食品中亚硝酸盐与硝酸盐的测定

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

Using Bruker’s Hysitron PI 88 SEM PicoIndenter equipped with tilt and rotation stages in conjunction with the QUANTAX EBSD system enables a more robust characterization of metallic materials by combining high resolution phase and grain orientation mapping capabilities with targeted nanomechanical property measurements. This combination could also be used to extend the scope of research related to other advanced textured, anisotropic, or multi-phase materials.

二氧化硅是用于检测、控制和尽量减少涡轮机、换热器和锅炉结垢的一种关键度量。在线实时测量活性二氧化硅可尽量降低因结垢而产生的维修/更换成本，实现安全高效的长期运行，这款在线二氧化硅分析仪可用于对二氧化硅超标的生产用水的去除或回收进行即时或自动的决策。连续实时二氧化硅监测可快速通知离子交换树脂的RO穿透或饱和情况，从而使系统效率最大化，尽量减少维修停机时间。Orion 8030cX 在线二氧化硅分析仪可配置为在二氧化硅峰值出现时发送警告/警报或测量数据来警告用户，触发纠正措施，防止下游出现问题。

Ramina过程分析仪为离线手动或自动湿态化学测试提供了一种快速且易于操作的替代方案。相比于传统的拉曼过程监控系统，它的安装和使用变得更加简单。Ramina为用户开始收集数据提供了所需的全部设备，包括拉曼光谱仪和光纤探针，以及便携式监视器、鼠标、键盘和激光安全护目镜。工厂校准可确保Ramina系统随时能够投入使用，其固态结构提供了长期稳定性。这意味着用户可以进行连续、高精度的测量，而无需频繁校准。用户还可以并联使用多个系统来同时测试不同的反应容器，或者在一个反应容器中组合使用多个探针。