Peiying Shi,Chunlei Yang,Ya Su,Liying Huang,Xinhua Lin,Hong Yao
This study has developed a reliable and precise high performance liquid chromatography-tandem mass spectrometry method for the simultaneous determination of five phenolic acids and four flavonoid glycosides in rat plasma after a single intravenous administration of Kudiezi injection (KI). Chromatographic separation was carried out on an Ultimate®XB-C18column (4.6 × 100 mm, 3.5 μm) using a gradient elution program with a mobile phase consisting of water containing 0.5% acetic acid and acetonitrile at a flow rate of 0.6 mL/min. Detection was performed on a triple-quadrupole tandem mass spectrometry using multiple reaction monitoring in negative electrospray ionization mode. The calibration curves of all analytes showed good linearity (R2> 0.990). The results of selectivity, intra-day and inter-day precisions, extraction recoveries, matrix effects and stability were satisfactory. Pharmacokinetic parameters showed that luteolin-7-O-β-d-gentiobioside, luteolin-7-O-β-d-glucuronide, luteolin-7-O-β-d-glucoside and apigenin-7-O-β-d-glucuronide were eliminated quickly (0.07 h
Sulfonated phenol–formaldehyde (SPF) resin used as a cross-linker for petroleum reservoir conformance control was synthesized under alkaline conditions. The reaction process of SPF resin was evaluated by measuring the solution’s viscosity with respect to phenol–formaldehyde (PF) resin. The molecular structure of SPF resin was characterized by both FTIR and HPLC–MS/MS. The influence of the formaldehyde/phenol molar ratio (F/P) and the sodium formaldehyde sulfoxylate/phenol molar ratio (S/P) on the properties of SPF were analyzed in terms of the storage time, coagulation value, molecular size, and zeta potential. The results indicate that the presence of formaldehyde sodium bisulfite could slow down condensation reaction. Phenol rings were connected by methylene bridges in the position of o–p, and sulfonated SPF resin molecules all had one sulfonate group on the oligomer structure. The storage time decreased from 87 to 6 days, and the zeta potential decreased from −3.02 to −7.70 mV with the increase in F/P (1.2–2.0). Meanwhile, the sedimentation value and the diameter increased from 3.291 × 104to 5.045 × 104mg/L and from 2.7 to 5.3 nm, respectively. Sulfonation could significantly increase the storage time and dispersion stability. With the increase in S/P (0.1–0.35), the storage time increased from 15 to 86 days, the sedimentation value increased from 1.927 × 104to 5.269 × 104mg/L, and the diameter decreased from 6.3 to 3.0 nm. This paper can present new ideas for improving the storage stability and salt tolerance of phenol–formaldehyde resin and further improving the range of its applications, which has essential reference significance.Keywords:phenol–formaldehyde resin;sulfonation;characterization;HPLC–MS/MS
Developing efficient and reliable adsorbents with simplified synthesis and mixed-mode performance is crucial for the accurate quantitative analysis of diverse coexisting environmental pollutants. A magnetic carboxylated hypercrosslinked organic polymer (Fe 3 O 4 /HCP-COOH) with reverse phase/cation exchange mixed-mode performance was synthesized through a two-stage process: (1) Fabrication of HCP-COOH via FeCl 3 -catalyzed Friedel-Crafts alkylation using 1,4-phenylenediacetic acid and 1,4-bis(chloromethyl)benzene; (2) In situ growth of Fe 3 O 4 nanoparticles on HCP-COOH through coprecipitation, utilizing FeCl₃ dually as polymerization catalyst and iron precursor to enhance process efficiency and waste minimization. The nanocomposite functioned as a mixed-mode sorbent for magnetic solid-phase extraction (MSPE), integrating dual retention mechanisms to selectively extract hydrophobic polycyclic aromatic hydrocarbons (PAHs) and cationic quaternary ammonium pesticides (QUATs), with subsequent analysis by GC-MS for PAHs and HPLC-MS/MS for QUATs respectively. Following optimization of adsorption pH, eluent composition, and contact time, the method exhibited high sensitivity with limits of detection (LODs) of 0.80-7.93 ng L⁻¹ for 15 PAHs and 0.02-16.31 ng L⁻¹ for 4 QUATs. Validation showed satisfactory recoveries of 89.5-98.3% (RSDs ≤11.2%) in snowmelt and 90.4-101.8% (RSDs ≤11.6%) in lake water (n=3), confirming practicality for simultaneous monitoring of hydrophobic and cationic contaminants in complex environmental water, offering significant advantages in multi-residue analysis for environmental monitoring applications.