In the present study, silica-coated magnetic nanoparticles functionalized with vancomycin (Fe3O4@SiO2@VAN) were synthesized. The Fe3O4@SiO2@VAN nanocomposite was used as a sorbent for the magnetic solid-phase extraction (MSPE) of polycyclic aromatic hydrocarbons (PAHs) from environmental water, followed by GC-MS. The nanocomposite was characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, and nitrogen sorption. Various experimental parameters were optimized, including extraction condition and desorption condition. Results show that Fe3O4@SiO2@VAN combined the advantages of nanomaterials and magnetic separation technology, showing excellent dispersibility and high selectivity for PAHs in environmental water sample. Under the optimal extraction conditions, an analytical method was established with the sensitive limit of detection (LOD) of 0.03–0.16 μg L−1. The method was successfully applied for the analysis of environmental water samples. The relative standard deviations (%) were in the range of 0.50–12.82%, and the extraction recovery (%) was in the range of 82.48% and 116.32%. MSPE-coupled gas chromatography–mass spectrometry quantification of PAHs is an accurate and repeatable method for the monitoring of PAH accumulation in environmental water samples. It also provides an effective strategy for the tracing and quantification of other environmental pollutants in complex samples.
29 September 2022 in Journal of Analytical Methods in Chemistry
To study the differences in phenolic compounds between tobacco smokers’ saliva and mainstream smoke, a method was developed for the analysis of 12 phenolic compounds in saliva and mainstream smoke based on ultrahigh‐performance liquid chromatography with fluorescence detection (UPLC‐FLD). The contents and distributions of phenolic compounds in tobacco smokers’ saliva and mainstream smoke were compared. The results were as follows: (1) Phenolic compounds were quantitatively analyzed by the internal standard method using 4‐fluorophenol as an internal standard. For smokers’ saliva samples, the limits of quantification (LOQs) ranged from 2.2 to 19.1 μg/L, and the recoveries were from 80.2% to 119.2% at the three spiked levels. For mainstream smoke samples, the LOQs ranged from 0.03 to 0.26 μg/cig, and the recoveries ranged from 84.9% to 107.0% at the three spiked levels. (2) The contents of phenolic compounds from 14 cigarettes in mainstream smoke and smokers’ saliva were determined. In mainstream smoking, the main phenolic compounds were hydroquinone, catechol, phenol, meta‐ and para‐Cresol, and o‐methylhydroquinone. In smokers’ saliva, the main phenolic compounds were phenol and meta‐ and para‐Cresol and the contents of phenolic compounds in smokers’ saliva from different cigarettes were significantly different. (3) The content distribution patterns of phenolic compounds in smokers’ saliva differed from those in mainstream smoke. The predominant phenolic compound in mainstream smoke was dihydroxybenzene, while monophenols predominated in smokers’ saliva. (4) The contents of phenolic compounds from five kinds of cigarettes were analyzed in the saliva of different smokers using principal component analysis, which indicated that cigarettes with different sensory effects were clearly distinguished by differences in the contents of phenolic compounds in saliva.
Alkaloid enantiomers have different physiological and pharmacological effects, and different chiral compositions have a large impact on cigarette sensory and use safety. Studying the effects of different configurations of alkaloid enantiomers on cigarette sensory is important for the development of tobacco products, but the chiral separation of alkaloid enantiomers has become the core problem. Here, the application of a C18 column coupled with a polysaccharide-based chiral column to separate and detect four pairs of alkaloid enantiomers in tobacco and cigarette smoke of different brands was investigated. Results showed that the tandem technology of the two columns enabled the baseline separation of four pairs of alkaloid enantiomers. The resolution of enantiomers of alkaloids in different tobacco samples differed in content and ratio, showing different chiral distribution characteristics. According to the different distribution characteristics of alkaloid enantiomers, tobacco samples of different brands can be distinguished and real cigarettes can be identified.