discussed, where appropriate, under the particular drug classifications. Analytical information on, for example, sample concentration techniques, separation conditions, recoveries from biological media and limits of detection/quantitation (LODs and LOQs) are provided.