昆虫触角电位(EAG)及其与气谱联用(GC-EAD)技术

昆虫触角电位(EAG)和气相色谱-触角电位(GC-EAD)是昆虫化学生态学中最重要的电生理技术,在研究昆虫对信息化学物质的感受机理、筛选活性信息素成分或植物次生物质等方面发挥关键作用。本文介绍这两种技术的基本原理、操作步骤和应用实例等,并对使用中应该注意的事项进行了详尽讨论。     

昆虫神经生物学研究技术:触角电位图记录

触角电位图记录是昆虫神经生物学中用于昆虫嗅觉、信息素生物测定研究的重要技术之一。该技术具有敏感性、选择性高及操作简单易行等优点。该文以荷兰Syntech公司的产品为例详细介绍了此技术原理、装置、操作及应用     

改进蝇类昆虫触角电位技术的尝试

本文通过对美洲斑潜蝇触角的扫描电镜观察及触角电位的测定 ,提出对蝇类昆虫触角电位测定技术的改进方法 :将触角芒切断 ,露出血淋巴 ,记录电极与触角芒的断面相接 ,参照电极通过头孔插入脑血腔形成回路。     

气相色谱—质谱联用技术在植物激素分析中的应用

本文结合自己多年来工作的体会介绍了GC—MS技术如何用于植物激素分析和在分析过程中应注意的关键技术问题。     

松毛虫性信息素的固相微萃取及质谱和触角电位分析

松毛虫性信息素成分在腺体中含量很低。本研究利用固相微萃取（SPME）技术近距离长时间采集单头云南松毛虫Dendrolimus houi处女雌蛾释放的性信息素成分, 并进一步利用气相色谱-质谱（GC-MS）和气相色谱-触角电位联用（GC-EAD）技术分析SPME采集的性信息素成分。 结果显示: 在云南松毛虫处女雌蛾求偶召唤期间SPME聚乙二醇/二乙烯基苯（CAR/DVB）萃取头吸附了大量的反5, 顺7-十二碳二烯醇（E5, Z7-12:OH）和反5, 顺7-十二碳二烯乙酸酯（E5, Z7-12:OAc）成分及微量的反5, 顺7-十二碳二烯醛（E5, Z7-12:Ald）成分, 这3种腺体成分均能激起云南松毛虫雄虫触角电位反应。与溶剂浸提昆虫性信息素成分的方法比较, SPME活体采样技术和GC-MS及GC-EAD分析方法联用研究昆虫的信息素成分具有采集的样品代表性强、样品量能满足色谱分析需要和无溶剂干扰等方面的优点。最后还着重讨论了SPME技术的应用价值、效果及实际应用中应该注意的一些问题。      

长足大竹象的触角超微结构和对竹笋挥发物的触角电位反应

长足大竹象Cyrtotrachelus buqueti Guerin-Meneville是当前竹林主要害虫, 专一地取食危害丛生竹笋梢。本研究应用电镜扫描、气质色谱联用(GC-MS)及触角电位(EAG)技术, 分析了长足大竹象成虫触角的超微结构、不同竹笋挥发物的成分及其与成虫的触角电位反应, 以期分析长足大竹象寡食竹笋的原因。结果表明长足大竹象成虫触角上感知竹笋挥发物的锥形感器数量最多、密度最大。气质色谱联用在竹笋挥发性物质中检测到28种物质, 醛类物质相对含量最高, 其次是醇类和酸类物质。EAG分析表明苯甲醛等13种竹笋挥发物的相对触角电位值显著高于对照, 以苯甲醛的EAG值最高。结果提示丛生竹笋梢高含量和特有的挥发物成分可能是吸引长足大竹象取食竹笋的重要物质, 长足大竹象对竹笋气味的识别很大可能是根据以苯甲醛为主要成分组成的、具有特定成分比例的化学指纹图谱。本研究为研制长足大竹象取食引诱剂提供了理论依据。     

气相色谱-质谱联用技术及其在代谢组学中的应用

代谢组学是以高通量、高灵敏度、高分辨率的现代仪器分析方法为手段,对细胞、体液、组织中所有代谢物进行无偏向的定性与定量分析的一门学科。气相色谱-质谱联用技术具有较高的检测灵敏度和鉴定准确度,通过标准谱图库的比对可对代谢物进行快速的鉴定,因此被广泛应用于生物样品的代谢产物的检测中。文中对近年来气相色谱-质谱联用技术的发展以及在代谢组学研究中取得的成果进行了综述。首先介绍了气相色谱-质谱联用技术的分类和常用的样品衍生化方法;继而从样品预处理、定性与定量分析、数据分析三方面介绍了气相色谱-质谱联用技术分析代谢物的方法,并系统地对该技术在微生物、植物、疾病诊断领域的应用实例进行了评述;最后提出了当前气相色谱-质谱联用技术在代谢组学研究中存在的问题并对后续的研究进行了展望。     

沙葱萤叶甲成虫触角感器超微结构及对沙葱挥发物的触角电位反应

【目的】明确沙葱萤叶甲Galeruca daurica成虫触角感器类型及对寄主植物挥发物的电生理反应,为进一步研究沙葱萤叶甲的化学感受机理奠定基础。【方法】使用扫描电子显微镜观察沙葱萤叶甲成虫触角上的感器类型;采用顶空动态吸附收集法采集寄主植物沙葱Allium mongolium的挥发物,利用气质联用仪测定沙葱主要挥发物组分,并利用触角电位技术(electroantennogram, EAG)测定沙葱萤叶甲成虫对这一寄主植物主要挥发物成分的电生理反应。【结果】沙葱萤叶甲成虫触角上分布的感器主要有5种类型,分别是毛形感器(sensilla trichodea, ST)、刺形感器(sensilla chaetica, SC)、锥形感器(sensilla basiconica, SB)、钟形感器(sensilla campaniformia, SCa)和B9hm氏鬃毛(B9hm bristles, BB)。沙葱挥发物主要由32种化合物组成,其中,含硫化合物占总量的49.3%。雌成虫对二烯丙基硫醚、二烯丙基二硫、顺-2-己烯-1-醇、2-己烯醛、苯甲酸甲酯和己醛6种化合物表现出较强的触角电位反...     

不同危害状态下寄主萜烯挥发物含量的变化及松墨天牛对其组分的触角电位反应

用气相色谱-质谱（GC-MS）联用法对5种生理状态（健康、人为物理损伤、饵木、取食和产卵）的马尾松Pinus massoniana和取食危害状态的雪松Cedrus deodara的萜烯进行分析。研究结果显示,5种生理状态下,α-蒎烯在萜烯组分中均占有最高比例。健康状态下马尾松树干和树枝中的萜烯组分不同且含量有显著差异。随着饵木的衰弱进程,α-蒎烯的相对含量显著减少,β-蒎烯的含量显著增加,我们推测,α-蒎烯与β-蒎烯的相对比例越小则寄主树势衰弱的程度越深,其两者比例的变化是马尾松寄主树势衰弱程度变化的一个重要信号。人为物理损伤的马尾松树干与树枝的α-蒎烯、β-蒎烯和β-水芹烯含量差异显著。不同产卵危害程度的马尾松树干萜烯类组分不同,同一产卵危害程度的马尾松树干上部和下部的多数萜烯组分相对含量差异显著,但变化无明显规律。取食危害状态下马尾松和雪松萜烯种类不同且含量差异显著。重度产卵危害马尾松树干与取食危害树枝萜烯中,α-蒎烯、β-蒎烯、柠檬烯和β-水芹烯相对含量差异显著。第13天的饵木与人为物理损伤的马尾松树干的萜烯中,饵木的β-蒎烯和柠檬烯相对百分含量均比人为物理损伤状态的高,而α-蒎烯则相反。α-蒎烯和β-蒎烯在取食危害树枝中的含量显著高于健康树枝,而β-月桂烯、β水芹烯和反式石竹烯在健康状态树枝中的含量显著高于取食危害树枝。除了α-蒎烯和β蒎烯,健康状态与产卵危害状态的马尾松树干萜烯相对含量大都差异显著。α-蒎烯,β-蒎烯和β-水芹烯在人为物理损伤与虫害状态的马尾松树干及树枝中含量差异较大。总之,α-蒎烯、β-蒎烯和β-水芹烯很可能是影响和调节松墨天牛取食和产卵行为最为重要的信号物质。松墨天牛Monochamus alternatus Hope对寄主萜烯的触角电位（EAG）表明,该天牛对β-蒎烯的EAG活性高于其他萜烯,乙醇也能引起较高的EAG反应活性,但总体上对单一萜烯的EAG反应活性不强,且存在雌雄差异。     

棉铃虫对几种信息化合物的触角电位 (EAG)反应

通过棉铃虫成虫对 1 0种寄主植物挥发性物质、两种性信息素组分及两者的混合作用的触角电位反应 ( EAG) ,发现棉铃虫雌雄蛾对 1 0种挥发性物质的 EAG反应差异显著 ( P<0 .0 5 ) ,说明了 1 0种挥发物质对棉铃虫成虫的感应功能有所不同。 1 0种寄主植物挥发物质与性信息素主要组分混合后能引起雄蛾 EAG反应明显高于单独性信息素的反应 ,其中有 4种挥发性物质明显地增强棉铃虫对性信息素的反应 ( P<0 .0 5 ) ,即庚醛、1 -己醇、反 - 2 -己烯醇、顺 - 3-己醇 - 1 ,说明了以寄主植物挥发物质与昆虫性信息素混合作用来增强昆虫性信息素的应用效果。不同光温条件下饲养的雄蛾对寄主植物挥发性物质与性信息素相互作用的 EAG反应差异显著 ( P<0 .0 5 )。     

Assay for beta-glucuronidase utilizing headspace gas chromatography

An assay for beta-glucuronidase is described. The assay uses 1-(beta-D-glucopyranuronosyl)pyridinium hydroxide, inner salt, as substrate and the quantitative determination is performed with headspace gas chromatography, measuring one of the products, pyridine, in the gas phase. The assay has been developed utilizing commercially available beta-glucuronidase (EC 3.2.1.31.) from Escherichia coli, and has been applied to various sources of beta-glucuronidase. Crude homogenates can be assayed directly with a minimum of manipulative steps and the method is suited for automation.     

Analysis of picogram quantities of indole-3-acetic acid by gas chromatography with fused silica column and flameless nitrogen selective detector

Use of a gas chromatograph equipped with a fused silica capillary column and a nitrogen-phosphorus detector permits selective detection of indole-3-acetic acid and other indoles at the low picogram level. The applicability of the method is demonstrated by the analysis of endogenous indole-3-acetic acid from shoots of Salix pentandra L.     

气相色谱法测定啤酒中的游离脂肪酸

气相色谱法测定啤酒中辛酸到二十二碳酸共１１种游离脂肪酸,采用多级溶剂萃取及薄层色谱纯化技术进行样品制备,并采充氮措施抑制脂肪酸的氧化产生,此方法有较好的重复性和回收率。     

Determination of 1-aminocyclopropane-1-carboxylic acid (ACC) in leaf tissue and xylem sap using capillary column gas chromatography and a nitrogen/phosphorus detector

The Lizada and Yang method, commonly used for analyzing 1-aminocyclopropane-1-carboxylic acid (ACC), the immediate precursor of the plant hormone ethylene, is subject to interference and lacks internal standards. The use of combined gas chromatography-mass spectrometry (GC-MS) overcomes these shortcomings but the method is expensive and unavailable to many laboratories. We describe an alternative physico-chemical method using a capillary column gas chromatograph fitted with a standard nitrogen/phosphorus detector. After forming the N-benzoyl n-propyl derivative, measurements of ACC concentrations in extracts of leaves and in xylem sap of tomato plants using the nitrogen/phosphorus detector were within 10% of those obtained by GC-MS. Concentrations in plants grown in well-drained soil were approximately 0.16 nmol g^–1 fresh weight (leaves) and 0.04–0.01 mmol m^–3 (sap). Flooding the soil for 48–72 h increased these values approximately 9-fold.     

Measuring residual solvents in pharmaceutical samples using fast gas chromatography techniques

Residual process solvents in pharmaceutical samples are monitored using gas chromatography (GC) with either flame ionization detection (FID) or mass spectrometry. Based on good manufacturing practices, measuring residual solvents is mandatory for the release testing of all active pharmaceutical ingredients and is routinely performed on samples of process intermediates. General GC methods have been developed to monitor solvents routinely used in the drug synthesis process. It is now possible to take advantage of GC equipment with faster temperature ramping capabilities, in combination with shorter capillary GC columns, to achieve a considerable gain in efficiency and a reduction in analysis turnaround time. In this paper, the development and implementation of fast GC methods for residual solvents testing will be discussed. Continued efforts to improve the efficiency of gas chromatography using existing technologies such as, the ThermoOrion Flash GC will also be discussed.     

One-pot microwave derivatization of target compounds relevant to metabolomics with comprehensive two-dimensional gas chromatography

Metabolomics has been defined as the quantitative measurement of all low molecular weight metabolites (sugars, amino acids, organic acids, fatty acids and others) in an organism's cells at a specified time under specific environmental/biological conditions. Currently, there is considerable interest in developing a single method of derivatization and separation that satisfies the needs for metabolite analysis while recognizing the many chemical classes that constitute the metabolome. Chemical derivatization considerably increases the sensitivity and specificity of gas chromatography–mass spectrometry for compounds that are polar and have derivatizable groups. Microwave-assisted derivatization (MAD) of a set of standards spanning a wide range of metabolites of interest demonstrates the potential of MAD for metabolic profiling. A final protocol of 150 W power for 90 s was selected as the derivatization condition, based upon the study of each chemical class. A study of the generation of partially derivatized components established the conditions where this could potentially be a problem; the use of greater volumes of reagent ensured this would not arise. All compounds analyzed by comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry in a standard mixture showed good area ratio reproducibility against a naphthalene internal standard (RSD < 10% in all but one case). Concentrations tested ranged from 1 μg/mL to 1000 μg/mL, and the calibration curves for the standard mixtures were satisfactory with regression coefficients generally better than 0.998. The application to gas chromatography–quadrupole mass spectrometry and comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry for a typical reference standard of relevance to metabolomics is demonstrated.     

The degree of acetylation of chitins by gas chromatography and infrared spectroscopy

Gas chromatography of a number of amines, alcohols and sulfur derivatives was carried out on chitin and partially deacetylated chitins as well as on chitosan. The retention time of methanol is proportional to the degree of acetylation, and therefore a method is proposed for the gas-chromatographic determination of the degree of acetylation of chitin/chitosan. The analysis of the infrared spectra of chitin/chitosan also permits one to determine the degree of acetylation by using the ratio of the bands 1550 and 2878 cm^?1.     

利用乙腈作为内标气相色谱法快速测定发酵液中的乳酸

建立了一种内标法准确、快速测定发酵液中乳酸含量的方法。色谱柱为2m×3mm(i.d.),内填GDX-103的不锈钢柱,FID检测器。内标为1.0%的乙腈溶液。实验结果表明,该方法的相对标准偏差小于1.0%(n=7),回收率在99%以上。方法具有前处理简单、干扰小、灵敏度高、分析速度快,线性测定范围宽等优点。     

Recovery of volatile fatty acids from biological materials for direct analysis by gas chromatography

A simple and efficient methodology for preparing aqueous extracts of volatile fatty acids from biological materials, for direct analysis by gas chromatography is described. Peak areas and responses relative to n-butyric acid were used to calculate concentrations of the individual acids. An example is given for analysis of the volatile fatty acids found in the blood of the lugworm Aerinocola marina.     

Estimation of ethanol in fermentation broth by solvent extraction and gas chromatography

Ethanol from fermentation is usually estimated by gas chromatography after centrifuging or distilling the broth. In this paper a more efficient and rapid method is described in which ethanol is extracted by an organic solvent such as n-butanol and the extract is analysed by gas chromatography. The distribution factor determined has a value close to unity and is dependent on ethanol concentration, but independent of sugar concentration.