沉积物中7种指示性多氯联苯含量的分析

本文采用ASE提取、酸性硅胶净化、GCMS法测定河流沉积物中7种指示性多氯联苯(PCB)单体的残留.检测结果表明,方法检出限为0.13～0.39ng·g-1、基体加标回收率在78.5%～102%之间、重复测定相对标准偏差在1.6%～6.6%.沉积物中7种PCB总量变化是n.d.～6.09ng·g-1.     

Analysis of Biodiesel Feedstock Using GCMS and Unsupervised Chemometric Methods

Various biodiesel feedstocks were evaluated using gas chromatography–mass spectrometry data combined with unsupervised chemometric methods of analysis. Peak areas of the fatty acid methyl esters (FAMEs) present in the biodiesel feedstocks (soybean oil, canola oil, waste grease, animal tallow, etc.) were utilized. The importance of chromatographic parameters, such as temperature program and column polarity, was examined with respect to the clustering that was observed using principal component analysis (PCA) and hierarchical cluster analysis (HCA). Biodiesels in this study clustered based on feedstock type regardless of temperature program or column type, as long as FAME isomers were resolved from one another. As such, the number and type of FAME components required to observe this clustering was investigated further. In general, the minor components in the sample did not provide improved clustering and thus did not need to be included. In addition, data from various temperature programs or column types were combined to yield similar clustering, showing potential versatility in analyzing similar samples across laboratories using different columns and column properties. Overall, we determined that (1) minor FAME components are non-essential for feedstock identification and (2) PCA and HCA clustering is based on feedstock, regardless of column selection, so long as resolution of FAME isomers is achieved.     

复合肥生产中有机污染气体的气相色谱/质谱分析

利用活性炭纤维的强吸附力,对生产有和合肥过程中产生的有机污染废气进行采样、溶剂解吸和GC—MS分析。共分离和鉴定了67个化合物,主要产生的化合物为烷烃类31个,芳香族类19个,酯类化合物9个等。     

Sol–Gel Pd Exhaust Catalysts and Hydrocarbon Speciation

Sol–gel Pd/alumina promoted by oxygen-storing CeO₂ or CeO₂–Tb₄O₇ catalysts has higher hydrocarbon oxidation activity than commercial three-way catalysts. It is active in hydrocarbon (and CO) oxidation even under net reducing conditions albeit over short periods of time. This observation is relevant to cold start conditions. Cryo-focussing GCMS and pulse RGA experiments suggest that mechanistically interesting by-product hydrocarbon species evolve from the catalysts under just these conditions, even when the fuel is LPG in type. Further catalyst developments and analytical refinements are likely to go hand in hand as the mode of operation of these environmental catalysts is better understood from their by-product fingerprint.     

GC-MS法测定大花红景天中大花红天素含量

利用气相色谱-质谱(GC-MS)法测定大花红景天中的大花红景天素含量。样品中的大花红天素经水提取,大孔树脂柱净化、分离。根据MS的定性结果,强峰m/z 69为大花红天素的特征离子峰,利用选择性离子扫描方式(SIM)进行定量分析。实验结果表明:方法回收率在93.70%～98.58%,变异系数为1.23%～2.94%,线性范围在0.10～0.50 mg/ml,检出限(3S/N)为0.01 mg/mL,该分析方法具有准确度高、选择性好、线性范围宽、干扰少等特点,适合大花红景天中大花红天素的定量测定。     

基于Windows操作系统的智能建筑物综合布线管理系统的设计与实现

综合布线系统是智能化建筑中的重要组成部分,采用传统的人工管理方式很难对其进行有效的管理。本文结合智能建筑管理系统（IBMS）的组成,给出了智能建筑中综合布线管理系统的设计方法,并对该系统的各管理模块进行了详细划分。