In this study, a diethoxy-pillar[5] arene (EtP5) doped deep eutectic solvent (DES) monolithic column was prepared using diethylene glycol dimethacrylate (EGDMA) as the crosslinker for pipette tip micro-solid phase extraction (PT-μSPE) of phthalate esters (PAEs). The column was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, nitrogen adsorption-desorption measurement, thermogravimetric analysis, and contact angle goniometry. The saturated adsorption capacities of the EtP5 doped poly(DES- co -EGDMA) monolithic column for dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), dicyclohexyl phthalate (DCHP), diethylhexyl phthalate (DEHP), dioctyl phthalate (DOP), and dinonyl phthalate (DNP) were 15.3, 22.7, 41.2, 43.0, 37.6, 36.1, 35.6, and 32.8 mg·g −1 , respectively. The EtP5 doped poly(DES- co -EGDMA) monolithic column has a service life of at least 80 cycles and exhibits superior adsorption selectivity for PAEs. Electrostatic potential analysis, Fourier transform infrared analysis and the relationship between the adsorption capacity and hydrophobic coefficients (log K ow ) of PAEs indicated the existence of C − H⋯π interaction, π-π stacking and hydrophobic interaction between PAEs and EtP5, as well as O − H⋯O hydrogen bond interaction between PAEs and ChCl-IA. After optimizing the extraction conditions, a PT-μSPE-HPLC-UV method was established for the detection of 8 PAEs in baijiu. The method exhibited linear ranges of 0.5–1000 μg·L −1 for DMP and DEP; 1.0–1000 μg·L −1 for DBP, BBP, and DCHP; 1.5–1000 μg·L −1 for DEHP and DOP; and 2.0–1000 μg·L −1 for DNP (R 2 ≥ 0.998). The limits of detection (LODs, S/N = 3) and limits of quantitation (LOQs, S/ N = 10) ranged from 0.2 to 0.7 μg·L −1 and 0.5 to 2.0 μg·L −1 , respectively. Recoveries of the 8 PAEs in spiked baijiu samples ranged from 83.7 % to 105.5 %. Intra-day and inter-day precisions (RSDs) were no more than 6.0 %. These results demonstrate that the EtP5 doped poly(DES- co -EGDMA) monolithic column is an ideal medium for the separation and detection of PAEs in baijiu.
Ruonan Wang,Yi Yang,Mengyang Huang,Xiaoge Li,Xinying Wu,Zihan Zhu,Jing Yang,Kongyang Wu,Zitai Sang
Arabinoxylan-rich agricultural residues are promising feedstocks for the production of high-value functional sugars and ferulic acid, yet their efficient enzymatic conversion is hindered by the complex crosslinked structures. This study aimed to isolate a novel feruloyl esterase-producing strain from Baijiu distiller’s grains and evaluate its enzyme cocktail for arabinoxylan degradation. A novel strain,Bacillus altitudinisZH-1, was isolated and systematically characterized. Through one-factor-at-a-time optimization of both the medium and cultivation conditions, the feruloyl esterase activity was substantially increased (15.78-fold) compared with the activity obtained in the unoptimized Luria-Bertani (LB) medium. Genomic analysis revealed 103 unique carbohydrate-active enzyme (CAZyme)-encoding genes, including endoxylanases, α-L-arabinofuranosidases, and three putative feruloyl esterases. Studies on enzymatic properties revealed that the extracellular enzyme cocktail exhibited a hemicellulase-dominated profile and no detectable β-xylosidase activity under the assay conditions, with the three key enzymes showing over 76% of their maximum activity at pH 6.0 and 50 °C. In the degradation of insoluble wheat arabinoxylan, the enzyme cocktail released L-arabinose (69.00 mg/g substrate) and a xylooligosaccharides-equivalent fraction (244.00 mg/g substrate), which together accounted for 99.57% of total reducing sugars, along with ferulic acid (1.23 mg/g substrate). When applied to de-starched wheat bran, the enzyme cocktail achieved reducing sugar yields comparable to the commercial enzyme CTec2, while producing significantly higher levels of L-arabinose and xylooligosaccharides. These findings highlight the ZH-1 enzyme cocktail as an arabinoxylan-targeting biocatalyst with no detectable β-xylosidase activity under the assay conditions, showing promising potential for producing high-value functional sugars and ferulic acid from agricultural residues.
危险品化学品经营许可证（带存储）