Effects of Maternal Factors and Postpartum Environment on Early Colonization of Intestinal Microbiota in Piglets.

Intestinal microbiota significantly influences the intake, storage, and utilization of body nutrients, as well as animal growth and development. The establishment of microbiota is affected by many factors, such as delivery and feeding modes, antibiotics, disease, and the surrounding environment. In this study, we selected Chinese indigenous Mashen and Jinfen White pigs as the study subjects. To explore the source and factors affecting the piglet intestinal microbiota, 16S rRNA gene sequencing was performed to analyze the microbial composition of the feces, saliva, vaginal secretions, and colostrum of parturient sows, feces and saliva of newborn piglets, and surrounding environment samples. The results showed that the microbiota of the saliva of sows and piglets is structurally similar to that of the environment and is dominated by the phylum Proteobacteria, including Acinetobacter, Actinomyces, and Pseudomonas. The core genus in the vaginal secretions and colostrum of sows was Pseudomonas. Among the fecal samples, the core bacterial genera in sows before and after delivery were Clostridium sensu_stricto_1 and Christensenellaceae_R-7_group, while in piglets at 1 d of age, Pseudomonas and Escherichia-Shigella were most abundant. These results indicate that microbiota in feces, colostrum, and vaginal secretions of sows more easily colonized piglet intestines through a symbiotic effect. The environmental and salivary microbiota could also affect the early colonization and succession of the intestinal microbiota of piglets to some extent. This study provides a theoretical basis for sow delivery protection and early nursing of piglets and background for the research and development of microbial agents to improve piglet intestinal health.

Pb4B6O13: A Polar Lead Oxyborate with Uncommon ∞(B6O12)6- Layers Exhibiting a Large Second Harmonic Generation Response.

A new lead oxyborate, Pb4B6O13, has been successfully synthesized by introducing stereochemically active Pb2+ cations and distorted OPb4 tetrahedra into asymmetric borates. Pb4B6O13 exhibits an unprecedented two-dimensional ∞(B6O12)6- layer structure with a large second harmonic generation (SHG) response that is 3 times that of KH2PO4. In addition, theoretical work, including dipole moment calculations, electronic structure, and SHG coefficients combined with SHG density analysis, is reported. The results suggest that the enhanced SHG of Pb4B6O13 is attributed to the synergy effect of three functional units.

Trace residue analysis of dicyandiamide, cyromazine, and melamine in animal tissue foods by ultra-performance liquid chromatography.

An effective sample preparation procedure using an accelerated solvent extraction (ASE) procedure, followed by cleaning with melamine molecularly imprinted polymers solid-phase extraction (MISPE) was developed. A novel and highly sensitive ASE-MISPE-ultra-performance liquid chromatography (UPLC) method was developed for effective separation and simultaneous determination of dicyandiamide (DCD), cyromazine (CYR), and melamine (MEL) in complex animal tissue foods. Under optimized conditions, good linearity was achieved with a correlation coefficient (r) of 0.9999 in the range of at least two orders of magnitude. The limit of quantification of the method was 1.7 µg/kg, 5.0 µg/kg, and 3.2 µg/kg for DCD, MEL, and CYR, which was three orders of magnitude smaller than the maximum residue limits (MRLs). The intra- and inter-day precisions (in terms of the relative standard deviation, RSD) of the three analytes were in the range of 1.7-3.1% and 3.1-6.3%, respectively. The average recoveries of analytes from blank chicken, beef, mutton, pork, and pig liver samples spiked with the three levels varied from 91.2% to 107% with RSD of 1.7-8.3% for DCD, 89.0-104% with RSD of 2.1-6.1% for CYR, and 94.8-105% with RSD of 1.1-6.6% for MEL. The proposed method has the characteristics of speed, sensitivity, and accuracy, and can be used for the routine determination of DCD, CYR, and MEL at the µg/kg level in complex animal tissue foods.

Synthesis and evaluation of dummy molecularly imprinted microspheres for the specific solid-phase extraction of six anthraquinones from slimming tea.

Dummy molecularly imprinted microspheres with danthron as template were synthesized and their performance was evaluated. Accelerated solvent extraction can rapidly and effectively remove template molecules from the microspheres. The microspheres were applied as a specific sorbent for solid-phase extraction of six anthraquinones from slimming tea, showing excellent affinity and high selectivity to danthron and the target analytes. The molecular recognition mechanisms were discussed by the experimental validation with IR spectroscopy. The sample was treated using accelerated solvent extraction followed by dummy molecularly imprinted microspheres solid-phase extraction. Under the optimized ultra high performance liquid chromatographic conditions, the six target analytes can be baseline separated in 8 min, and good linearity was obtained in a range of 0.1-40 µg/mL with the correlation coefficient (r(2)) of ≥0.9998. The method limit of quantification was in a range of 1-2 mg/kg, it can ensure analysis of anthraquinones at mg/kg level. The intra- and interday precision (RSD, n = 6) for the analysis of the six analytes in a slimming tea was less than 4.5 and 5.4%, respectively. The developed method can be applied for the selective extraction, effective separation, and rapid determination of six anthraquinones in slimming tea.

Highly sensitive determination of cyromazine, melamine, and their metabolites in milk by molecularly imprinted solid-phase extraction combined with ultra-performance liquid chromatography.

A novel molecularly imprinted solid-phase extraction-ultra-performance liquid chromatography (MISPE-UPLC) method for effective separation and simultaneous determination of cyromazine, melamine, and their metabolites (ammeline and ammelide) in milk samples was developed. Molecularly imprinted polymers (MIP) were synthesized in an ethanol-water system, with melamine as the template and methacrylic acid as the organic functional monomer. The MIP were applied as a specific sorbent for the selective solid phase extraction of cyromazine, ammelide, melamine and ammeline. The molecular recognition mechanism was investigated by molecular simulation and the experiment was validate by using Fourier transform infrared spectroscopy and (1)H nuclear magnetic resonance spectroscopy. A new mechanism based on the formation of both an amido group and hydrogen bonds was developed. A binding study demonstrated that the MIP showed excellent affinity to and high selectivity for melamine and related compounds. Under optimized conditions, we achieved good linearity of the calibration curves with correlation coefficients >0.999. Low limits of quantification (LOQ) for the method were determined to be 1.25, 1.25, 2.59, and 6.42 µg/kg for cyromazine, ammelide, melamine, and ammeline, respectively, which were 3 orders of magnitude smaller than the maximum residue limit (MRL). The high sensitivity of this method allows detection at the microgram per kilogram level. The proposed MISPE-UPLC method is a highly selective and sensitive method for determination of cyromazine, melamine, and their metabolites (ammeline and ammelide) for use in the control and quality assurance of milk.

A sensitive and validated HPLC method for the determination of cyromazine and melamine in herbal and edible plants using accelerated solvent extraction and cleanup with SPE.

A highly sensitive method was developed for the determination of the residues of cyromazine (CYR) and its metabolite, melamine (MEL), in herbal and edible plant samples by using reversed phase high-performance liquid chromatography-diode-array detection (RP-HPLC-DAD) with accelerated solvent extraction and solid phase extraction cleanup. The conditions of separation and detection were investigated and optimized. A Waters C18 column (250 × 4.6 mm i.d., 5 µm) was used for the RP-HPLC, with a mobile phase composed of 0.1% trifluoroacetic acid solution and methanol (85:15, v/v, pH 2.6). Under the optimized conditions, good linearity was achieved with a correlation coefficient of 0.9998. The limits of quantification of the method were 2.15 µg/kg for CYR and 2.51 µg/kg for MEL, which are maximum residue limits as low as three orders of magnitude. The recovery values at three spiked concentrations were in the range of 96.2-107.1% with relative standard deviations (RSDs) of 1.1-5.7% for CYR, and 92.7-104.9% with RSDs of 1.7-6.1% for MEL. The proposed method allows detection at levels as low as µg/kg levels for CYR and MEL. The method was validated by liquid chromatography-tandem mass spectrometry, and can be used for the routine determination of CYR and MEL in herbal and edible plant samples with the characteristics of speed, high sensitivity and accuracy, and low consumption of reagents.

Simultaneous determination of the combined drugs of ceftriaxone sodium, metronidazole, and levofloxacin in human urine by high-performance liquid chromatography.

AIM: To develop a new high-performance liquid chromatography (HPLC) method for simultaneous determination of the combined drugs (ceftriaxone sodium, metronidazole, and levofloxacin) in human urine. METHODS: Ceftriaxone sodium, metronidazole, and levofloxacin were separated on a Kromasil 100-5 C18 (250 mm × 4.6 mm, 5 µm, AKZO NOBEL, Bohus, Sweden) analytical column, using the mobile phase consisted of 1.5 mM KH(2) PO(4) (pH 4.5) with 0.0125% triethylamine-methnol (70:30, v/v). Ceftriaxone sodium, metronidazole, and levofloxacin were detected by a photodiode-array detector at 247, 320, 292 nm, respectively. RESULTS: Under optimal conditions, the effective separation of ceftriaxone sodium, metronidazole, and levofloxacin was achieved. A good linearity with the correlation coefficients more than 0.999 was demonstrated. The detection limits of ceftriaxone sodium, metronidazole, and levofloxacin were 0.05, 0.01, and 0.25 µg/ml, respectively, and the average recoveries in human urine were in the range from 97.73 to 100.7% with the average relative standard deviation (RSD) in the range of 2.5% and 3.0%. CONCLUSION: The proposed method was sensitive, accurate, and rapid. This work may provide a reference for clinical rational drug use and methodology for the pharmacokinetics study of the combined drugs.

Application of accelerated solvent extraction in the analysis of organic contaminants, bioactive and nutritional compounds in food and feed.

Accelerated solvent extraction (ASE) has become a popular green extraction technology for different classes of organic contaminants present in numerous kinds of food and feed for food safety. The parameters affecting ASE efficiency and application advancement of ASE in the analysis of organic contaminants, natural toxins compounds as well as bioactive and nutritional compounds in animal origin food, plant origin food and animal feed are reviewed in detail. ASE is a fully automated and reliable extraction technique with many advantages over traditional extraction techniques, so it could be especially useful for routine analyses of pollutants in food and feed.

Effective separation and sensitive determination of cyanuric acid, melamine and cyromazine in environmental water by reversed phase high-performance liquid chromatography.

A new method for the simultaneous determination of cyanuric acid (CA), melamine (MM) and cyromazine (CM) in different water samples was developed by using reversed phase high-performance liquid chromatography diode-array detection (RP-HPLC-DAD). The conditions of HPLC were investigated and optimized. A KROMASIL C18 column (250 x 4.6 mm ID, 5 microm) was used for the RP-HPLC using gradient elution with a mobile phase composed of 0.1 mM KH2PO4-K2HPO4 buffer solution (pH = 7.3) and methanol (75:25, v/v). The conditions for HPLC were investigated and optimized. Under optimal conditions, the linearity was satisfactory in the range of 0.04-10.00 microg/mL with a correlation coefficient of 0.999, and the method limits of detection (LODs) of the proposed method were 0.02 microg/mL for CA and CM, and 0.01 microg/mL for MM. The recoveries were: 96.0-116.0% with relative standard deviations (RSDs) of 0.9-5.7% for CA, 94.3-115.0% with RSDs of 1.5-5.3% for MM, and 91.0-112.0% with RSDs (n = 6) of 1.0-4.9% for CM. The proposed method can permit the detection of CA and CM at levels as low as 0.07 microg/mL and MM at levels as low as 0.03 microg/mL in environmental water samples.

Simultaneous determination of malachite green, enrofloxacin and ciprofloxacin in fish farming water and fish feed by liquid chromatography with solid-phase extraction.

An effective and sensitive method for simultaneous analysis of malachite green (MG), enrofloxacin (ENFLX) and ciprofloxacin (CPFLX) by liquid chromatography-diode array detection with solid-phase extraction (SPE) is developed. The conditions of SPE and LC were investigated and optimised. The effective separation of these compounds was achieved using a ZY1104 C18 column (250 × 4.6 mm, 5 µm) with 20 mM tetrabutyl ammonium bromide (pH 3.0)-acetonitrile as mobile phase and gradient elution. The diode array detection was used at 278 nm for ENFLX and CPFLX and at 613 nm for MG. Under the optimal conditions, the method LOD values of MG, ENFLX and CPFLX were 0.01, 0.07 and 0.10 µg L( -1) for fish farming water samples and 1.5, 10.5 and 15 µg kg( -1) for fish feed samples, respectively. The relative recoveries of the three analytes were achieved to be 76.7-82.3% with the RSDs (n = 5) of 3.2-4.6% for spiked fish farming water samples and 78.8-93.7% with the RSDs (n = 5) of 3.1-4.8% for spiked fish feed samples.