Determination of the endocrine disrupter bisphenol—A in the blood of uremia patients treated by dialysis

Summary Automated solid-phase extraction (SPE) then high-performance liquid chromatography have been studied for determination of the endocrine disrupter bisphenol-A (BPA) in blood. Electrochemical detection was used for selective and sensitive detection of BPA. Determination of BPA in the blood of uremia patients treated by dialysis has not yet been reported. Acidified blood and acidified SPE eluent were used to suppress the ionization of BPA and thus retain the compound on a C₁₈ column. Because artificial dialysis can be performed for periods longer than 20 years, for reasons of safety the amount of BPA migrating from the artificial dialyzer into the blood of a uremia patient was compared for different sterilization methods and for different artificial dialyzers manufactured from different materials.     

原位被动采样技术*

本文介绍了近些年来环境监测中三种新的原位被动采样技术-透析装置（Dialysis peepers）法、薄膜扩散平衡 (DET) 技术和薄膜扩散梯度 (DGT) 技术。综述了三种技术的原理、装置和特点。着重论述了三种技术在环境中的应用研究,包括透析装置以及DET 技术和DGT联用技术测量水体和沉积物孔隙水中可溶性金属的浓度;DGT技术可以作为一种预测重金属生物可利用性的新方法。DGT技术与其他技术（如DET、高离子选择电极、配体交换法、HPLC-ICP-MS等）联用可以更好地测量环境中重金属的形态。最后展望了原位被动采样技术未来的发展。     

Association between benzalkonium chloride and a poly( acrylic acid) gel. Study by microfiltration and membrane dialysis

Interactions between benzalkonium chloride (BAK) and the respective polymers, and the related availability of BAK in the corresponding solution, were studied for aqueous preparations of hydroxyethylcellulose (HEC), polyvinyl alcohol (PVA) and crosslinked poly(acrylic acid) (PAA). The study was performed by means of a crossflow filtration process with an alumina membrane. In the presence of the PAA gel, the rejection rate of BAK is much higher than with HEC or PVA. These results can be explained by the association of the benzalkonium cation BAK⁺ with the negative carboxylate groups or the PAA. This effect, which was confirmed by dialysis experiments, leads to the trapping of BAK⁺ inside the polymer network and could be of interest in the reduction of the harmful effects of BAK observed in the treatment of eye diseases.     

In‐vitro Aluminum Determination and Preconcentration in Blood of Dialysis Patients Based on Ionic Liquid Dispersive Liquid‐Liquid Biomicroextraction by 2‐Amino‐3‐(1H‐imidazol‐4‐yl)propanoic Acid

In this study, trace amounts of aluminum in serum of dialysis patients were chelated with 2‐Amino‐3‐(1H‐imidazol‐4‐yl)propanoic acid (Histidine) and determined by electro‐thermal atomic absorption spectrometry (ETAAS). A fast and efficient method based on ionic liquid dispersive liquid‐liquid bio‐micro‐extraction (IL‐DLLBME) was developed for the determination of Al cation in human blood serum samples. In this work, a small amount of 1‐Hexyl‐3‐methylimmidazolum hexafluorophosphate ([HMIM] [PF₆]) as an extractant solvent was dissolved in acetone as a dispersant solvent and then the binary solution was rapidly injected by a syringe into the serum containing Al³⁺,Which have already in‐vitro chelated by Histidine amino acid (Al‐His) at pH = 6.5. After separation, the settled IL‐phase was dissolved in ethanol up to 200 μL and 20 μL of samples injected into the ET‐AAS by auto‐sampler. Various parameters have been studied and optimized for 10 mL of sample. Under the optimum conditions, the enrichment factor (EF), limit of detection (LOD) and working range (peak area mode) were obtained 53, 15 ng L^?1 and 0.05‐4.1 μg L^?1 respectively. In vitro Al chelation showed that His can significantly decrease aluminum concentration in serum of dialysis patients. Validation of methodology was confirmed by standard reference material (SRM).     

Dynamic polymer membranes displaying tunable transport properties on constitutional exchange

Functional dynamic polymers, “dynamers”, are used to design new membrane materials. Our efforts involve the synthesis and the fabrication of dynamic thin-layer supported solid membrane films. The transport performances of (permeability, selectivity and partition coefficients) are evaluated by using the solution-diffusion model. The membrane performances designed to transport ionic salts NaCl and KCl depend and are based on encoded molecular features of the monomeric subcomponents. Thanks to the possibility to combine the structural and functional features of different monomers, the heteropolymeric membrane materials can exhibit very different properties from their original homopolymeric components. In the examples developed here, this strategy revealed itself as a versatile way for the synthesis of new membranes presenting different permeabilities and preserving their selectivity (SK_+/Na₊∼1.4)$(S_{{\text{K}}^{+}/\text{N}{\text{a}}^{+}}\sim 1.4)$.     

Determinations of Some Trace Metals in Dialysis Solutions by Atomic Absorption Spectrometry After Preconcentration

Abstract

A method is presented for the determination of copper, lead, iron, cadmium, cobalt and nickel in dialysis solution at μg/1 level by atomic absorption spectrometry after preconcentration. The preconcentration is based on chelate formation of the investigated metals with ammonium pyrrolydine dithiocarbamate and on retention of the chelates on Amberlite XAD-4 in a short column. The relative standard deviations for the determinations were found to be lower than 0.08.     

维持性非卧位腹膜透析患者血清镁与血脂代谢的相关性研究

目的研究维持性非卧位腹膜透析患者血清镁水平与血脂代谢的相关性。方法选取57例维持性非卧位腹膜透析的终末期肾病患者,抽取空腹静脉血,测定血脂、血清镁、血钙、血磷水平并行相关性分析。结果血清镁和脂蛋白a、高密度脂蛋白、甘油三酯水平呈正相关（P＜0.05）。血清镁和低密度脂蛋白、总胆固醇、载脂蛋白A、载脂蛋白B无相关性（P＞0.05）。结论持续血脂紊乱是维持性非卧位腹膜透析患者常见的并发症,其血清镁和血清脂蛋白a、高密度脂蛋白、甘油三酯水平有一定的相关性。