除臭大蒜口服液的GC/MS分析

应用GC/MS联用技术,对除臭大蒜口服液进行了检测,定性鉴定了25种含硫有机化合物。二烯丙基硫醚、甲基烯丙基三硫醚、3-乙烯基-1,2-二硫杂-5-环己烯、2-乙烯基-1,3-二硫杂-5-环己烯和二烯丙基三硫醚是主要组分;二烯丙基四硫醚、烯丙基四硫化氢、2-和3-(2’,3’-二硫杂-5’-己烯基)-3,4-二氢-2H-噻喃、2-(2’-[3’,4’-二氢-2H噻喃基])-1,3-二硫杂-5-环己烯和3-(2’-[3’,4’-二氢-2H-噻喃基])-1,2-二硫杂-5-环己烯是次要组分。最后4种次要组分在

湖泊沉积物中邻苯二甲酸酯类的GC／MS分析

东湖沉积物阴干后用二氯甲烷溶剂萃取，用ＤＢ－５弹性石英毛细管柱ＧＣ／ＭＳ分离鉴定，并结合ｍ／ｚ１４９质量色谱图，确证东湖沉积物中含有９种邻苯二甲酸酯类化合物，它们是邻苯二甲酸二乙酯、二异丁酯、二正丁酯、二己酯、己基辛基酯、二－（２－乙基己基）酯、二辛酯、己基癸基酯和辛基癸基酯，其特征离子及峰度见表１。

自来水中非挥发性氯化产物的GC／MS分析

本文采用ＸＡＤ－２和ＸＡＤ－８（１：１）混合树脂现场富集采样，循环提取器提取，毛细管ＧＣ／ＭＳ定性的方法，通过对冬夏两季的采样分析，初步分析了某地自来（饮用）水中非挥发性有机氯化产物。从夏天自来水中检测出了２８种有机氯化合物。从冬天自来水中只检出了１种有机氯化合物。

湖北大蒜油的GC/MS研究

<正> 1 简介与实验大蒜(Allium sativun L.)系石蒜科葱属植物,世界各地均有栽培,大蒜作为民间药物广泛应用于世界各地。我国用大蒜作为药物有悠久的历史,大蒜在临床上的重要作用引起了广大化学家的重视,对大蒜的分析国内外均有报道。Stoll 等人认为大蒜的主要成分是大蒜辣素(Allicm),其结构式为 CH_2=

珍稀水生动物白暨豚油中脂肪酸的GC/MS分析

白暨豚是一种珍稀水生动物.本文报道了运用 Dexsil-300GC 毛细管柱色质联用仪,对白(?)豚油中脂肪酸进行了分析鉴定,并检测到了22种脂肪酸,其中主要脂肪酸是十四碳烯酸、十六碳烯酸和十八碳烯酸.

Quantitative Determination of Microcystins in Rat Plasma by LC-ESI Tandem MS

A rapid and sensitive method was developed and validated for the determination of MCYST (microcystin)-RR, -LR, and [Dha(7)] MCYST-LR in rat plasma by liquid chromatography-tandem mass spectrometry. The analytes were extracted from rat plasma by protein precipitation, followed by solid-phase extraction. Liquid chromatography with electrospray ionization mass spectrometry, operating in selected reaction monitoring (SRM) mode, was used to quantify MCYST-RR, -LR, and [Dha(7)] MCYST-LR in rat plasma. The recoveries for each analyte in rat plasma ranged from 70.8 to 88.7%. The calibration curve was linear within the range from 0.005 to 1.25 mu g mL(-1). The limit of detection were 1.4, 1.0, 0.6 ng mL(-1) for MCYST-RR, -LR, and [Dha(7)] MCYST-LR. The overall precision was determined on three different days. The values for within- and between-day precision in rat plasma were within 15%. This method was applied to the identification and quantification of microcystins in rat plasma with acute exposure of microcystins via intravenous injection.

Determinations of residual furazolidone and its metabolite, 3-amino-2-oxazolidinone (AOZ), in fish feeds by HPLC-UV and LC-MS/MS, respectively

The antibacterial drug furazolidone belonging to the group of nitrofuran antibacterial agents has been widely used as an antibacterial and antiprotozoal feed additive for poultry, cattle, and farmed fish in China. During application a large proportion of the administered drug may reach the environment directly or via feces. Although the use of furazolidone is prohibited in numerous countries, there are indications of its illegal use. It is known that furazolidone can be rapidly metabolized to 3-amino-2-oxazolidinone (AOZ) in the body of the target organism. In this study, a total of 21 fish feed samples, including 17 commercial fish feeds from local markets in China (representing 15 different formulations) and 4 fish feeds obtained from Germany and Turkey, respectively, are analyzed to determine whether the drug is still illegally used or commercially available feeds are contaminated by this drug. High-performance liquid chromatography (HPLC) and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) methods have been implemented to determine furazolidone and its metabolite AOZ in fish feeds containing animal protein, respectively. An efficient and convenient cleanup method for the determination of furazolidone in fish feeds is developed, and a simple cleanup method for the determination of AOZ is used. Method recoveries for samples used were determined as 87.7-98.3% for furazolidone at two spike levels of 2.0 and 5.0 ng g(-1) and as 95.6-102.8% for AOZ at spike levels of 0.4 and 0.8 ng g(-1). Limits of detections were 0.4 ng g(-1) for furazolidone and 0.05 ng g(-1) for AOZ. The established methods are therefore suitable for the determination of furazolidone and its metabolite AOZ in fish feeds at trace contamination levels. Using the established methods, all fish feed samples have been proved to be furazolidone negative; however, AOZ is tested in 16 of 17 fish feeds obtained from local markets in the Hubei province of China, with a positive rate as high as 94.1%.

An integrated optical receiver in MS/RF CMOS process

A monolithically integrated optoelectronic receiver was realized utilizing a deep sub-micron MS/RF CMOS process. Novel photo-diode with STI and highspeed receiver circuit were designed. This OEIC takes advantage of several new features to improve the performance.

ICP-OES的悬浮进样方式及ICP-MS的碰撞/反应池技术的研究与应用

本论文分为两部分：1. 综述部分（第一章和第二章），评述了悬浮进样方式在电感耦合等离子体发射光谱法（ICP-OES）中的研究与应用；电感耦合等离子体质谱（ICP-MS）中碰撞/反应池技术研究的新进展。2. 实验部分（第三章至第九章），内容包括针对不同性质的样品悬浮液选择适当的稳定剂和悬浮雾化ICP-OES的校准方法研究；以混合碰撞/反应气体解决难度较大的高纯氧化钕中稀土杂质测定的干扰问题；以及浊点萃取-石墨炉原子吸收法测定环境样品中痕量镉、氢化物发生-原子荧光光谱法测定铅基合金中砷和植物样品中锗等实用性强的分析方法研究。 ICP的传统进样方式是将样品转化成水溶液形式，以溶液方式进样。然而大多数样品是以固态形式存在，许多样品相当难溶或难熔。采用直接固体进样方法对这些样品进行分析，是分析工作者追求的目标之一。悬浮液进样是一种固体直接进样方法，除了具有其它固体进样技术的优点外，其最大优点是可以像溶液雾化一样用标准水溶液校准。本研究针对实际分析工作中遇到的具体样品，对悬浮进样ICP-OES技术进行了比较深入的研究，成功解决了样品处理繁琐和样品难以处理等困难。对特殊地质样品和激光晶体材料（Nd:YAG）的悬浮进样分析进行了探索。主要工作为：①建立分析地质样品中主量和微量元素的方法，标准水溶液可以成功地用于校准。优点是可以同时对地质样品中的Si和其它元素进行分析，避免了传统分析时需分别处理样品的麻烦。②探索了分析铌钽矿中铌和钽的应用。由于铌和钽具有强抗化学腐蚀性，所以溶液进样分析时样品处理过程复杂。结果表明，以标准水溶液校准时，只要样品研磨时间延长至5 h，即可获得悬浮进样的满意的回收率。③研究了分析掺钕钇铝石榴石(Nd:YAG)中钕掺杂量的可行性。研究表明，加入适量聚丙烯酸作分散剂并调节pH为6，可以得到稳定悬浮液；以通用标准加入法（GSAM）校准可以得到满意的结果。 我国的稀土资源占世界的80％以上，高纯稀土氧化物是高科技领域中的重要材料。碰撞/反应池技术是目前四极杆ICP-MS消除干扰的先进技术，可以选择性地减少某些基体干扰，使背景和检测限得到显著的改进。本实验选择氧化钕（有7个同位素）作为研究对象，采用碰撞/反应池技术重点解决四极杆ICP-MS方法对高纯Nd2O3中稀土杂质进行测定时，基体Nd对Tb、Dy和Ho严重的氧化物或氢氧化物干扰难题。研究结果如下：①在四极杆高分辨率模式下，可以消除Nd对Pr的相邻峰的拖尾干扰；②采用碰撞/反应池技术，设计了10% O2-10% Ar-80% He混合气体作为碰撞/反应气，将Tb、Dy和Ho分别转化为相应的氧化物离子进行测定，成功地消除了基体Nd对Ho的干扰；Nd对Tb和Dy造成干扰的表观浓度显著降低。本方法可直接测定纯度为6N的高纯Nd2O3中的Ho；对纯度为6N的高纯Nd2O3中的Tb和Dy进行扣除，可以分析纯度达5N的高纯Nd2O3中的Tb和Dy。与文献报道的其它消除基体Nd干扰的方法相比较，此方法能够对纯度更高的Nd2O3进行直接分析，且操作简便。此方法也可进一步拓宽，有望解决其它轻稀土氧化物对中重稀土检测的质谱干扰问题。 论文的7～9章的工作包括：浊点萃取-GFAAS测定环境样品中痕量镉、HG-AFS分析铅基合金中砷和植物样品中锗的研究。针对实际分析工作中的具体困难，以上工作分别解决了分析元素含量低、测定干扰严重及样品处理的问题，建立了实用性强、准确度高的分析方法，具有实际应用价值。

A 10-bit 50-MS/s sample-and-hold circuit with low distortion sampling switches

A fully-differential switched-capacitor sample-and-hold (S/H) circuit used in a 10-bit 50-MS/s pipeline analog-to-digital converter (ADC) was designed and fabricated using a 0.35-μm CMOS process. Capacitor fliparound architecture was used in the S/H circuit to lower the power consumption. In addition, a gain-boosted operational transconductance amplifier (OTA) was designed with a DC gain of 94 dB and a unit gain bandwidth of 460 MHz at a phase margin of 63 degree, which matches the S/H circuit. A novel double-side bootstrapped switch was used, improving the precision of the whole circuit. The measured results have shown that the S/H circuit reaches a spurious free dynamic range (SFDR) of 67 dB and a signal-to-noise ratio (SNR) of 62.1 dB for a 2.5 MHz input signal with 50 MS/s sampling rate. The 0.12 mm~2 S/H circuit operates from a 3.3 V supply and consumes 13.6 mW.

MS/RF CMOS工艺兼容的光电探测器模拟与测试

设计了一种新型的与MS/RF CMOS工艺全兼容、带深n阱(DNW)、浅沟槽隔离(STI)的双光电探测器,分析了其工作机理,用器件模拟软件ATLAS对其暗电流、响应电流、光调制频率响应和波长响应进行了模拟.采用TSMC 0.18 μm MS/RF CMOS工艺进行了流片,对芯片进行了暗电流和响应度的测试.模拟和测试结果均表明,该探测器与常规双光电探测器相比,具有较低的暗电流和较高的响应度.

Monolithically Integrated Optoelectronic Receivers Implemented in 0. 25μm MS/RF CMOS

A monolithically integrated optoelectronic receiver is presented. A silicon-based photo-diode and receiver circuits are integrated on identical substrates in order to eliminate the parasitics induced by hybrid packaging. Implemented in the present deep sub-micron MS/RF （mixed signal, radio frequency） CMOS,this monolithically OEIC takes advantage of several new features to improve the performance of the photo-diode and eventually the whole OEIC.