紫外分光光度法测定人参及三七中总皂苷含量

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

从中药中提取分离化合物，第一步需要将中药材中的成分用有机溶剂提取出来，包括常规的有机溶剂浸泡，超声提取，超临界提取和加速溶剂萃取（Aseeker-600型加速溶剂萃取仪）等，得到一份总提物。

矿物油组成中的共轭体系物质在紫外光区有较强的吸收，依据朗博 - 比尔定律，在256nm紫外光波长，可测定油样的吸光度来确定相应油的量。 由于紫外光度法对于油种的敏感性较强，本方法的油样需采用标准物质。