pH 梯度洗脱用于改善单克隆抗体带电变体 的分离

文献名： Structural, morphological and optical properties of Bi NPs obtained by laser ablation and their selective detection of L-cysteine 作者： Ramon Gabriel Teixeira Rosaa, Celso de Araujo Duartea , Wido Herwig Schreinera, Ney Pereira Mattoso Filhoa, Arandi Ginane Bezerra Jr.b, Andersson Barisonc, Fernanda Maria Marins Ocamposc a Departamento de Física, Universidade Federal do Paraná Centro Politécnico, CP 19044, 81531-990 Curitiba (PR), Brazil b Departamento Acadêmico de Física, Universidade Tecnológica Federal do Paraná, 80230-901 Curitiba (PR), Brazil c Departamento de Química, Universidade Federal do Paraná Centro Politécnico, CP 19081, 81531-990 Curitiba (PR), Brazil 摘要：In the present work we show the results of the investigation of the properties of bismuth nanoparticles (NPs) obtained by the laser ablation in water. The samples were characterized by various techniques: UV/vis spectroscopy, dynamic light scattering, transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, nuclear magnetic resonance and zeta potential. The NPs were metallic and surface oxidated, exhibiting absorption peak at 257 nm due to the surface plasmon resonance. The interaction between the NPs and various amino acids was studied and revealed a selective sensibility to cysteine on a range of concentration from 80 to 720 μM, which we attribute to a dimerization of cysteine to cystine probably complexed to the nanoparticle surface by electrostatic interactions, leading to the modification of the NP absorption spectrum. 关键词：Bismuth; Nanoparticles; Laser ablation; Cysteine

纯水是制备溶出溶剂或生物相关溶液的重要成分，因此水质的好坏会影响结果。一旦水质选择不当，就会引入污染物，主要有以下几种类型。使用高质量纯水来制备溶出溶剂，是获取精确、可重现结果并满足监管要求的重要保障。

金属检测技术的局限性之一是对于像电线和大头针这样相对比较小的、长条形金属异物就很难检测出来。这些类型的污染物通常表现出“方向效应”，即金属探测器所检测到的信号很大程度上取决于污染物与探测孔的方向关系。方向效应给金属检测系统带来了挑战——这一挑战乍一看并不是那么严重，但事实上它可能会给消费者的安全以及品牌声誉带来严重的影响和危害。

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