湖北栀子花挥发油的GC/MS分析

利用水蒸气蒸馏法从湖北栀子花鲜花中提取栀子花挥发油。通过 DB 5弹性石英毛细管柱 GC MS分析所得栀子花挥发油 ,共鉴定了 4 0个化合物并测定了其相对含量。湖北栀子花挥发油的主要成分为芳樟醇 ( 1 7 92 %)、茉莉内酯 ( 9 1 1 %)和惕各酸顺 3 己烯酯( 6 5 4 %)

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.

Tunable liquid crystal lens for a holographic projection system

The tunable liquid crystal (LC) lens designed for a holographic projection system is demonstrated. By using a single patterned electrode LC lens, a solid lens and an encoded Fresnel lens on the LCoS panel, we can maintain the image size of the holographic projector with different wavelengths (λ:674nm, 532nm and 445nm) . The zoom ratio of the holographic projection system depends on the lens power of the solid lens and the tunable lens power of the LC lens. The optical zoom function can help to solve the image size mismatching problem of the holographic projection system. © 2013 SPIE.

Distribution and depuration of the potentially carcinogenic malachite green in tissues of three freshwater farmed Chinese fish with different food habits

The use of malachite green (MG) in fish farming is prohibited in China due to its potentially toxicological and carcinogenic nature, but it is still illegally used in some places. Uptake, accumulation and deputation of MG in various tissues were studied under laboratory conditions in three common freshwater fish, Parabramis pekinensis (plant-eating fish), Carassius auratus (omnivorous fish) and Ophiocephalus argus (carnivorous fish). The concentrations of MG and its primary metabolite, the reduced and colorless leucomalachite green (LMG), were analyzed by liquid chromatography-mass spectrometry (LC-MS2). Absorption of MG occurred during the waterborne exposure and the MG concentrations in gills of the three fish species all showed a maximum at 0 h after an acute water exposure (6 mg l(-1) MG for 20 min). Afterwards, both MG and LMG declined very rapidly in the blood of the fish. Levels of MG and LMG were still above 0.002 mu g g(-1) in fresh weight muscle at 240 h and may persist for as long as 10 days. Most MG was converted rapidly to LMG in the fish and deputation of LMG was very slow in fat tissue. skin and gonads of the fish. Distribution of LMG was strongly dependent on the fat content in the tissues of the fish, but not related to their different feeding habits. Therefore, it appears that fat tissue, skin and gonads of the fish contaminated by MG and LMG pose the greatest risk for human consumption. (C) 2008 Published by Elsevier B.V.

Distribution of microcystins in various organs (heart, liver, intestine, gonad, brain, kidney and lung) of Wistar rat via intravenous injection

The distribution of microcystins (MCs) in various tissues of Wistar rats was studied under laboratory conditions. Rats were injected intravenously (i.v.) with extracted MCs at a dose of 80 mu g MC-LRequivalent/kg body weight. MCs concentrations in various tissues were detected at 1, 2. 4, 6, 12 and 24 h post-injection using liquid chromatography-mass spectrometry (LC-MS). The highest concentration of MCs was found in kidney (0.034-0.295 mu g/g dry weight), followed by lung (0.007-0.067 mu g/g dry weight), stomach (0.010-0.058 mu g/g dry weight) and liver (0.003-0.052 mu g/g dry weight). The maximum MCs content in the whole body of rat, 2.9% of the injected dose, was observed at 2 h post-injection. MCs concentration was higher in kidney than in liver during the experiment, and two peaks of MCs concentration (at 2 and 24 h, respectively) were observed in kidney, indicating that MCs can be excreted directly via kidney of rat. Though heart, intestine, spleen, brain, gonad and stomach contained less than 0.2% of injected MCs during the whole experiment stage, the presence of MCs in these tissues represents potential damage to them. (c) 2008 Elsevier Ltd. All Fights reserved.

Spatial and temporal variations of microcystins in hepatopancreas of a freshwater snail from Lake Taihu

In this paper, spatial and temporal variations of three common microcystins (MC-RR, MC-YR, and MC-LR) in the hepatopancreas of a freshwater snail (Bellamya aeruginosa) were studied monthly in two bays of Lake Taihu. Microcystins (MCs) concentration in hepatopancreas was quantified by liquid chromatography-mass spectrometry (LC-MS). The MCs concentrations in hepatopancreas were higher at Site 1 than those at other sites, which was in agreement with the changes of intracellular MCs concentrations in the water column. There was a significant correlation between MCs concentrations in the hepatopancreas and that in the seston, suggesting that spatial variances of MCs; concentrations in hepatopancreas among the five sites were due to spatial changes of toxic Microcystis cells in the water column. PCCA indicates that in addition to Microcystis, other factors (e.g., water temperature) also substantially affected the accumulation of MCs in hepatopancreas of the snail. (C) 2008 Published by Elsevier Inc.

The accumulation and metabolism of astaxanthin in Scenedesmus obliquus (chlorophyceae)

The biosynthesis and metabolism of astaxanthin in coenobium alga Scenedesmus obliquus were investigated using a two-stage culture. The first stage was for the analysis of biosynthesis and accumulation of astaxanthin in alga cells which were cultured under induction conditions (incubation at 30 degrees C and illumination of 180 mu mol m(-2) s(-1)) for 48 h. The composition of the secondary carotenoids in algal cells was analyzed and seven ketocarotenoids were identified. The results implied that S. obliquus synthesized astaxanthin from beta-carotene through three possible pathways. In the second stage, the cultures were transferred to normal conditions (incubation at 25 C and illumination of 80 mu mol m(-2) s(-1)) for 72 h. Algal cells accumulated more chlorophyll and biosynthesis of secondary carotenoids terminated, the content of secondary carotenoids decreased from 59.48 to 6.57%. The results inferred that accumulation and metabolism of astaxanthin could be controlled by cultivated conditions which also could lead the mobilization of secondary carotenoids to support the algal cell growth. The results also implied that presumed conversions from astaxanthin to lutein or antheraxanthin could be modulated by culturing conditions. (C) 2008 Published by Elsevier Ltd.

Tissue distribution and depuration of the extracted hepatotoxic cyanotoxin microcystins in crucian carp (Carassius carassius) intraperitoneally injected at a sublethal dose

An acute toxicity experiment was conducted by intraperitoneal injection with a sublethal dose of extracted microcystins (MCs), 50 mu g MC-LR (where L = leucine and R = arginine) equivalent/kg body weight (BW), to examine tissue distribution and depuration of MCs in crucian carp (Carassius carassius). Liver to body weight ratio increased at 3, 12, 24, and 48 h postinjection compared with that at 0 h (p < 0.05). MC concentrations in various tissues and aquaria water were analyzed at 1, 3, 12, 24, 48, and 168 h postinjection using liquid chromatography coupled with mass spectrometry (LC-MS). The highest concentration of MCs (MC-RR + MC-LR) was found in blood, 2 -270 ng/g dry weight (DW), followed by heart (3 -100 ng/g DW) and kidney (13 -88 ng/g DW). MC levels were relatively low in liver, gonad, intestine, spleen, and brain. MC contents in gills, gallbladder, and muscle were below the limit of detection. Significant negative correlation was present between MC-RR concentration in blood and that in kidney, confirming that blood was important in the transportation of MC-RR to kidney for excretion. Rapid accumulation and slow degradation of MCs were observed in gonad, liver, intestine, spleen, and brain. Only 0.07% of injected MCs were detected in liver. The recovery of MCs in liver of crucian carp seemed to be dose dependent.

Detection of the hepatotoxic microcystins in 36 kinds of cyanobacteria Spirulina food products in China

Gel filtration chromatography, ultra-filtration, and solid-phase extraction silica gel clean-up were evaluated for their ability to remove microcystins selectively from extracts of cyanobacteria Spirulina samples after using the reversed-phase octadecylsilyl ODS cartridge for subsequent analysis by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The reversed-phase ODS cartridge/silica gel combination were effective and the optimal wash and elution conditions were: H2O (wash), 20% methanol in water (wash), and 90% methanol in water (elution) for the reversed-phase ODS cartridge, followed by 80% methanol in water elution in the silica gel cartridge. The presence of microcystins in 36 kinds of cyanobacteria Spirulina health food samples obtained from various retail outlets in China were detected by LC-MS/MS, and 34 samples (94%) contained microcystins ranging from 2 to 163 ng g(-1) (mean=1427 ng g(-1)), which were significantly lower than microcystins present in blue green alga products previously reported. MC-RR-which contains two molecules of arginine (R)-(in 94.4% samples) was the predominant microcystin, followed by MC-LR-where L is leucine-(30.6%) and MC-YR-where Y is tyrose-(27.8%). The possible potential health risks from chronic exposure to microcystins from contaminated cyanobacteria Spirulina health food should not be ignored, even if the toxin concentrations were low. The method presented herein is proposed to detect microcystins present in commercial cyanobacteria Spirulina samples.

Simultaneous determination of microcystin-LR and its glutathione conjugate in fish tissues by liquid chromatography-tandem mass spectrometry

A sensitive and selective liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous quantitative determination of microcystin-LR (MC-LR) and its glutathione conjugate (MC-LR-GSH) in fish tissues. The analytes were extracted from fish liver and kidney using 0.01 M EDTA-Na-2-5% acetic acid, followed by a solid-phase extraction (SPE) on Oasis HLB and silica cartridges. High-performance liquid chromatography (HPLC) with electrospray ionization mass spectrometry, operating in selected reaction monitoring (SRM) mode, was used to quantify MC-LR and its glutathione conjugate in fish liver and kidney. Recoveries of analytes were assessed at three concentrations (0.2, 1.0, and 5 mu g g(-1) dry weight [DW]) and ranged from 91 to 103% for MC-LR, and from 65.0 to 75.7% for MC-LR-GSH. The assay was linear within the range from 0.02 to 5.0 mu g g(-1) DW, with a limit of quantification (LOQ) of 0.02 mu g g(-1) DW. The limit of detection (LOD) of the method was 0.007 mu g g(-1) DW in both fish liver and kidney. The overall precision was determined on three different days. The values for within- and between-day precision in liver and kidney were within 15%. This method was applied to the identification and quantification of MC-LR and its glutathione conjugate in liver and kidney of fish with acute exposure of MC-LR. (c) 2007 Elsevier B.V. All rights reserved.

Biochemical and ultrastructural changes of the liver and kidney of the phytoplanktivorous silver carp feeding naturally on toxic Microcystis blooms in Taihu Lake, China

Many experimental studies have documented the impact of microcystins (MC) on fish based on either intraperitoneal injection, or oral gavaging via the diet, but few experiments were conducted by MC exposure through natural food uptake in lakes. In this study, the phytoplanktivorous silver carp were stocked in a large pen set in Meiliang Bay of Taihu Lake where toxic Microcystis blooms occurred in the warm seasons. Fish samples were collected monthly and MC concentrations in liver and kidney of the fish were determined by LC-MS. The maximum MC concentrations in liver and kidney were present in July when damages in ultrastructures of the liver and kidney were revealed by electron microscope. In comparison with previous studies on common carp, silver carp showed less damage and presence of lysosome proliferation in liver and kidney. Silver carp might eliminate or lessen cell damage caused by MC through lysosome activation. Recovery in the ultrastructures of liver and kidney after Microcystis blooms was companied with a significant decrease or even disappearance of MC. Catalase and glutathione S-transferase in liver and kidney of silver carp during Microcystis blooms were significantly higher than before and after Microcystis blooms. The high glutathione pool in liver and kidney of silver carp suggests their high resistance to MC exposure. The efficient antioxidant defence may be an important mechanism of phytoplanktivorous fish like silver carp to counteract toxic Microcystis blooms. (C) 2007 Published by Elsevier Ltd.