Se pu = Chinese journal of chromatography最新文献

A gas chromatography-based method was developed for the simultaneous and rapid determination of ethylene oxide (EO), 2-chloroethanol (ECH), and ethylene glycol (EG) residues in medical devices after EO sterilization. A sample weighing 2.5 g was added with 5 mL of ethanol as the extraction medium, and the residual substances in the sample were extracted at 40 ℃ for 4 h. The samples were separated on a DB-WAX capillary column (30 m×0.53 mm×1.0 μm) and determined using a hydrogen flame ionization detector. The temperature was maintained at 40 ℃ for 5 min, increased to 120 ℃ at a rate of 40 ℃/min, held for 5 min, and then increased to 200 ℃ at a rate of 6 ℃/min, held for 2 min. The flow rate of the nitrogen gas was 3 mL/min. The split ratio was 5∶1. The inlet and detector temperatures were 200 and 300 ℃, respectively. The changes in the chromatographic peak areas over time (0.5-10 h) under different temperatures (20, 30, 40, and 50 ℃) were investigated, and the optimal extraction condition was determined to be 40 ℃ for 4 h. In the experiments, quantification was performed using an external standard method. EO, ECH, and EG exhibited good peak shapes and separation effects as well as good linearity within their respective ranges. The linear correlation coefficients for EO, ECH, and EG were greater than 0.99. The limits of detection (LODs) for EO, ECH, and EG were in the range of 0.10-0.40 μg/g, and the limits of quantification (LOQs) were in the range of 0.30-1.20 μg/g. The average recoveries under different spiked levels were in the range of 91.08%-116.08%, and the relative standard deviations (n=6) were in the range of 0.56%-8.45%. EO, ECH, and EG residues were found to exist at different levels in the medical devices tested. In particular, disposable infusion sets must be paid careful attention. ECH and EG were not detected in disposable sterile medical devices made of non-polyvinyl chloride materials, which may be due to the fact that the products themselves did not contain chloride ions, they were not exposed to chlorine-containing substances during their production, sterilization, storage, transportation, use, etc. This study established a method to detect EO residues in disposable medical devices, and has the advantages of simple operation, excellent specificity, accurate quantification, and good reproducibility. It can simultaneously detect three residual substances in medical devices while meeting the actual detection requirements for EO, ECH, and EG residues. The method can be used to scientifically and effectively evaluate the risk of EO residues in single-use medical devices sterilized with EO, and will be helpful for improving the quality of medical devices, ensuring the safety of device use, and providing a reference for regulatory supervision and testing.

Understanding the previous protection and restoration efforts and the current state of cultural relics is essential before compiling a conservation and restoration plan. The lack of detailed archival records for some early conservation operations, the identification of restoration materials necessitates the use of scientific analytical methods. In this study, the composition and spatial distribution of historical restoration materials on five iron relics were investigated through pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and ultraviolet-induced visible luminescence imaging (UVL). The relics studied were iron weight 20791, iron adze head 2335, and iron axe 2334 from the Gansu Provincial Museum, iron sword D0008 from the Zhaotong Municipal Museum, and iron sword 450 from the National Museum of China. All five relics had undergone restoration without accompanying archival records. UVL revealed the distribution of various conservation materials. Notably, two distinct layers of the conservation material were observed on iron axe 2334. Differences in the fluorescence color and intensity of iron sword 450 provided information regarding the sampling strategy. The samples were collected under ultraviolet light emitting diode illumination to ensure representativeness and minimize damage to the relics. Through Py-GC/MS, the coating materials for iron weight 20791 and iron adze head 2335 were identified as boiled tung oil mixed with rosin resin. Iron axis 2334 had a two-layer coating: a base layer of boiled tung oil and a top layer of shellac. The coating material for iron sword D0008 was determined to be paraffin wax. The protective layer of iron sword 450 included multiple materials, including shellac, polystyrene, and bisphenol-A-type epoxy resin. This study confirms that UVL combined with Py-GC/MS serves as an effective technique for analyzing historical restoration materials. UVL guided the selection of representative samples for Py-GC/MS, reducing the time and amount of sampling required and minimizing further damage to the relics. This research provides valuable data for the restoration archives of five iron artifacts, offering a scientific basis for conservators to evaluate conservation methods, devise future conservation strategies, and exclude ineffective conservation materials.

Ion chromatography is a technique commonly used to separate strongly polar and ionizable substances; it can be used to separate, identify, and quantify ionizable compounds in complex samples when coupled with mass spectrometry, and is currently being used in the application of food analysis, drug analysis, metabolomics and clinical poisoning analysis. Herein, we review the development of ion chromatography-mass spectrometry (IC-MS), its progress over the past 20 years, and future trends in the abovementioned areas. The IC-MS research progress and applications for the determination of inorganic anions, organic acids, polar pesticides, biogenic amines, and sugars in the food field are discussed. Drug analysis applications are discussed mainly in relation to the analysis of drug impurities, identifying drug degradation products, and determination of plasma concentration, while the separation and analysis of strongly polar metabolites, such as organic acids, sugar phosphates, and nucleotides in biological matrices are discussed in relation to metabolomics. Advances in the analysis of strongly polar or ionizable toxic compounds, such as alkyl methylphosphonic acid, methylphosphonic acid, glyphosate, 3-nitropropionic acid, and indandione rodenticides, are mainly discussed in clinical poisoning analysis field. This paper is expected to become a useful reference for the further expansion and application of IC-MS in the life and health fields.

Continuously promoting new curriculum standards is a key aim of the Ministry of Education of China. With this in mind, this paper introduces a comprehensive teaching experiment for undergraduate instrumental analysis courses that aims to improve students' material-preparation and instrumental-analysis skills through practice. Herein, a covalent organic framework-based core-shell stationary phase material (SiO₂@COF_TTA-DHTA) is prepared via a one-pot method and characterized in detail, after which its chromatographic properties are evaluated by high performance liquid chromatography (HPLC). The experimental process includes material synthesis and characterization, as well as studying the chromatographic-retention behavior and chromatographic-separation performance of the material. By the combining theoretical science and experimental teaching, this experiment not only deepens students' understanding of the properties of functional materials and their applications, but also improves their experimental-design and critical-thinking skills. This experiment not only cultivates students' interests in scientific research, but also exercises their experimental, operational, innovative-thinking, and practical abilities, while concurrently enhancing their sense of social responsibility and historical mission, thereby delivering the all-round educational goals of experimental teaching.

Hair dyes (HDs) are mainly composed of various benzene series, amines, and phenolic compounds. These ingredients are well known to have allergenic, teratogenic, and carcinogenic properties. As such, the presence of these ingredients in HDs has received increased attention in recent years. At present, the applications of traditional analytical and detection methods and commercial chromatographic columns are limited by problems such as poor qualitative analysis and inaccurate quantification. Thus, the development of new analytical and detection technologies and stationary phases is an urgent endeavor. Moreover, HDs contain complex compounds and exhibit significant matrix interference. Hence, appropriate sample pretreatment methods are necessary to analyze HDs. In this study, the 3D nonpolar rigid structure of triptycene (TP) was combined with the polar flexible chains of polyethylene glycol (PEG) to design and synthesize a TP derivative, TP-PEG, as a stationary phase for chromatographic columns. The stationary phase enabled the expansion of the selection range for polar and nonpolar analytes. Subsequently, gas chromatography-mass spectrometry (GC-MS) was used to quantitatively analyze 22 ingredients in HDs. The experimental results demonstrated that analytes with different polarities exhibited sharp and symmetrical peak shapes on the stationary phase, and all 22 analytes achieved baseline separation on the chromatographic column. The 22 ingredients in HDs showed good linear relationships within their respective ranges, with correlation coefficients greater than 0.9985. The average recovery rates at three spiked levels were in the range of 89.2%-103.2%, and RSDs were less than 5%. Compared with traditional methods, the proposed method has higher efficiency and better accuracy, thus verifying the excellent separation performance of the new stationary phase and the effectiveness of the established GC-MS detection method. The findings indicated the applicability of the developed method to the detection and analysis of various compounds in HDs.