平台石墨炉原子吸收测磷的方法研究

研究了平台石墨炉原子吸收测定磷的方法,表明以氯化钯和硝酸钙的混合液作为基体改进剂测定生物样品中的磷效果最好,方法特征量为8×10~(-9)g,工作曲线线性范围为0～0.400吸光度,精密度好,抗干扰能力强,方法简单,利用标准曲线即可测定生物样品中磷。     

Establishment and validation of a microfluidic capillary gel electrophoresis platform method for purity analysis of therapeutic monoclonal antibodies

Capillary and microfluidic chip electrophoresis technologies are heavily utilized for development, characterization, release, and stability testing of biopharmaceuticals. Within the biopharmaceutical industry, CE‐SDS and M‐CGE are commonly used for purity determination by separation and quantitation of size‐based variants. M‐CGE is used primarily as an R&D tool for product and process development, while cGMP release and stability testing applications are commonly reserved for CE‐SDS. This paper describes the establishment of an M‐CGE platform method to be used for R&D and cGMP applications, including release and stability testing, for monoclonal antibodies. The M‐CGE platform method enables testing for product development support and cGMP release and stability using the same method, and utilization of one CE technology for the entire lifecycle of a biopharmaceutical product. Critical method parameters were identified, and the analytical design space of those critical parameters was defined using design of experiments (DOE) studies. Once defined through DOE studies, the method design space was validated according to ICH Q2 (R1) guidelines. Additional molecules of the same validated class were verified for use in the method by experimental confirmation of accuracy, specificity, and stability indicating capabilities. The platform method model facilitates rapid utilization of the method in development and GMP testing environments, and eliminates the need for individual validations for assets of the same class entering early stage development.     

高场超导MRI系统铁磁屏蔽的几何优化

磁共振成像（MRI）系统是一种重要的医学影像诊断设备,它根据核磁共振原理对处于静磁场中的人体器官进行成像,具有清晰度高和任意层面成像等优点,在医学检查和诊断方面有着重要的作用,与低场MRI相比,高场MRI系统可提高质子的磁化率,增加图像的信噪比,缩短MRI信号采集时间,从而使脑功能成像的信号变化更为明显;但是较高的背景...     

抗坏血酸基体改进剂平台石墨炉原子吸收光谱法测定蚝油中的铅

本实验建立了以抗坏血酸为基体改进剂测定蚝油中铅的方法。研究了多种基体改进剂消除蚝油基体对测铅的干扰，方法的相对标准偏差为４．９％，回收率为９４％－９６％，检出限为１．５ｎｇ／ｍＬ。本方法可用于蚝油、贻贝油等调味品中铅含量的测定。     

Determination of some refractory elements and Pb by fluorination assisted electrothermal vaporization inductively coupled plasma mass spectrometry with platform and wall vaporization

Platform and wall vaporization for electrothermal vaporization (ETV)-inductively coupled plasma mass spectrometry (ICP-MS) determination of some refractory elements (Ti, V, Cr, Mo, La and Zr) and Pb were comparatively studied with the use of poly (tetrafluoroethylene) (PTFE) as fluorinating reagent. The factors affecting the vaporization behaviors of the target analytes in the platform and tube wall vaporization including vaporization temperature and time, pyrolytic temperature and time were studied in detail, and the flow rates of carrier gas/auxiliary carrier gas, were carefully optimized. Under the optimal conditions, the signal profiles, signal intensity, interferences of coexisting ions and analytical reproducibility for wall and platform vaporization ETV-ICP-MS were compared. It was found that both wall and platform vaporization could give very similar detection limits, but the platform vaporization provided higher signal intensity and better precision for some refractory elements and Pb than the wall vaporization. Especially for La, the signal intensity obtained by platform vaporization was 3 times higher than that obtained by wall vaporization. For platform vaporization ETV-ICP-MS, the limits of detection (LODs) of 0.001 μg L⁻¹ (La) ~ 0.09 μg L^− 1 (Ti) with the relative standard deviations (RSDs) of 1.5% (Pb) ~ 15.5% (Zr) were obtained. While for wall vaporization ETV-ICP-MS, LODs of 0.005 μg L^− 1 (La) ~ 0.4 μg L^− 1 (Pb) with RSDs of 3.2% (Mo) ~ 12.8% (Zr) were obtained. Both platform and tube wall vaporization techniques have been used for slurry sampling fluorination assisted ETV-ICP-MS direct determination of Ti, V, Cr, Mo, La, Zr and Pb in certified reference materials of NIES No. 8 vehicle exhaust particulates and GBW07401 soil, and the analytical results obtained are in good agreement with the certified values.     

横向和纵向加热涂钨平台石墨炉原子吸收光谱法测定镓的比较

分别优化了横向加热和纵向加热涂钨平台石墨炉原子吸收光谱法测定镓的条件。结果显示,纵向加热方式的原子化温度比横向加热低,在灰化温度、进样量、酸介质的影响和化学改进剂等方面,两者没有显著差别。纵向加热的灵敏度高于横向加热,线性范围也比横向加热宽;但是采用横向加热方式能获得更低的检出限和更强的抗干扰能力。     

Contract and product quality in platform selling

More and more e-tailers (platforms) are allowing manufacturers direct access to customers. Two common contracts are offered by platforms to manufacturers: the revenue sharing contract where a platform appropriates a portion of the manufacturer’s revenue, and the fixed fee contract where a platform charges a fixed rent for each sale. Using an analytical model, this paper studies the interrelationship between a platform’s contract choice and a manufacturer’s product quality decision. We find that if product quality is exogenously given, the platform will always adopt the revenue sharing contract. If the manufacturer endogenously decides the quality, however, the platform’s contract choice may be changed. This is because the revenue sharing contract, compared to fixed fee, leads to a lower selling price of the manufacturer, whereas the fixed fee contract can motivate a higher quality than does revenue sharing. As a result, a large (small) market heterogeneity induces the platform to adopt the revenue sharing (fixed fee) contract. We also extend the model to several directions, finding that longer product line, manufacturer competition, lower marginal production cost, and higher platform cost all tend to induce the platform to put forward a fixed fee contract; while if quality decision is less flexible than contract decision, the platform is more ready to embrace revenue sharing. Besides, when there are two platforms competing for the same market, they should differentiate their contract choices so as to mitigate competition.     

用金属钨平台石墨炉原子化器测定环境样品中的锶

使用新原子化器－金属钨平台和全热解石墨管测定环境样品中锶，其优点为：（１）避免锶和石墨管中碳形成化合物，有利提高峰高灵敏度和消除记忆效应。２．避免溶样用的硝酸和高氯酸对石墨管的腐蚀以及产生严重的基体效应，３；空白低。有     

气相色谱仪的两种液体样品自动进样器的兼容设计与研制

设计和构建了多轴多模式、闭环伺服控制系统的研发平台,实现了用于气相色谱仪的不同结构的两种液体自动进样器的并行设计与研制。基于兼容与互换的思路,开发出一体化嵌入式控制驱动模块,采用相同的直流电机、编码器,电气与机械接口统一标准,实现了上述组件在两种机型间的直接代换。研制的标准型110个样品位和平台型40个样品位两种液体自动进样器,与气相色谱仪联机,采用1μL手动进样针,对于0.5μL十六烷-异辛烷标准液体样品,6个不同瓶位连续6次进样测试,重复进样的信号峰面积RSD分别为1.1%和1.5%,取0.1,0.3,0.5,0.7和0.9μL进样,峰面积与进样量的线性相关系数为0.9947。