Enantiomeric determination of chiral drugs in environmental waters

Aquesta Tesi Doctoral se centra principalment en el desenvolupament i aplicació de mètodes analítics sensibles i selectius per a la determinació enantiomèrica d'un grup de catinones en mostres d'aigües mediambientals mitjançant l'ús d'extracció en fase sòlida (SPE) seguida de cromatografia líquida (LC) quiral acoblada amb espectrometria de masses d'alta resolució (HRMS). Amb aquesta finalitat, en la primera part d'aquesta Tesi, es van desenvolupar mètodes de separació LC quirals per al grup d'anàlits d'estudi. Es van avaluar diferents fases estacionàries quirals i diferents modes d'elució. També es van provar i optimitzar diferents variables per aconseguir enantioseparacions satisfactòries. A la segona part, el mètode d'enantioseparació optimitzat es va acoblar a HRMS per a la determinació enantiomèrica de cinc catinones en mostres d'aigües mediambientals. Per millorar la selectivitat dels mètodes, es van avaluar diferents sorbents d'SPE (incloent sorbents de mode-mixt d'intercanvi catiònic i d'empremta molecular) per a l'extracció de les catinones. Es van optimitzar diferents paràmetres d'SPE per aconseguir recuperacions i selectivitat elevades per als anàlits. El mètode desenvolupat es va aplicar amb èxit per a la determinació enantiomèrica de catinones en mostres d'aigua de riu i efluents d'aigües residuals.Esta Tesis Doctoral se centra principalmente en el desarrollo y aplicación de métodos analíticos sensibles y selectivos para la determinación enantiomérica de un grupo de catinonas en muestras de aguas medioambientales mediante el uso de extracción en fase sólida (SPE) seguida de cromatografía líquida (LC) quiral acoplada con espectrometría de masas de alta resolución (HRMS). Para este propósito, en la primera sección de esta Tesis, se desarrollaron métodos de separación quirales por LC para los analitos de interés. Se evaluaron diferentes fases estacionarias quirales y en diferentes modos de elución. También se probaron y optimizaron distintos parametros para lograr enantioseparaciones satisfactorias. En la segunda sección, se acopló el método optimizado de separación enantiomérica al HRMS para la determinación enantiomérica de cinco catinonas en muestras de aguas medioambientales. Para mejorar la selectividad de los métodos, se evaluaron diferentes sorbentes de SPE (incluyendo los de modo-mixto de intercambio catiónico y de huella molecular) para la extracción de las catinonas. Se optimizaron diferentes parámetros de SPE para lograr altas recuperaciones y selectividad para los analitos. El método desarrollado se aplicó con éxito para la determinación enantiomérica de catinonas de interés en muestras de agua de río y efluentes de aguas residuales.This Doctoral Thesis is mainly focused on the development and application of sensitive and selective analytical methods for the enantiomeric determination of a group of cathinones in environmental water samples on the use of solid-phase extraction (SPE) followed by chiral liquid chromatography (LC) coupled with high-resolution mass spectrometry (HRMS). For this purpose, in the first section of this Thesis, chiral LC separation methods were developed for target analytes. Different chiral stationary phases were evaluated for their chiral recognition abilities in different elution modes. The factors that affected the enantioseparation were optimized to achieve successful enantioseparations. In the second section, the optimized enantioseparation method was coupled to HRMS for the enantiomeric determination of five cathinones in environmental water samples. To improve the selectivity of the methods, different SPE sorbents (including mixed-mode cationic exchange sorbents and molecularly imprinted polymers) were assessed for the extraction of target cathinones. Different SPE parameters were carefully optimized to achieve high recoveries and selectivity for the analytes. The developed method was successfully applied for the enantiomeric determination of target cathinones in river water and effluent wastewater samples

Determinants of life satisfaction in older adults with diabetes in China: a national cross-sectional study

BackgroundThe life satisfaction (LS) of individuals among older adults with diabetes should not be neglected. However, current research provides limited insight into the LS of older adults with diabetes in China. Therefore, the primary objective of this study is to assess the current life satisfaction status of older adults with diabetes in China, to delve into the factors influencing it, and to identify the key factors.MethodsThis study selected 1,304 patients with diabetes from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) database for analysis. A multivariate logistic regression model was used to analyze the factors influencing life satisfaction among diabetic patients, and a random forest model was further utilized to rank the importance of significant influencing factors.Results30.14% of older adults with diabetes were dissatisfied with their lives. Multivariate Logistic regression analysis shows that self-assessed health status, self-assessed economic status, depressive symptoms, exercise, living arrangements, hearing impairment, and cognitive impairment all significantly affect the life satisfaction of older adults with diabetics. The OR values for self-assessed health and self-assessed economic status are relatively high, patients with fair and poor self-assessed health was 5.03 times and 9.72 times higher risk of life dissatisfaction compared to those with good self-assessed health (fair: OR = 5.03, 95% CI: 3.46–7.31; poor: OR = 9.72, 95% CI: 6.20–15.26). The risk of feeling dissatisfied with life was 7.69 times higher in patients with poor self-assessed economic status than in those with good self-assessed economic status (OR = 7.69, 95%CI: 4.25–13.89). The random forest results showed that the order of importance from highest to lowest was self-assessed health status, self-assessed economic status, depressive symptoms, exercise, living arrangements, hearing impairment, and cognitive impairment.ConclusionOur study reveals that the current rate of life satisfaction among older adults with diabetes is significantly high. Therefore, it is essential to implement measures from multiple perspectives for effective prevention and intervention. Among these factors, priority should be given to interventions focusing on economic support and health management, as these measures may serve as crucial protective factors in enhancing the well-being of older adults with diabetes

Spatio-temporal evolution characteristics and influencing factors of carbon emission reduction potential of the transportation industry in China

Abstract Scientific estimation of China's transport carbon reduction potential (CERP) and exploration of its temporal and spatial characteristics and influencing factors are important bases for formulating emission reduction policies. Based on the dual perspective of equity and efficiency, we assess the CERP of the transportation industry in 30 provinces in China from 2010 to 2019 and analyze its spatio-temporal evolution characteristics using the Kernel density estimation method. Then, the Dagum Gini coefficient is used to measure the regional differences and sources of the CERP, and its influencing factors are analyzed with the help of the random effects panel Tobit regression model. The results show that: (1) from 2000 to 2019, the CERP of the transportation industry in China and the three regions show an oscillating upward trend, with a spatial pattern of "high in the west and low in the east". (2) The overall difference in the CERP of the transportation industry shows a fluctuating downward trend, and the difference in hypervariable density has the highest contribution rate. The inter-regional differences between the West and other regions are the largest, and the intra-regional difference pattern shows the pattern of western > central > east. (3) The technological improvement, industrial structure, and scale of transportation industry development have a significant positive impact on the CERP of the transportation industry. The influence of urbanization influence and environmental regulation have a significant negative influence

Preparation and evaluation of molecularly imprinted polymers as selective SPE sorbents for the determination of cathinones in river water

In this study, a series of molecularly imprinted polymers (MIPs) were synthesised using (1R,2S)-(–)-ephedrine or (1S,2S)-(+)- pseudoephedrine as template, methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross-linking agent. A highly selective and sensitive method using the best performing MIP as sorbent in the solid-phase extraction (SPE) followed by liquid chromatography-high resolution mass spectrometry was established for the enantiomeric determination of five cathinones in river water samples. The SPE parameters (sample loading volume and pH, washing and elution solutions) were optimised so that recoveries and selectivities for the analytes were high. The enantioselectivity of MIPs towards the enantiomers of the analytes during the SPE process was also investigated. Under optimal conditions, the method developed provided satisfactory recoveries ranging from 67.6 to 83.2% with a negligible matrix effect ranging from -5.5 to 1.8 %. The detection limits ranged from 0.3 to 0.8 ng L-1 and quantification limits ranged from 1.0 to 2.0 ng L-1. The application of the method to the analysis of the river water samples indicated that methedrone and butylone were present at low concentration levels in river water samples