氨气敏电极测量水溶液中的氨

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

TOC与COD的测定方法不同。测定COD是采用强氧化剂和加热回流的方法，只能将水中的有机物部分氧化（氧化率较低），并且测定时间较长，即使目前一些快速的

1、恒温槽采用铝块加热的方式，50~200℃范围内进行高精度温度调节。 2、反应柱分为内径3·5·10mmX长度50·100mm的六个种类，材质分为不锈钢材质和玻璃材质，玻璃反应柱适用于酸性样品的反应。 3、反应柱在恒温槽内的固定操作十分简单，只需一个拉杆动作即可完成安装。 4、样品导入端分为液相反应用和气液反应用2个种类（选购） 5、氢气、氧气、二氧化碳气的气体反应用大流量控制单元也可配备（选购）

抗氧化剂是指能防止或延缓食品氧化，提高食品的稳定性和延长贮存期的食品添加剂。GB5009.32-2016《食品安全国家标准 食品中9种抗氧化剂的测定》中采用GPC和C18小柱对食品中9种抗氧化剂进行前处理，该方法回收率低，测试结果不稳定。安谱实验优化了实验方法，用CNW Poly-Sery PSD SPE小柱进行前处理，克服了国标方法的缺点，方法简单，9种抗氧化剂的回收率均在90%以上。