Tetracycline Antibiotic Residues Research Articles

A study on fast detection methods for tetracycline antibiotic residues based on magnetic nanoparticles and electrochemical aptasensors

This study presents the development of novel electrochemical aptasensors utilizing magnetic nanomaterials for rapid and sensitive detection of tetracycline (TET) antibiotic residues. Two types of nanocomposites, Cu2O@Au octahedral nanoparticles and rGO-Fe3O4, were synthesized and characterized for aptasensor fabrication. The Cu2O@Au-based aptasensor demonstrated a linear detection range from 1 nM to 1 μM, with a limit of detection (LOD) of 0.3 nM. The rGO-Fe3O4/sodium alginate-based aptasensor exhibited a linear range of 5 nM to 500 nM, with an LOD of 1.5 nM. Both aptasensors showed excellent specificity towards TET, good reproducibility (RSD < 5.6 %), and stability (>90 % response after 2 weeks). The practical applicability of the aptasensors was validated through TET detection in spiked milk samples, achieving recoveries between 88.6 % and 107.8 % with RSDs below 7.2 %. These aptasensors offer advantages such as rapid response, simple fabrication, and potential for on-site detection, making them promising tools for food safety monitoring and environmental surveillance.

Strip biosensors based on broad-spectrum aptamers and cationic polymers for the on-site rapid detection of tetracycline antibiotics residues in milk

A lateral flow chromatography strip (LFS) is a chromatography-based biosensor with advantages of convenient carrying, simple operation and rapid detection. In this study, a novel rapid detection technique of aptamer-based chromatography strip was developed and used for the first time for the residue detection of tetracycline antibiotics (TCs) in various milk samples. In this method, gold nanoparticles (AuNPs) modified by TCs specific aptamers were used as probes, and cationic polymers as a capture molecule in a test line (T-line). Meanwhile, the analysis of the gray value of the T-line enabled a linear detection range of 1–300 nM and a limit of detection (LOD) of 0.33 nM for quantitative analysis. The biosensor demonstrated specificity, stability, and successfully detected tetracyclines in milk samples with recovery between 93.60 %–106.20 %. This method sets a basis for multi-residue antibiotics detection in diverse samples, showing potential for on-site applications.

Underestimation of tetracycline antibiotic residues in chicken meat: The role of protein binding

Interesting variations in the analyte content were observed in chicken samples contaminated with tetracycline antibiotics (TCs) following pretreatment with various enzymatic hydrolysis before quantification by conventional analytical methods. Compared with untreated samples, the detectable contents of three TCs in protease-treated samples were 1.51 to 2.05 times higher, whereas lipase treatment did not significantly influence the contents. The marked changes following protease treatment confirmed the presence of protein-associated antibiotics. Infrared spectroscopy analysis indicated that the formation of protein-bound antibiotics resulted from non-covalent interactions between TCs and proteins. Further dissociation experiments determined that the intermolecular forces involved hydrogen bonding, hydrophobic interactions, and electrostatic attraction. Molecular docking substantiated these forces and detailed the binding mechanism at the molecular level. Moreover, the masking effect of protein binding on the determination of TCs was also evidenced in an additional 30 positive chicken samples, suggesting that the actual residue levels of TCs in protein-rich foodstuff are underestimated.

A highly efficient molecularly imprinted fluorescence sensor for selective and sensitive detection of tetracycline antibiotic residues in pork

Tetracyclines (TCs) residues in animal-based foods may cause consumer poisoning or allergic reactions, as well as resistance of pathogenic microorganisms. Therefore, a method to accurately monitor TCs is urgently needed. Here, a sensitive and greenificated molecularly imprinted fluorescent sensor (CDs@MIP) for detecting TCs residues using non-covalent imprinting binding method has been synthesized in a simple and safe manner. The sensor was demonstrated to contain specific adsorption sites and high adsorption capacity by static adsorption test results and Freundlich and Langmuir model analyses, and the maximum adsorption capacity was 45.8 mg/g. Moreover, the sensor exhibited intense blue-green fluorescence under UV light, and the fluorescence was gradually quenched as TCs was adsorbed to achieve the detection. The fluorescent spectrum experiment demonstrated that the prepared sensor has good recognition and detection performance for TCs with a linear range of 0.02–50 mg/L and a detection limit of 0.18 μg/L. Furthermore, This sensor is recyclable and can be used to determine TCs content in pork with a recovery rate of 98 %–108 %. Therefore, the constructed sensor provides a new convenient strategy for detecting TCs residues.

A novel fluorescence platform for specific detection of tetracycline antibiotics based on [MQDA-Eu3+] system

Tetracycline antibiotics (TCs) are extensively used in clinical medicine, animal husbandry, and aquaculture because of their cost-effectiveness and high antibacterial efficacy. However, the presence of TCs residues in the environment poses risks to humans. In this study, an inner filter effect (IFE) fluorescent probe, 2,2′-(ethane-1,2-diylbis((2-((2-methylquinolin-8-yl)amino)-2-oxoethyl)azanediyl))diacetic acid (MQDA), was developed for the rapid detection of Eu3+ within 30 s. And its complex [MQDA–Eu3+] was successfully used for the detection of TCs. Upon coordination of a carboxyl of MQDA with Eu3+ to form a [MQDA–Eu3+] complex, the carboxyl served as an antenna ligand for the effective detection of Eu3+ to intensify the emission intensity of MQDA via “antenna effect”, the process was the energy absorbed by TCs via UV excitation was effectively transferred to Eu3+. Fluorescence quenching of the [MQDA–Eu3+] complex was caused by the IFE in multicolor fluorescence systems. The limits of detection of [MQDA–Eu3+] for oxytetracycline, chlorotetracycline hydrochloride, and tetracycline were 0.80, 0.93, and 1.7 μM in DMSO/HEPES (7:3, v/v, pH = 7.0), respectively. [MQDA–Eu3+] demonstrated sensitive detection of TCs in environmental and food samples with satisfactory recoveries and exhibited excellent imaging capabilities for TCs in living cells and zebrafish with low cytotoxicity. The proposed approach demonstrated considerable potential for the quantitative detection of TCs.

Validation of an efficient analytical method for quantification of tetracycline antibiotic residues in egg samples along with investigating their decontamination using ultraviolet waves

ABSTRACT This study describes the development and application of a dispersive solid-phase extraction procedure combined with dispersive liquid – liquid microextraction for the extraction of tetracycline antibiotics from egg samples. In this method, a bio-metal organic framework was prepared and used in extraction of the analytes from sample solution. In this method, the sorbent synthesis was relatively easy and its crosslinker was vitamin B3 which is a green chemical compound. The sorbent provides particles can extract the analytes via interactions such as surface adsorption, occlusion van der waals and π–π interactions. The extraction procedure was done by mixing trichloroacetic acid with the egg sample to remove the sample proteins and then the synthesised sorbent at mg – level was added to the supernatant phase and the mixture was vortexed. After centrifuging, the supernatant phase was removed and sorbent particles containing the extracted analytes were eluted using acetonitrile. After that, this phase containing the analytes was taken and used in the following dispersive liquid – liquid microextraction process that was done to more enrichment the analytes using a deep eutectic solvent. After optimisation of the extraction process, sensitive limits of detection and quantification were found in the ranges of 0.21–0.28 and 0.70–0.93 ng g−1, respectively. Acceptable extraction recoveries of the analytes ranged from 60 to 73%. The method was selective regarding the analytes, as there were no interfering peaks eluted at the retention times of the analytes. After the validation step, the offered method was employed for the determination of the tetracycline antibiotics in various egg samples and the effect of ultraviolet waves in decontaminating them from egg samples was investigated.

QUALITY CHARACTERISTICS OF RAW MILK SAMPLES PURCHASED FROM AUTOMATIC MİLK VENDING MACHINES IN NİĞDE PROVINCE

In the regulation published by the Ministry of Agriculture and Forestry in Turkey, it is stated that only automatic milk machines can be used to put raw milk on sale. This study aims to examine some physical, chemical and microbiological properties of a total of 40 raw milk samples sold in automatic vending machines and unpackaged, by egulations in Niğde province, and to compare the milk samples according to the retailer from which they were purchased. The study also aimed to quantitatively determine carbonate and hydrogen peroxide residues in milk samples and the presence of beta-lactam and tetracycline group antibiotics with a commercial kit. At the end of the study, the average value of lactic acid (%) density, fat, protein, non-fat dry matter, lactose, freezing point and pH values of the samples were determined as 0.153% ± (0.022); 1.028± (0.03) g/ml; 3.525%± (0.656); 3.5%± (0.107); 9% 4± (0.277); 5.134± (0.152); -0.549°C ± (0.018) and 6.55 ± (0.102) respectively. As a result of microbiological analysis of milk, the average number of total aerobic mesophilic organisms, coliforms, fecal coliforms, yeast-molds and micrococci-staphylococci was determined as 5.38 ± (0.47); 3.73 ± (1.11); 2.76 ± (1.66); 2.33 ± (1.86) and 4.29± (1.20) log cfu/ml respectively. Carbonate, hydrogen peroxide, beta-lactam and tetracycline antibiotic residues could not be detected in the milk samples. The fact that some of the results obtained in the study were outside the limits specified in the codexes and different from the study average reveals that the milk sold in businesses selling street milk should be analyzed regularly.

Nanozyme-induced deep learning-assisted smartphone integrated colorimetric and fluorometric dual-mode for detection of tetracycline analogs

In this work, a colorimetric and fluorescent dual-mode probe controlled by NH2-MIL-88 B (Fe, Ni) nanozymes was developed to visually detect tetracycline antibiotics (TCs) residues quantitatively, as well as accurately distinguish the four most widely used tetracycline analogs (tetracycline (TC), chrycline (CTC), oxytetracycline (OTC), and doxycycline (DC)). Colorless substrate 3,3′,5,5′-tetramethylbenzidine (TMB) may be oxidized to blue oxidized TMB by the Fe Fenton reaction, which was catalyzed by the NH2-MIL-88 B (Fe, Ni) nanozyme with POD-like activity. The colorimetric detection system allows TCs to interact with NH2-MIL-88 B (Fe, Ni). This inhibits the production of ·OH, weakens the oxidation process of TMB, and ultimately lightens the blue color in the system by blocking the electron transfer between NH2-MIL-88 B (Fe, Ni) and H2O2. Furthermore, TCs can interact with NH2-MIL-88 B (Fe, Ni) as a result of the internal filtering effect, which causes the fluorescence intensity to decrease as TCs concentration increases. Additionally, a portable instrument that combines a smartphone sensing platform with colorimetric and fluorescent signals was created for the quick, visual quantitative detection of TCs. The colorimetric and fluorescent dual-mode nano platform enables color change, with detection limits (LODs) of 0.182 μM and 0.0668 μM for the spectrometer and smartphone sensor, respectively, based on the inhibition of fluorescence and enzyme-like activities by TCs. Overall, the colorimetric and fluorescence dual-mode sensor has good stability, high specificity, and an efficient way to eliminate false-positive issues associated with a single detection mode.

Conjugation of tetracycline with carrier proteins and production of its polyclonal antibody for the development of rapid test

Tetracycline (TC) is a broad-spectrum antibiotic used in the treatment of several infectious diseases. The excessive use of tetracycline antibiotics, especially tetracyclines in livestock, has raised concerns about residues of tetracycline antibiotics in food that may affect consumers' health. It is necessary to develop a rapid test strip for detecting tetracycline antibiotic residues in food and animal feed. This paper presents the suitable conditions for the conjugation of tetracycline to BSA or KLH: molar ratio of TC:BSA/KLH was 25:1, formaldehyde concentration of 5 %, temperature of 4oC and reaction time of 4 hours. The KLH-TC conjugate was used to successfully raise polyclonal antibodies against TC in rabbits. The anti-TC polyclonal antibodies were purified and could be used for the development of the lateral flow immunoassay test strip for the detection of tetracycline.

Detection of antibiotic residues in broiler chicken meat in traditional markets in Surakarta City

This research aims to detect the presence of penicillin, tetracycline, aminoglycoside, and macrolide antibiotic residues in broiler chicken meat sold in traditional markets in Surakarta City. A total of 60 research samples were collected from traditional markets. Subsequently, the samples were examined at BBVet Wates, Yogyakarta, to identify the presence of antibiotic residues. The results showed that 16.67% of the chicken breast meat samples tested positive for penicillin and 10% showed traces of macrolide antibiotic residues. For chicken thigh meat, 63.33% tested positive for penicillin, while 3.33% contained macrolide antibiotic residues. However, no tetracycline and aminoglycoside antibiotic residues were detected in any of the meat samples. The presence of antibiotic residues can be attributed to several factors, including the excessive addition of antibiotics in feed, improper use of antibiotics in livestock. Based on the research results, it can be concluded that penicillin and macrolide antibiotic residues are still prevalent in broiler chicken meat sold in traditional markets in Surakarta. This shows there is a pressing need to strengthen guidance and supervision of antibiotic use regulations, as well as to monitor antibiotic residues in the meat before it reaches the market.

Screening of broad-spectrum aptamers to construct an electrochemical aptasensor for the sensitive detection of tetracycline antibiotic residues in milk

Broad-spectrum aptamer has been shown to be an important probe for antibiotic multi-residue detection. In this study, we successfully screened a broad-spectrum aptamer (Apt-T1) that can recognize TCs with the same core structure using the graphene oxide (GO)-SELEX. Then Apt-T1 was truncated by molecular docking simulation to obtain an aptamer (Apt-T1–2) with higher specificity and affinity with a dissociation constant of 4.27–7.20 nM. On this basis, an electrochemical aptasensor based on Apt-T1–2 was constructed to achieve sensitive detection of TCs. Fe/ Zn-doped montmorillonite was synthesized by cation exchange technique for amplifying sensor signal. Under optimized conditions, the aptasensor showed a limit of detection of 0.46 nM and a linear range of 1–10,000 nM with a correlation coefficient (R2) of 0.989. Finally, the effects of the main components (fat, protein, Na+ and Ca2+) in milk on the electrochemical signal were investigated, and it was clear that fat and protein had a negative effect and so they were removed. The method was used to the determination of TCs in milk with recoveries of 98.26%− 104.15%, which revealed its potential application for sensitive analysis in food safety control and also provided a new method for multi-residue detection of antibiotics in milk.

Optimization of QuEChERS Method for Antibiotic Residue Analysis in Animal Foods via Response Surface Methodology

The present study employed a modified QuEChERS method to systematically analyze the presence of fifteen quinolone and seven tetracycline antibiotic residues in local animal food. Additionally, a multi-level four-factor Box–Behnken design (BBD) within the framework of response surface methodology (RSM) was utilized to evaluate the factors impacting the detection efficiency of the sample pretreatment procedure. Optimization was performed via Design Expert® 10.0.3, and the factors, including the volume of the acetonitrile, the addition of formic acid, the duration of the extraction, and the addition of EDTA, were combined with experimental design until an optimal solution was reached. Finally, the sample was tested via ultra-high performance liquid chromatography-quadrupole-linear ion trap mass spectrometry (UPLC/MS/MS) in both multiple reaction monitoring (MRM) and enhanced product ion (EPI) scan modes on a QTRAP® 5500 instrument (AB SCIEX instruments, Framingham, MA, USA). The overall average recoveries from actual samples fortified with 22 antibiotics at three levels ranged from 73.8% to 98.5% based on the use of matrix-fortified calibration, with variations ranging from 5.80 to 12.4% (n = 6). The limits of detection and quantification were 0.3 μg kg−1 and 1.0 μg kg−1, respectively. Lastly, the modified method was applied to practical sample analysis in the daily risk monitoring and assessment of food safety with satisfactory stability and robustness.

Effects of the coexistence of antibiotics and heavy metals on the fate of antibiotic resistance genes in chicken manure and surrounding soils

Both heavy metals and antibiotics exert selection pressure on bacterial resistance, and as they are commonly co-contaminated in the environment, they may play a larger role in bacterial resistance. This study examined how breeding cycles affect antibiotic resistance genes (ARGs) in chicken manure and the surrounding topsoils at 20, 50, 100, 200, and 300 m from twelve typical laying hen farms in the Ningxia Hui Autonomous Region of northwest China. Six antibiotics, seven heavy metals, ten mobile genetic elements (MGEs), and microbial community affected the ARGs profile in chicken dung and soil samples. Tetracycline antibiotic residues were prevalent in chicken manure, as were relatively high content of aureomycin during each culture period. Zinc (Zn) content was highest among the seven heavy metals in chicken feces. Chicken dung also enriched aminoglycosides, MLSB, and tetracycline ARGs, notably during brooding and high production. The farm had a minimal influence on antibiotics in the surrounding soil, but its effect on ARGs and MGEs closer to the farm (50 m) was stronger, and several ARGs and MGEs increased with distance. Manure microbial composition differed dramatically throughout breeding cycles and sampling distances. ARGs were more strongly related with antibiotics and heavy metals in manure than soil, whereas MGEs were the reverse. Antibiotics, heavy metals, MGEs, and bacteria in manure accounted 12.28%, 22.25%, 0.74%, and 0.19% of ARGs composition variance, respectively, according to RDA and VPA. Bacteria (2.89%) and MGEs (2.82%) only affected soil ARGs composition. These findings showed that heavy metals and antibiotics are the main factors affecting faecal ARGs and bacteria and MGEs soil ARGs. This paper includes antibiotic resistance data for large-scale laying hen husbandry in northwest China and a theoretical framework for decreasing antibiotic resistance.

Plant extracts-mediated green synthesis of zinc oxide/carbon nanofiber nanocomposites with highly efficient photocatalytic and antimicrobial properties for wastewater treatment

In the present study, a novel biosynthesis method for the preparation of zinc oxide/carbon nanofiber nanocomposite (ZnO-CNFs) is proposed along with evaluated their photocatalytic and antimicrobial properties for wastewater treatment. For biosynthesis of ZnO-CNFs, plant extracts of Thymus daenensis (TD) and Stachys pilifera Benth (SB) were used as both green-reducing agents and aqueous carbon-rich sources. The photocatalytic activity of the synthesized ZnO-CNFs was studied in the photodegradation of tetracycline antibiotic residues in contaminated water. The photocatalytic test (UVA irradiation, λ = 365 nm) results showed that the photodegradation efficiency of tetracycline by ZnO-CNFTD was 93.65 ± 2.1 %, 73.58 ± 1.5 %, 67.41 ± 1.7 %, and 81.28 ± 2.1 % in ultrapure water, infectious disease hospital 1, infectious disease hospital 2, and general hospital influents, respectively. Furthermore, the antimicrobial activity was examined against Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) bacteria and Candida albicans (C. albicans) fungus. To this end, the antibacterial behaviors of ZnO-CNFs were studied based on minimal inhibitory concentration (MIC) ranges and diameter of inhibition zone, which indicated that the ZnO-CNFs exhibited superior antibacterial activity against Gram-positive (B. subtilis) and Gram-negative (E. coli) bacteria compared to ZnO nanoparticles. Also, the antifungal activity of ZnO-CNFTD with MIC range of 156.25–625 μg mL−1 was more potent than ZnO nanoparticles with MIC range of 156.25–2500 μg mL−1. Overall, our findings indicate that the synthesized ZnO-CNFTD exhibits excellent photocatalytic and antimicrobial potential compared to ZnO nanoparticles and therefore can be a promising candidate for effective treatment of water contaminated with microorganisms and organic compounds.

Towards selective tetracycline recognition in wastewater based on gold nanovoids@aptamer sensing

In recent years, tetracycline antibiotic residues in food and water have been of great concern to regulators and consumers, with adverse effects on both ecosystems and human health. In this work, we developed a novel 3D honeycombed goldnanovoids@aptamer nanostructured platform with biorecognition and signal enhancement properties for the detection of tetracycline. Direct electrochemical detection was enabled by differential pulse voltammetry through the Ferrocene redox label at the aptamer strands which was effectively influenced by the tetracycline-aptamer specific interaction. The aptasensor can detect tetracycline at a concentration from 1.25∙10−8 M to 1.00∙10−6 M, and the limit of detection and limit of quantification were calculated as 1.20∙10−9 M (0.53 ng/mL) and 4.23∙10−9 M (1.87 ng/mL), respectively. Furthermore, the aptasensor presented excellent selectivity in detecting tetracycline in the presence of various interference analytes. In addition, the proposed sensor proved its practical feasibility to quickly and accurately quantify tetracycline residues in wastewater samples with satisfactory recoveries (from 93.18 to 112.64 %, RSD 1.12 % – 6.13 %). We have designed and synthesized a 3D honeycombed gold nanostructured platform for the highly tailored aptamer functionalization for the specific detection of tetracycline, expanding the range of electrochemical detection aptasensors and offering great promise for in-situ water monitoring.

Keberadaan Residu Tetrasiklin pada Daging Ayam Broiler di Kabupaten Kudus (Studi di Pasar Tradisional dan Pasar Modern Tahun 2019)

Background: One of the causes of antibiotic resistance is the presence of antibiotic residues in livestock, one of which is broiler chicken meat. Excessive use of antibiotics and not in accordance with the diagnosis will result in the discovery of antibiotic residue content in chicken meat and will endanger public health. The purpose of this study was to determine the description of the antibiotic residues of tetracycline in broiler chicken meat sold in traditional and modern markets in Jati District, Kudus Regency.Methods: This type of research is a descriptive observational study with a cross-sectional approach. The samples in this study were all broiler chicken meat sold in traditional markets (Bitingan Market, Sunggingan Ploso Market, and Baru Market) and in the modern Hypermart market with a total sample of 78 samples of broiler chicken meat taken with total population sampling technique. Sample testing was carried out at Balai Veteriner Boyolali using the Bioassay method.Result: Based on the results of the study, there is no tetracycline antibiotic residues were found in 78 (100%) broiler chicken meats sold in the Bitingan Market, Sunggingan Ploso Market, Baru Market, and Hypermart.Conclusion : There is no tetracycline antibiotic residues were found in broiler chicken meat sold in the Bitingan Market, Sunggingan Ploso Market, Baru Market, and Hypermart.

The Source and Distribution of Tetracycline Antibiotics in China: A Review

In recent years, antibiotics have been listed as a new class of environmental pollutants. Tetracycline antibiotics (TCs) used in human medical treatment, animal husbandry and agricultural production are the most widely used antibiotics. Due to their wide range of activities and low cost, their annual consumption is increasing. TCs cannot be completely metabolized by humans and animals. They can be abused or overused, causing the continuous accumulation of TCs in the ecological environment and potential negative effects on non-target organisms. These TCs may spread into the food chain and pose a serious threat to human health and the ecology. Based on the Chinese environment, the residues of TCs in feces, sewage, sludge, soil and water were comprehensively summarized, as well as the potential transmission capacity of air. This paper collected the concentrations of TCs in different media in the Chinese environment, contributing to the collection of a TC pollutant database in China, and facilitating the monitoring and treatment of pollutants in the future.

Recent advances in luminescence and aptamer sensors based analytical determination, adsorptive removal, degradation of the tetracycline antibiotics, an overview and outlook

Tetracycline antibiotics (TCs), one of the important antibiotic groups, have been widely used in human and veterinary medicines. Their residues in foodstuff, soil and sewage have caused serious threats to food safety, ecological environment and human health. Here, we reviewed the potential harms of TCs residues to foodstuff, environment and human beings, discussed the luminescence and aptamer sensors based analytical determination, adsorptive removal, and degradation strategies of TCs residues from a recent 5-year period. The advantages and intrinsic limitations of these strategies have been compared and discussed, the potential challenges and opportunities in TCs residues degradation have also been deliberated and explored.

Interfacial configuration and mechanism insights of an all-solid-state Z-scheme BaTiO3/Bi/Bi2O3 heterojunctions for rapid removal of tetracycline antibiotics

Photocatalytic technology based on efficient-economic heterojunction catalysts has been considered a promising approach to remove the discharged tetracycline (TC) antibiotic residues in contaminated water. However, unveiling an effective interface configuration with a clear mechanism is still the toughest challenge for heterojunction photocatalysts. Through a facile route of hydrothermal and heat treatment for the first time, herein, we reported an all-solid-state Z-scheme heterojunction of BaTiO3/Bi/Bi2O3 (BT/Bi/BO) with a conspicuous light response and efficient photo-excited carrier kinetics (high separation and redox ability). It performed a stable and ultrahigh photocatalytic activity toward removing TC, which can be quickly degraded in a few minutes. Density functional theory calculation on heterogeneous interface confirmed that the metallic Bi at the interlayer played a critical role in the excellent photocatalytic performance. The interlayer Bi not only promoted the adhesion between BT and BO to enhance the structural stability, but also had a strong interaction with O atoms of BT to reduce the band gaps to improve the light response. Moreover, its p band located in the band gaps can assist the Z-scheme transfer of photo-excited carriers under an interfacial built-in electronic field of the heterojunction. Therefore, this work provides a new perspective and deep understanding of the configuration and interfacial mechanism of Z-scheme heterogeneous photocatalysts for the removal of antibiotics.

Simultaneous Determination of Four Tetracycline Antibiotics Residues in Chicken by Solid Phase Extraction Coupled with High Performance Liquid Chromatography

Objective: To establish a simple and rapid method for simultaneous determination of Tetracycline, Oxytetracycline, Chlortetracycline and Doxycycline in chicken. Methods: After optimized sample pretreatment and chromatographic conditions, tetracycline antibiotics in spiked chicken were extracted by ultrasonic extraction with Na2EDTA-Mcllvaine buffer solution (pH=4.0), purified and enriched by HLB solid phase extraction column, separated by Shim-pack GIST C18 column (4.6&amp;times;150 mm, 3 &amp;mu;m), methanol-acetonitrile-oxalic acid (1:2:7, V: V: V) as the mobile phase, the flow rate was 0.9 mL/min, the UV detection wavelength was 350 nm, and the peak area was quantified by external standard method. Results: The linearity of the four tetracycline antibiotics was good in the range of 0.05-1 mg/kg (r＞0.997), and the detection limits were 2.53 &amp;mu;g/kg ~ 5.94 &amp;mu;g/kg according to the S/N ratio (S/N) of 3. The relative standard deviations (RSD, n=6) of precision were 1.51%-4.80%. The recoveries were from 76.81% to 96.34%. Conclusion: The method has good selectivity, high accuracy and reproducibility, and is suitable for simultaneous determination of four tetracycline antibiotics in chicken.