[Simultaneous determination of 37 mycotoxins in grain and animal feed by impurity adsorption purification coupled with ultra-performance liquid chromatography-tandem mass spectrometry].

A rapid method based on ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the simultaneous determination of 37 mycotoxins having various physicochemical properties in grain and animal feed samples. The 37 analytes were extracted from ground samples with acetonitrile-water-formic acid (84:15.9:0.

Determination of 2,3,7,8-tetrachlorodibenzo-p-dioxin based on SERS substrates composited of Au nanoparticles supported on twice-oxidized graphene oxide.

A surface-enhanced Raman spectroscopy (SERS) substrate consisting of Au nanoparticles supported on twice-oxidized graphene oxide (ro-GO) for the determination of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was prepared. The Raman shift at △v = 779, 993, and 1203 cm was collected on the excitation condition of λ = 785 nm for the qualitative identification of 2,3,7,8-TCDD in milk. The peak at △v = 1203 cm was selected as the characteristic peak for quantitation.

Metal-Organic Frameworks for Food Safety.

Food safety is a prevalent concern around the world. As such, detection, removal, and control of risks and hazardous substances present from harvest to consumption will always be necessary. Metal-organic frameworks (MOFs), a class of functional materials, possess unique physical and chemical properties, demonstrating promise in food safety applications.

Rapid and sensitive detection of acrylamide in fried food using dispersive solid-phase extraction combined with surface-enhanced Raman spectroscopy.

A rapid, reliable, and quantitative method to determine acrylamide content in fried food based on surface-enhanced Raman spectroscopy (SERS) by re-oxidized graphene oxide/Au nanoparticle composites and dispersive solid-phase extraction has been proposed. The peak at △v = 1478 cm was selected as the characteristic peak of acrylamide for quantitation. Sufficient linearity was obtained in the concentration range of 5-100 μg·kg (R = 0.

Phosphoproteome Analysis Reveals the Molecular Mechanisms Underlying Deoxynivalenol-Induced Intestinal Toxicity in IPEC-J2 Cells.

Deoxynivalenol (DON) is a widespread trichothecene mycotoxin that commonly contaminates cereal crops and has various toxic effects in animals and humans. DON primarily targets the gastrointestinal tract, the first barrier against ingested food contaminants. In this study, an isobaric tag for relative and absolute quantitation (iTRAQ)-based phosphoproteomic approach was employed to elucidate the molecular mechanisms underlying DON-mediated intestinal toxicity in porcine epithelial cells (IPEC-J2) exposed to 20 μM DON for 60 min.

Highly Sensitive Detection of Clenbuterol in Animal Urine Using Immunomagnetic Bead Treatment and Surface-Enhanced Raman Spectroscopy.

Combining surface-enhanced Raman spectroscopy (SERS) of aggregated graphene oxide/gold nanoparticle hybrids with immunomagnetic bead sample preparation method, a highly sensitive strategy to determine the clenbuterol content in animal urine was developed. Based on a linear calibration curve of the SERS characteristic peak intensity of clenbuterol at Δv = 1474 cm(-1) versus the spiked clenbuterol concentration in the range of 0.5-20 ng·mL(-1), the quantity of clenbuterol in real animal urine samples can be determined and matches well with those determined by LC-MS/MS, while the detection time is significantly reduced to 15 min/sample.

Highly Sensitive Detection of Melamine Using a One-Step Sample Treatment Combined with a Portable Ag Nanostructure Array SERS Sensor.

There is an urgent need for rapid and reliable methods able to detect melamine in animal feed. In this study, a quick, simple, and sensitive method for the determination of melamine content in animal feed was developed using surface-enhanced Raman spectroscopy on fabricated Ag nanorod (AgNR) array substrates with a one-step sample extraction procedure. The AgNR array substrates washed by HNO3 solvent (10-7 M) and methanol and showed the good stability within 6 months.

Development of a Efficient and Sensitive Dispersive Liquid-Liquid Microextraction Technique for Extraction and Preconcentration of 10 β2-Agonists in Animal Urine.

Dispersive liquid-liquid microextraction (DLLME) coupled with ultra-performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) was developed for the extraction and determination of 10 β2-agonists in animal urine. Some experimental parameters, such as the type and volume of the extraction solvent, the concentration of the dispersant, the salt concentration, the pH value of the sample solution, the extraction time and the speed of centrifugation, were investigated and optimized. Under the optimized conditions, a good enrichment factors (4.

Detection of melamine in feed using liquid-liquid extraction treatment combined with surface-enhanced Raman scattering spectroscopy.

A rapid, selective, and sensitive method to determine the melamine content in animal feeds was developed using surface-enhanced Raman scattering spectroscopy on aggregated 55 nm Au nanoparticles with liquid-liquid extraction sample preparation. Butyl alcohol was used as the initial extraction solvent, and liquid-liquid extraction was performed twice using HCl (pH 3-4) and 6:1 (v/v) n-butyl alcohol/ethyl acetate. The intensity of the matrix-based peak at 731 cm⁻¹ was set at 100 as a basis for the feeds, and the peak at 707 cm-1 was the characteristic peak of melamine used in the calculations.

Simultaneous identification and quantification of 20 β-receptor agonists in feed using gas chromatography-tandem mass spectrometry.

"Lean meat powder" is a class of toxic chemicals that have structures similar to that of β-adrenergic receptor agonists. At least 16 chemicals from this class have been specifically banned by the 176(th) bulletin of the Chinese Department of Agriculture on breeding animals, and methods for monitoring the illicit use of β-agonists in animal feed are required. Herein, a method to quantify 20 β-agonists in feed, via analyte derivatization followed by gas chromatography-tandem mass spectrometry, has been developed.

[Rapid determination of melamine in pet food by surface enhanced Raman spectroscopy in combination with Ag nanoparticles].

The rapid qualitative and quantitative analysis of melamine in pet food was realized by surface-enhanced Raman spectroscopy in combination with Ag nanoparticle. In the present study, the 709 and 1 542 cm(-1) Raman shift was chosen as qualitative basis. The quantitative calculation of the concentration range between 1.

Variable levels of 37-kDa/67-kDa laminin receptor (RPSA) mRNA in ovine tissues: potential contribution to the regulatory processes of PrPSc propagation?

The 37-kDa laminin receptor precursor/67-kDa laminin receptor (LRP/LR, also known as ribosomal protein SA, RPSA) has been reported to be involved in cancer development and prion internalization. Previous studies have shown that the LRP/LR is expressed in a wide variety of tissues. In particular, expression of LRP/LR mRNA may be closely related to the degree of PrP(Sc) propagation.

Microvalve-actuated precise control of individual droplets in microfluidic devices.

Integrated microvalves have been used to precisely and flexibly control the generation, size, composition of individual droplets and fusion of different droplets in microfluidic devices.

[Study on determination of rare earth La and Ce in feed by using ICP-MS].

An advanced method for the determination of rare earth La and Ce in animal feed by using of inductively coupled plasma mass spectrometry was studied. The operation parameters for ICP-MS was optimized, the effect of pre-mix feed matrix and formular feed matrix for La and Ce was studied by the conventional method and stepwise dilution method, and the suppression of signal intensity of La and Ce by nitric acid was examined. Under the optimum condition, the limit of determination for La and Ce were 2.

[Study on the method of using ICP-MS to determine microelements in the animal feed].

The method for the determination of microelements such as Cu, Zn, Fe, Mn, Cr, Cd, Pb, As and Se in the animal feed by inductively coupled plasma-mass spectrometry was developed. The operation parameters, spectrum interference, matrix effect and memorial effect were studied in detail. Under optimal condition, the detection limits of these nine elements were from 2.