气相色谱仪在食品检测中的应用

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

当称量仪器用于与质量控制相关的测量时，校准是必须定期执行的关键操作之一。国际上有许多标准规范都有这方面的要求，例如ISO9001、GMP法规以及与食品安全相关的一些标准。然而关于校准的定义、实施和校准的具体操作在全球范围内并没有一个完全统一的标准。在此，我们首先需要了解一下什么是校准，以及与调整和检定的区别。

无比小巧可以单手控制的手持式拉曼光谱仪Mira XTR，它内置了16200条由瑞士万通公司独立开发的拉曼光谱数据库，用于快速鉴别各类化学品、危险品、芬太尼和药物。适合公安、安监和执法部门在现场进行快速判断。

润滑油的降解主要是随着自由基的氧化过程进行的。因此，自由基的形成速度和水平提供了一个有益指标，该指标表明了特定的机油在实际驾驶条件下的性能。所以，现在，我们的工作是在典型的驾驶条件下、在机油的使用寿命期间，研究如何使用电子自旋共振波谱仪（ESR，又称EPR）测量自由基的形成。 ESR技术是唯一能够直接测量材料中自由基形成的方法。本文建议确定机油的自由基ESR信号与其驾驶时间是否存在关联。由于自由基是机油中氧化降解的初始产物，因此，能够监测其浓度，将有助于确定特定的机油类型或配方在当前的性能状况。