Activity

-hexane sulfonate solution to the superstratum extract with the use of only Oasis HLB for sample treatment. The method described herein has the advantages of easy operation, accuracy, and selectivity, making it feasible for the identification and quantification of STR and DSTR residues in grapes.The presence of 3-chloro-1,2-propanediol fatty acid esters (3-MCPDE) in food and processed materials has recently become a topic of concern because of the toxicity of their metabolites. 3-MCPDE structurally similar to glyceride, which makes it difficult to separate or extract them from oils and fritters. A method based on ultra performance convergence chromatography-tandem mass spectrometry (UPC2-MS/MS) was established for the determination of 15 3-MCPDE in vegetable oils and fritters. Amino-packed columns were used to purify the samples. The analytical conditions were optimized, and the matrix effect was investigated. The sample was treated by column chromatography to remove glyceride and free fatty acids, which induce strong matrix effects. The amino-packed column was eluted with hexane and hexane-ethyl acetate (64, v/v). Every 1 mL of the eluent was analyzed using a UPC2 and ACQUITY QDa detector. Elution curves were drawn based on the testing data and used to determine the collection volume. The collectiontion of monoesters, for example, via derivatization.Bisphenols are important industrial raw materials that are widely used to produce plastic bottles (feeding bottles), infant cups, and food and beverage (milk powder) cans. Because of the estrogen-like effect of bisphenols, even low-dose intake of these compounds by trace migration affects normal hormone levels in the human body. Therefore, it is imperative to develop a rapid, accurate, and highly sensitive method for the determination of bisphenols in serum. In this study, methyl tert-butyl ether (MTBE) was used as the extraction solvent, and the liquid-liquid extraction pretreatment method was used for sample processing. A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was established for the simultaneous determination of bisphenol A (BPA), bisphenol B (BPB), bisphenol F (BPF), and bisphenol S (BPS) at trace levels in infant serum. The important parameters affecting the extraction efficiency, such as the extraction solvent, extraction time, and extraction solvent volume fmples. BPA was detected in most serum samples, and the detection rates in the serum of boys and girls were 90.67% and 89.33%, respectively. The detection rates of BPF in the serum of boys and girls were 6.67% and 1.33%, respectively; the corresponding values for BPS were 5.33% and 16.00%. BPB was not detected. The proposed method has the advantages of simple operation, good recovery, and high precision, and it is suitable for the simultaneous determination of the four bisphenol environmental hormones in infant serum.Organophosphate ester (OPE)-based flame retardants and plasticizers are widely utilized in various industrial products, and are being increasingly used as substitutes for gradually phased brominated flame retardants (BFRs). According to the different types of substituents used, OPEs are mainly divided into alkyls, halogenated compounds, and aromatics, which have widely varying physicochemical properties. OPEs can induce neurotoxicity, carcinogenicity, and damage in endocrine and reproductive systems in humans. Examples of halogenated OPE are tris(2-chloroisopropyl) phosphate (TCIPP) and tris(1,3-dichloropropyl) phosphate (TDCIPP), which are suspected to be carcinogenic. OPEs have emerged as pollutants in environmental and food matrices as a result of volatilization and abrasion processes. Due to its low content in the food matrix and serious background interference, there is a lack of reliable and sensitive analytical methods. Recently, there has been a focus on the detection of OPE flame retardants in food. equired. The screening and identification of unknown metabolites of OPEs and related analytical methods based on high resolution mass spectrometry could also be studied for precursor OPEs in foodstuffs in the future.Brazilein is among the main chemical constituents of Caesalpinia sappan. ABT-199 cell line It has diverse pharmacological activities. Modern pharmacological studies have shown that the compound has antitumor, anti-inflammatory, antibacterial, antioxidant, immunomodulatory, and other pharmacological activities. Brazilein is often used as a stain in various industries. The separation of brazilein by traditional column chromatography will not only result in contamination of the chromatographic column materials, but also lead to loss of the active ingredient. Countercurrent chromatography is an advanced liquid-liquid chromatographic separation technique. It has been widely used for natural product separation and isolation as it offers several advantages, such as low solvent consumption, a highly selective solvent system, and high recoveries. Typical countercurrent chromatography techniques include centrifugal partition chromatography (CPC), high-speed countercurrent chromatography (HSCCC), and high performance countercurrent chromration mode of HPCCC, the reversed-phase liquid chromatography mode with the apparatus rotated at 1600 r/min, a flow rate of 10 mL/min, separation temperature of 25℃, and detection wavelength of 285 nm. Their structures were determined by spectroscopic and spectrometric analyses. Brazilein stained the solid packing material in the column and was difficult to elute. The results showed that the use of HPCCC for the separation of brazilein can not only prevent the loss of target active ingredients in Caesalpinia sappan, but also shorten the separation and purification times and improve the operating efficiency. Therefore, HPCCC can be used for the separation and preparation of other pigment compounds in Caesalpinia sappan and other dye plants.In this study, core-shell mesoporous silica-carbon composite microspheres (Sil@MC) were prepared by one-step coating of the phenol formaldehyde polymer (PF) on SiO2 surface and by carbonizing the PF polymer under nitrogen atmosphere. The morphology observation of the Sil@MC stationary phase showed that it had good monodispersity. Surface area (302 m2/g), mean pore diameter (9.5 nm), and pore volume (0.63 cm3/g) of Sil@MC materials were also measured by pore structure analysis. The results showed that the Sil@MC was successfully immobilized on the silica particles via copolymerization and carbonization. As a stationary phase of HPLC, the Sil@MC column was filled by a slurry method. The Sil@MC materials formed after calcination of SiO2 coated with phenolic resin could be used for the separation of four polar sugar compounds (D-(+)-glucosamine hydrochloride, glucose, D-(+)-trehalose dihydrat and raffinose) with the mobile phase of acetonitrile-water (containing 0.1% (v/v) formic acid). However, the material formed by calcinating SiO2 without coating phenolic resin could not separate these polar sugar compounds by HPLC-MS.