Swine Urine Research Articles

Optimization, validation, and application of a liquid chromatography-tandem mass spectrometry method for the determination of 47 banned drug and related chemical residues in livestock urine using graphitized carboxyl multi-walled carbon nanotubes-based QuEChERS extraction

The establishment of an efficient method for the analysis of drug residues in animal urine facilitates the real-time monitoring of drugs used in the production of animal-derived food. A modified QuEChERS extraction–liquid chromatography-tandem mass spectrometry (LC–MS/MS) method was established for the determination of 47 banned drug and related chemical residues in livestock urine. The sample was extracted with acetonitrile by converting the acid-base environment. The sample cleanup effects of seven solid phase extraction cartridges and two EMR-Lipid products were compared, and three materials, including graphitized carboxyl multi-walled carbon nanotubes (MWCNTs), PSA, and C18, were selected as QuEChERS adsorbents from 24 materials. All analytes showed good linearity, with correlation coefficients (R2) greater than 0.9936. Low limits of quantification could be obtained, ranging from 0.2 to 5.5 ng/mL. The average recoveries at low, medium, and high spiked levels were in the range of 70.8–114.9 %, with intra-day precision ranging from 2.4 % to 11.2 % and inter-day precision ranging from 4.5 % to 16.1 %. Swine urine and bovine urine samples collected from different farms were effectively analyzed using the developed method, and metronidazole was detected in three swine urine samples.

Four birds with one stone: Aggregation-induced emission-type zeolitic imidazolate framework-8 based bionic nanoreactor for portable detection of olaquindox in environmental water and swine urine by smartphone

The abuse of olaquindox (OLA) as both an antimicrobial agent and a growth promoter poses significant threats to the environment and human health. While nanoreactors have proven effective in hazard detection, their widespread adoption has been hindered by tedious chemical processes and limited functionality. In this study, we introduce a novel green self-assembly strategy utilizing invertase, horseradish peroxidase, antibodies, and gold nanoclusters to form an aggregation-induced emission-type zeolitic imidazolate framework-8 nanoreactor. The results demonstrate that the lateral flow immunoassay not only allows for qualitative naked eye detection but also enables optical analysis through the fluorescence generated by aggregated gold nanoclusters and enzyme-catalyzed enhancement of visible colorimetric signals. To accommodate more detection scenarios, the photothermal effects and redox reactions of the nanoreactor can fulfill the requirements of thermal sensing and electrochemical analysis for smartphone applications. Remarkably, the proposed approach achieves a detection limit 17 times lower than conventional methods. Besides, the maximum linear range spans from 0.25 to 5 μg/L with high specificity, and the recovery is 85.2–112.9% in environmental water and swine urine. The application of this high-performance nanoreactor opens up avenues for the construction of multifunctional biosensors with great potential in monitoring hazardous materials.

CdTe based water-soluble fluorescent probe for rapid detection of zilpaterol in swine urine and pork

Zilpaterol hydrochloride (zilpaterol) is used in animal feed as it can increase the lean meat mass. However, consuming zilpaterol-containing animal products may damage human health. Therefore, rapid detection of zilpaterol is attracting increasing research attention. This study aimed to developed a fast, accurate, and ultrasensitive fluorescence immunoassay based on CdTe quantum dots (QDs). A CdTe QD fluorescence sensor was synthesized from thioglycolic acid using a simple hydrothermal method. The morphology and structure of the CdTe QDs were characterized using transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy. The detection limits of our method in swine urine and pork samples were 0.5 μg/L and 1.2 μg/kg, respectively. A wide linear range of 0.1–10000 μg/L (R2 = 0.996) was achieved. Both within-run precision (CVw) and between-run precision (CVb) were ≤ 10 %. The method was then successfully applied for the analysis of zilpaterol contents in swine urine and pork samples.

Electrochemical determination of salbutamol in aqueous solutions with UiO‐66/rGO‐modified electrodes

AbstractThe synthesis of the UiO‐66/rGO material involved combining UiO‐66 with reduced graphene oxide (rGO). This resulting composite found application in the electrochemical determination of salbutamol (SAL) through modification of a glassy‐carbon electrode (GCE) with UiO‐66/rGO. Differential pulse voltammetry served as the chosen technique, offering a wide linear range spanning 1–160 µm and demonstrating a low limit of detection at 0.84 µm. To ensure the reliability of the electrode, various aspects such as sensitivity, repeatability, reproducibility, and stability were meticulously studied. When applied to the analysis of SAL in swine urine solutions (n = 3), the electrode exhibited good recovery rates. Remarkably, the results obtained through this method correlated well with those acquired using ultra‐high performance liquid chromatography (UPLC).

Establishment of a modified QuEChERS extraction and liquid chromatography-tandem mass spectrometry method for multiple pesticide residues followed by determination of the residue levels and exposure assessment in livestock urine

The establishment of an analytical method for pesticide residues in livestock urine can realize the real-time monitoring of pesticide pollution in livestock breeding. In this study, a novel method was developed for the determination of 106 pesticide residues in livestock urine based on a modified QuEChERS extraction and liquid chromatography–tandem mass spectrometry. Acetonitrile was used to extract target analytes through acidic and alkaline switching of the sample environment. The purification effect of captiva EMR-Lipid on samples was investigated. Three kinds of materials, C18, polar enhanced polymer (PEP), N-propylethylenediamine (PSA), were selected from 20 kinds of materials as adsorbents for QuEChERS. A mass analysis was carried out using simultaneous scanning in both positive and negative ion mode and multiple reaction monitoring mode. All analytes showed good linearity, with correlation coefficients (R2) greater than 0.9923; their limits of quantification were 0.02–1.95 ng/mL. The average recoveries at low, medium, and high spiked levels were in the range of 70.1 %–117.3 %, with intra-day precision ranging from 3.4 % to 16.9 % and inter-day precision ranging from 4.0 % to 19.3 %. The established analytical method was used to analyze the pesticide residue in swine urine and bovine urine collected from farms in Yining, Xinjiang, China. A total of 8 pesticides were detected, and the residue ranged from less than the limit of quantitation to 22.4 ng/mL. The top three pesticides with the highest detection frequency were clothianidin, thiamethoxam, and dinotefuran. The exposure assessment based on the monitored pesticide residue concentration levels showed that the detected pesticides could pose little risk to cattle and pigs.

Sensitive and smartphone-assisted visual detection of oxytetracycline by a ratiometric fluorescence sensor based on nitrogen-doped carbon quantum dots from banana peel cooperating with europium

Oxytetracycline (OTC) residues have serious adverse effects on human health. Thus, selective and sensitive field detection methods are needed. Here, we successfully synthesized nitrogen-doped carbon quantum dots (N-CQDs) with good water-solubility, prominent fluorescence (FL), and favorable stability via a one-step hydrothermal method using banana peel as a carbon source and diethylenetriamine as a nitrogen source. We used the N-CQDs to create a ratiometric FL probe by self-assembling them with europium ions (Eu3+), enabling OTC detection. The FL intensity of N-CQDs at 445 nm was quenched due to the inner filter effect, while the FL intensity of Eu3+ at 621 nm markedly increased via the antenna effect upon OTC introduction. The ratiometric FL sensor demonstrated two linear relationships with OTC concentrations, ranging from 0.01 to 5 μg mL−1 and 5 to 25 μg mL−1, with a limit-of-detection of 4.9 ng mL−1 for OTC. Additionally, this platform depicted an apparent color change from blue to purple under a 365 nm ultraviolet–visible lamp, and a visual semi-quantitative analysis of OTC was achieved using a mobile phone application. We successfully implemented this method to detect OTC in pork muscle and swine urine, achieving remarkable recovery results (96.89–103.20%). Therefore, our findings demonstrate the potential of this approach for real-time and semi-quantitative OTC detection.

Two kinds of lateral flow immunoassays based on multifunctional magnetic prussian blue nanoenzyme and colloidal gold for the detection of 38 β-agonists in swine urine and pork.

Herein, novel multifunctional magnetic prussian blue nanoenzymes (MPBNs) and colloidal gold (CG) were synthesized and used to develop two kinds of lateral flow immunoassays (LFIAs) for the detection of 38 β-agonists. Since MPBNs has a unique three-in-one function of colorimetric magnetic catalytic activities, the signal intensity and coupling ratio are 2 and 8-fold higher than that of the CG. The cut-off values of the CG-LFIA and MPBNs-LFIA for swine urine and pork are 5/5 and 0.3/0.5μg/kg, the limits of detection are 0.19/0.29 and 0.02/0.03μg/kg, respectively. The sensitivity of MPBNs-LFIA is 10-fold higher than that of CG-LFIA, and up to 200-fold higher than that of the reported LFIAs. The recoveries of the LFIAs are 80.0%-116.7%, with coefficients of variation of 1.4%-14.3%. Our study proved that the MPBNs have more advantages than CG, and can offer a promising signal label for ultrasensitive immunoassay techniques.

Honeycomb-like MnO2/Biochar Catalyst Fabricated by High-Energy Electron Beam Irradiation for Degradation of Antibiotics in Swine Urine.

The modification of biochar is essential for the development of multifunctional biochar materials with enhanced remediation effects on contaminated water. In this work, a biochar-based microcatalyst with sunlight sensitivity was synthesized by a creative modification method that involved the rapid fabrication of MnO2 microspheres by high-energy electron beam (HEEB) irradiation, and loading them into corn straw-derived honeycomb-like KOH-modified biochar (MBC) to obtain a sunlight-sensitive microcatalyst (SSM). The honeycomb-like structure of MBC facilitated the improvement in MnO2 dispersion and photocatalytic property through confinement effect. The effects of photocatalyst dosage, initial chlortetracycline (CTC) concentration, solution pH, temperature and coexisting ions on the photocatalytic performance of SSM were systemically investigated. The results indicated that SSM could efficiently degrade CTC in water and swine urine under sunlight, and exhibited high stability against coexistence of urea, Cl- and SO42-. Moreover, SSM showed good reusability in regeneration studies. This work provides a novel method for degrading CTC with potential application prospect.

Electromembrane extraction of clenbuterol from swine urine for monitoring illegal use in livestock.

The illegal use of clenbuterol seriously endangers food safety and human health. Accurate monitoring of the illegal use of clenbuterol in livestock can efficiently prevent the clenbuterol residue pork products from entering the consumer market. Thus, in this study, a simple, rapid, and sensitive method for the determination of clenbuterol in swine urine was developed using electromembrane extraction combined with liquid chromatography-tandem mass spectrometry. It should be noted that the electromembrane extraction method presented many advantages of simple operation, fast mass transfer rate, good sample clean-up capability, and less organic solvent consumption. The effect of important factors on the extraction efficiency of clenbuterol was investigated. Under the optimal conditions, good linearity was achieved for clenbuterol over the range of 1-1000ng/ml (linear correlation [R2 ] =0.9996). The recoveries of clenbuterol in swine urine at three spiked levels ranged from 83.7% to 110.0% with relative standard deviation values lower than 9.7% (n=4). The limits of detection and quantification for clenbuterol were 0.07 and 0.25ng/ml, respectively. These results suggested that the proposed method has great potential for the extraction and determination of trace analyte in a complex sample matrix for monitoring illegal use in livestock.

A highly salt-tolerant monoclonal antibody-based enzyme-linked immunosorbent assay for the rapid detection of phenylethanolamine A in urine

ABSTRACT Phenylethanolamine A (PEAA), as a typical β2-adrenoceptor agonist (β-AA), was widely illegally used in feed to improve the lean meat ratio. The detection performance of immunoassay, which is one of the effective methods to monitor PEAA residues in animal urine, has been hindered by high concentration of salt. Herein, we produced one highly salt-tolerant monoclonal antibody (mAb) 3E2 by hybridoma technology. Homologous modelling and molecular docking were used to analyse the antibody salt tolerance mechanism. Results show that the tight hydrophobic binding cavity is the key to high tolerance. Then the mAb 3E2 was used for specific detecting PEAA by enzyme-linked immunosorbent assay (ELISA) with the IC50 value of 0.36 ng mL−1and the LOD value of 0.065 µg L−1. Benefiting from the high salt tolerance of antibodies, swine urine and sheep urine spiked with PEAA can be detected directly by ELISA, and the acceptable recovery rates of 80.1–108.8% were obtained.

Sensitive and simultaneous detection of ractopamine and salbutamol using multiplex lateral flow immunoassay based on polyethyleneimine-mediated SiO2@QDs nanocomposites: Comparison and application

The abuse of illegal additives poses a severe threat to human health. As such, it is of great significance to develop a simple, rapid and high-throughput analysis method for ensuring food safety from source to terminal. Herein, we proposed a multiplex fluorescent lateral flow immunoassay (LFIA) using the nanoassembly of silicon dioxide (SiO2) and quantum dots (QDs) as the advanced signal probe that can simultaneously detect ractopamine (RAC) and salbutamol (SAL) in swine urine and pork samples, and compared with other four conventional labels. The core–shell SiO2@QDs nanocomposites with strong luminescence, high stability, and abundant surface carboxyl groups were conjugated with antibodies to form high-performance SiO2@QDs immunoprobes, which improve the sensitivity and reliability of the LFIA. The developed SiO2@QDs-based LFIA achieved simultaneous detection of RAC and SAL in one strip within 13 min, with the limit of detection at 0.007 ng/mL and 0.032 ng/mL, respectively. The sensitivity of SiO2@QDs was superior to gold nanoparticles (AuNPs) and fluorescent microspheres (FMs), and exhibited comparative sensitivity with time-resolved microspheres (TRFMs), while overcoming the shortcomings of QDs that tend to aggregate. The recoveries in spiked swine urine and pork samples ranged from 73.7 to 111.0% with relative standard deviations between 4.7% and 15.5%. Good correlations were observed between the SiO2@QDs-based LFIA and commercial enzyme-linked immunosorbent assay for RAC (R2 = 0.936) and SAL (R2 = 0.979) detection. Briefly, the proposed method could be a promising screening on-site tool for convenient, rapid and sensitive detection of multiple illegal additives residues from the source to the terminal in food safety.

Ultrasensitive Magnetic Assisted Lateral Flow Immunoassay Based on Chiral Monoclonal Antibody against R-(-)-Salbutamol of Broad-Specificity for 38 β-Agonists Detection in Swine Urine and Pork.

Screening for ″zero tolerance″ β-agonists requires broad-specificity and sensitivity methods. Herein, R-(-)-salbutamol (SAL) is chirally separated and designed as a hapten, and a monoclonal antibody (mAb) was first prepared with an IC50 of 0.27 ng/mL, which can recognize 38 β-agonists simultaneously. The broad-specificity of chiral mAb was explored by molecular simulation technology. Magnetic nanoparticles (MNPs) were then synthesized and applied as a signal tracer to develop a lateral flow immunoassay (LFIA). The limits of detection of MNPs-LFIA for SAL in swine urine and pork were 0.05 and 0.09 μg/kg, which was (2-125)-fold lower than that of the reported LFIAs. The recoveries were between 95.8 and 116.7%, with the coefficient of variation from 2.7 to 15.4%. Parallel analysis of 44 samples by commercial ELISA kits confirmed the reliability. Therefore, our work not only provides a broad-specificity and ultrasensitive method for β-agonists but also suggests that chirality is the new general theory that guided the rational hapten design.

In vitro induced pluripotency from urine-derived cells in porcine.

BACKGROUNDThe generation of induced pluripotent stem cells (iPSC) has been a game-changer in translational and regenerative medicine; however, their large-scale applicability is still hampered by the scarcity of accessible, safe, and reproducible protocols. The porcine model is a large biomedical model that enables translational applications, including gene editing, long term in vivo and offspring analysis; therefore, suitable for both medicine and animal production.AIMTo reprogramme in vitro into pluripotency, and herein urine-derived cells (UDCs) were isolated from porcine urine.METHODSThe UDCs were reprogrammed in vitro using human or murine octamer-binding transcription factor 4 (OCT4), SRY-box2 (SOX2), Kruppel-like factor 4 (KLF4), and C-MYC, and cultured with basic fibroblast growth factor (bFGF) supplementation. To characterize the putative porcine iPSCs three clonal lineages were submitted to immunocytochemistry for alkaline phosphatase (AP), OCT4, SOX2, NANOG, TRA1 81 and SSEA 1 detection. Endogenous transcripts related to the pluripotency (OCT4, SOX2 and NANOG) were analyzed via reverse transcription quantitative real-time polymerase chain reaction in different time points during the culture, and all three lineages formed embryoid bodies (EBs) when cultured in suspension without bFGF supplementation.RESULTSThe UDCs were isolated from swine urine samples and when at passage 2 submitted to in vitro reprogramming. Colonies of putative iPSCs were obtained only from UDCs transduced with the murine factors (mOSKM), but not from human factors (hOSKM). Three clonal lineages were isolated and further cultured for at least 28 passages, all the lineages were positive for AP detection, the OCT4, SOX2, NANOG markers, albeit the immunocytochemical analysis also revealed heterogeneous phenotypic profiles among lineages and passages for NANOG and SSEA1, similar results were observed in the abundance of the endogenous transcripts related to pluripotent state. All the clonal lineages when cultured in suspension without bFGF were able to form EBs expressing ectoderm and mesoderm layers transcripts.CONCLUSIONFor the first time UDCs were isolated in the swine model and reprogrammed into a pluripotent-like state, enabling new numerous applications in both human or veterinary regenerative medicine.

An ultrasensitive colloidal gold immunosensor to simultaneously detect 12 beta (2)-adrenergic agonists

In this study, we first prepared a selective monoclonal antibody against 12 beta (2)-adrenergic agonists (Salbutamol, Clenbuterol, Brombuterol, Clenpenterol, Mabuterol, Carbuterol, Cimbuterol, Mapenterol, Pirbuterol, Terbutaline, Cimaterol, and Clenproperol). Then three haptens were designed and derived, among which, haptenS3 used the amino group of the salbutamol analog to derive a carboxyl group containing a spacer, which is unique to this study. The half-maximal inhibitory concentration (IC50) values were 0.35 ng/mL (Salbutamol), 0.42 ng/mL (Clenbuterol), 0.78 ng/mL (Brombuterol), 0.88 ng/mL (Clenpenterol), 1.34 ng/mL (Mabuterol), 1.38 ng/mL (Carbuterol), 1.71 ng/mL (Cimbuterol), 2.24 ng/mL (Mapenterol), 2.25 ng/mL (Pirbuterol), 2.27 ng/mL (Terbutaline), 3.49 ng/mL (Cimaterol), and 4.89 ng/mL (Clenproperol). We further developed a monoclonal antibody-based colloidal gold immunochromatographic test strip for screening and detecting 12 beta (2)-adrenergic agonists in swine urine and lamb samples. The immunochromatographic method developed in this study is a suitable tool for the on-site rapid detection and screening of beta (2)-adrenergic agonists in swine urine and lamb samples.

Rapid detection of sulfonamide antibiotics residues in swine urine by surface-enhanced Raman spectroscopy

Surface enhanced Raman spectroscopy (SERS) combined with rapid pretreatment technique was used to determine sulfonamide antibiotics (sulfadiazine and sulfathiazole) residue in swine urine. Au nanoparticles (AuNPs) were synthesized as Raman enhance substrate and the extraction of swine urine was purified with primary secondary amine (PSA), octadecyl silane (C18) and graphitized carbon (GCB) to eliminate the interference of the matrix and different dosages of adsorbents (PSA, C18, GCB) were investigated. The results showed that the treatment with C18 of 150 mg, GCB of 200 mg and PSA of 200 mg were an excellent approach for rapidly detecting sulfonamide antibiotics residue in swine urine. Combined with density functional theory calculation (DFT), Raman characteristic peaks of 819, 1102, 1173, 1588 cm−1 and 825, 1127 cm−1 were selected for qualitative and quantitative assessment of sulfadiazine and sulfathiazole in swine urine, respectively. Based on raman characteristic peak of 819 cm−1, a good linear relationship between sulfadiazine concentration and Raman intensity was developed with R2 = 0.9912, and based on raman characteristic peak of 825 cm−1, a good linear relationship between sulfathiazole concentration and Raman intensity was developed with R2 = 0.9941. And recoveries for five unknown concentration samples predicted were 98.47 ∼ 105.18% with relative standard deviation (RSD) of 1.53% ∼ 5.18%. This study demonstrated that SERS coupled with a quick, easy, cheap, effective, rugged, and safe (QuEChERS) method could be employed to rapidly examine the sulfonamide antibiotics residue in swine urine towards its quality and safety monitoring.

Twelve natural estrogens in urines of swine and cattle: Concentration profiles and importance of eight less-studied

Although four major natural estrogens (i.e., estrone (E1), 17β-estradiol (E2), estriol (E3) and 17α-estradiol (αE2)) have been commonly found in livestock urine, this study reports the occurrence of eight other less-studied natural estrogens in urine of swine and cattle, i.e. 2-hydroxyestone (2OHE1), 4-hydroxyestrone (4OHE1), 2-hydroxyestradiol (2OHE2), 4-hydroxyestradiol (4OHE2), 16-epiestriol (16epiE3), 16α-hydroxyestrone (16αE1), 16-ketoestradiol (16ketoE2), and 17epiestriol (17epiE3). Results showed that each estrogen was found in at least one urine sample, and 6 of 8 the less-studied estrogens were present at frequencies of ≥90% in boars, ≥70% in sows, and ≥50% in dairy cattle. Five of eight the less-studied estrogens were present at frequencies of ≥33.3% in four beef cattle and one bull. On a concentration basis, the 8 less-studied natural estrogens represented 73.2%, 85.2%, 39.9%, 47.7%, 26.9%, 56.0% and 44.1% of total concentrations of the twelve natural estrogens when combining data from all animals. Similar results were observed based on estrogen equivalence, which indicated these newly detected eight less-studied natural estrogens were not negligible. This work is the first to figure out the importance of these less-studied natural estrogens in livestock urine, and their potential environmental risks associated with discharge of livestock wastewater should be urgently assessed in a holistic manner.

Influence of Selective Agents (EMJH-STAFF), Sample Filtration and pH on Leptospira interrogans Serovar Icterohaemorrhagiae Cultivation and Isolation from Swine Urine.

Leptospira spp. cause the zoonotic disease leptospirosis, which occurs in numerous mammalians worldwide. Isolation is still important for serotyping and genotyping of Leptospira, which in turn is essential for epidemiological surveillance of leptospirosis and the development of diagnostic tests and vaccines. However, isolation of Leptospira from clinical specimens is inherently insensitive. This study was conducted to examine the influence of selective agents, sample filtration, sample pH and the use of phosphate buffered saline (PBS) buffer for sample storage to improve the success of cultivation and isolation of Leptospira interrogans serovar Icterohaemorrhagiae from swine urine. EMJH (Ellinghausen McCullough, Johnson and Harris) medium including the selective agents sulfamethoxazole, trimethoprim, amphotericin, fosfomycin and 5-fluorouracil (STAFF) increased the success of Leptospira isolation from spiked swine urine samples. Sample filtration yielded only negative results. Isolation in EMJH-STAFF was successful from swine urine with a density as low as 104 Leptospira/mL, and urine with pH ≤ 7 impaired the cultivation rate. Cultivation and isolation were not improved by the addition of PBS to spiked urine samples prior to storage for 24 h at 4 °C. The results of the study demonstrate that cultivation and isolation of leptospires from swine urine can be improved by enhanced methods.

Simultaneous Determination of Ten Banned Substances in Pig Urine by Liquid Chromatography-Tandem Mass Spectrometry

A simple, sensitive and reliable method was developed for simultaneous determination of ten banned drugs residues including zeranols (ZALs), chloroamphenicol, pentachlorophenol, etc. in swine urine using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The urine samples were pretreated using lyophilization and QuEChERS procedures, respectively. Acetonitrile and ammonium acetate (5 mmol/L) were chosen as mobile phases. Target compounds were separated well in ZorbaxSB-C18 by following the optimized gradient elution program and determined by LC-MS/MS in negative electrospray ionization mode. The linearity of the matrix-matched standard curve of ten analytes in two methods was good in the range of the experimental concentration with correlation coefficients more than 0.99. The recoveries of ten drugs were in the range of 80.7%-107.7% and 73.5%-103.3% at the spiked levels of 5, 10 and 20 μg/L by lyophilization and QuEChERS methods, respectively. The coefficients of variation were less than 15%. The limits of detection (LOD) and the limits of quantification (LOQ) from lyophilization and QuEChERS method were 0.1 to 2.0 μg/L and 0.2 to 5.0 μg/L, respectively.

Effects of 105 traditional Chinese medicines on the detection of β-agonists in medicine extracts and swine urine based on colloidal gold immunochromatographic assay

Colloidal gold immunochromatographic assay (CGIA) is commonly used for the on-site detection of β-agonists that are sometimes used illegally as feed additives in swine diets. However, few studies have evaluated the causes of false-positive results that sometimes occur when applying CGIA in agricultural settings. In this study, we investigated if this false-positive phenomenon is related to the addition of certain traditional Chinese medicines (TCMs) to swine feed. We established and verified an extraction method for TCMs, and then applied CGIA to detect β-agonists in the extracts of 105 TCMs and in the urine of swine dosed with TCMs, respectively. Liquid chromatography-tandem mass spectrometry was used to validate the results of the urine samples tested positive for β-agonists using CGIA. The results were also verified using TCMs and colloidal gold test strips produced by different manufacturers. The extracts of Citri Reticulatae Pericarpium Viride, Citri Reticulatae Pericarpium, Magnoliae Officinalis Cortex, Chaenomelis Fructus, and Rhodiolae Crenulatae Radix Et Rhizoma were tested positive for β-agonists. Meanwhile, the addition of Citri Reticulatae Pericarpium Viride and Citri Reticulatae Pericarpium to swine feed resulted in false-positive results for β-agonists in swine urine. The results provide a new way to explain false-positive CGIA results and provide valuable information for livestock feeding programs.

Fabrication of Fe3O4/ZIF-8 nanocomposite for simultaneous removal of copper and arsenic from water/soil/swine urine

In this study, a magnetic nanocomposite (denoted as FZ) was fabricated using Fe3O4and zeolitic imidazolate framework-8 (ZIF-8), based on a coprecipitation method. FZ could efficiently remove Cu2+(Cu(II)) and AsO2− (As(III)) ions simultaneously from water, soil, and swine urine samples through hydrogen bonding and electrostatic interactions. The Cu(II) and As(III) removal efficiencies of the optimal FZ sample increased gradually with time and reached 99.1% and 98.4%, respectively, in 180 min. The maximum adsorption capacities of FZ4 for Cu(II) and As(III) were determined to be 33.48 mg/g and 21.12 mg/g, respectively. Additionally, the FZ with a high saturation magnetization (49.8 emu/g) was easily recovered from aqueous solutions and soil samples. Furthermore, zebrafish experiments indicated that FZ possessed a high biosafety. Thus, this study introduces a promising method for treating water, soil, and swine urine samples contaminated with Cu(II) and As(III), and verifies that FZ is suitable for practical application.