2018国家食品安全抽检实施细则 GB方法配置方案

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

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。

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。

Thermo Scientific针对空气敏感样品开发了惰性气体/真空保护样品传输系统CleanConnect，为空气敏感材料表征开拓出了全新视野。惰性气体/真空保护样品转移工作流程能够帮助科研工作者拓展空气敏感材料的研究边界，探究更多未知领域。