QuEChERS AOAC 方法用于茄子中农药多残留的检测

YSI 防玷污的10点技巧 随着电子技术的进步、电源管理的改进和电池寿命的延长，生物玷污成为目前决定监测仪器投放周期长度的决定因素，特别是应用于长期、连续监测。应用一些防玷污技术可以延长仪器的维护间隔，能够减少野外的仪器维护的次数，并提高水质监测数据精度。 防玷污技巧的详细内容请参考文章《YSI 防玷污的10点技巧》

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

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。

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。