Histamine intolerance results from a disequilibrium of accumulated histamine and the capacity for histamine degradation. An impaired histamine degradation based on reduced DAO activity and the resulting histamine excess may cause numerous symptoms mimicking an allergic reaction. For that, the determination of histamine in blood or in food products has great importance to identify risk factors. A new histamine-selective electrode is proposed using cucurbit[6]uril (CB[6]), as ionophore, in the analysis of biological samples. The selection of this smart supramolecular organic framework was based on its apparent stability constant of histamine-CB[6] (log β) of 4.33. The optimized electrode based on a polymeric membrane (PVC) combines the histamine-selective ionophore with 2-nitrophenyl octyl ether as solvent mediator and potassium tetrakis(4-chlorophenyl)borate as anionic additive. Furthermore, multi-walled carbon nanotubes particles were included in the membrane composition to partly lower the detection limit of the method, while improving stability and lowering the response drift (± 4 mV). The electrodes showed a rapid response (≃ 13 s) in the pH operational range of 2.7-5.4, with a Nernstian slope of 30.9 ± 1.2 mV/dec, a detection limit of (3.00 ± 0.61) × 10-7 mol/L, and a lower limit of the linear range of (3.00 ± 0.00) × 10-7 mol/L. After miniaturization, the electrode was used as a detector in a sequential-injection lab-on-valve flow setup. The optimized flow conditions were achieved for sample injection volumes of 197 μL propelled towards the cell under detection, at a flow rate of 30 μL/s during 100 s, making the analysis of 30 samples per hour possible. The developed system was used to analyze spiked blood serum samples previously cleaned by using solid-phase extraction. The sample pretreatment of the serum samples using Oasis MCX cartridges showed outstanding efficiency for histamine determination. The recovery values for three different levels of histamine concentration (1 × 10-4 mol/L, 1 × 10-5 mol/L, and 1 × 10-6 mol/L) were (97 ± 6)%, (103 ± 1)%, and (118 ± 9)%, respectively, showing that this method was suitable for biological samples.

中文翻译：

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一种用于血清中组胺评估的更简单的电位测定方法。

组胺不耐受是由积累的组胺和组胺降解能力的不平衡引起的。基于 DAO 活性降低的组胺降解受损和由此产生的组胺过量可能导致许多模仿过敏反应的症状。为此，血液或食品中组胺的测定对于识别危险因素具有重要意义。提出了一种新的组胺选择性电极，使用葫芦[6]脲（CB[6]）作为离子载体，用于生物样品的分析。这种智能超分子有机框架的选择是基于其组胺-CB[6] (log β) 4.33 的表观稳定性常数。基于聚合物膜 (PVC) 的优化电极将组胺选择性离子载体与作为溶剂介质的 2-硝基苯基辛基醚和作为阴离子添加剂的四(4-氯苯基)硼酸钾结合在一起。此外，膜组合物中包含多壁碳纳米管颗粒，以部分降低该方法的检测限，同时提高稳定性并降低响应漂移（±4 mV）。电极在 2.7-5.4 的 pH 操作范围内表现出快速响应（≃ 13 s），能斯特斜率为 30.9 ± 1.2 mV/dec，检测限为（3.00 ± 0.61）× 10-7 mol/L，线性范围的下限为（3.00±0.00）×10-7 mol/L。小型化后，该电极被用作顺序进样阀上实验室流动装置中的检测器。优化的流动条件是在 100 秒内以 30 微升/秒的流速将 197 微升的样品注射体积推向被检测的电池，从而使每小时分析 30 个样品成为可能。所开发的系统用于分析之前使用固相萃取法清洗过的加标血清样品。使用 Oasis MCX 小柱对血清样品进行样品预处理显示出出色的组胺测定效率。三种不同组胺浓度水平（1×10-4 mol/L、1×10-5 mol/L和1×10-6 mol/L）的回收率分别为（97±6）%、（103± 1)% 和 (118 ± 9)% 分别表明该方法适用于生物样品。使每小时分析 30 个样品成为可能。所开发的系统用于分析之前使用固相萃取法清洗过的加标血清样品。使用 Oasis MCX 小柱对血清样品进行样品预处理显示出出色的组胺测定效率。三种不同组胺浓度水平（1×10-4 mol/L、1×10-5 mol/L和1×10-6 mol/L）的回收率分别为（97±6）%、（103± 1)% 和 (118 ± 9)% 分别表明该方法适用于生物样品。使每小时分析 30 个样品成为可能。所开发的系统用于分析之前使用固相萃取法清洗过的加标血清样品。使用 Oasis MCX 小柱对血清样品进行样品预处理显示出出色的组胺测定效率。三种不同组胺浓度水平（1×10-4 mol/L、1×10-5 mol/L和1×10-6 mol/L）的回收率分别为（97±6）%、（103± 1)% 和 (118 ± 9)% 分别表明该方法适用于生物样品。