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1.
本文建立了固相萃取-气相色谱法定量分析地下水中酞酸酯类(PAEs)有机污染物的方法。利用正交试验和单因素实验对影响回收率的4个主要因素(洗脱溶剂种类、水样体积、洗脱溶剂体积、固相萃取小柱填料量)进行了萃取条件的优化。综合考虑各方面因素后确定的最佳萃取条件为:二氯甲烷和丙酮为洗脱剂,体积8mL、0.5L水样、柱填料500mg。方法线性范围0.05~10.00μg/L,检出限0.05~0.341ng/L,相对标准偏差0.038%~1.107%。该方法应用于江汉平原地下水中PAEs测定,取得满意结果。  相似文献   

2.
高效液相色谱-质谱法分析测定水中氨基甲酸酯   总被引:20,自引:0,他引:20  
采用固相萃取-高效液相色谱-质谱法(LC/MS)检测研究了水中氨基甲酸酯农药残留。水样用固相萃取富集净化,环己烷+乙酸乙酯(1+1)洗脱;以甲醇-10mmol/L乙酸铵为梯度流动相,Symmetry C18柱高效液相色谱分离。电喷雾正离子模式,选择质子化氨基甲酸酯分子离子[M+H]^+为定量离子进行MS测定。结果表明,6种氨基甲酸酯组分的平均加标回收率为73.5%~89.8%;相对标准偏差为4.50%~12.6%;水样浓缩至1/2500后的检出限为0.8~3.2ng/L。本法具有非常高的选择性、灵敏度和准确度,完全能满足水中痕量氨基甲酸酯农残的高灵敏分析。  相似文献   

3.
采用同位素稀释法结合固相萃取净化,建立了海产品中苯并(α)芘残留的气相色谱串联质谱(6C—MS/MS)检测方法。样品经乙腈一丙酮(体积比6:4)溶液提取,硅胶固相萃取净化,苯并(μ)芘用GC—MS/MS测定,同位素D12-苯并芘内标法定量。方法的平均回收率为93%-98%,相对标准偏差为6.2%~12.2%(n=6),定量限为0.2μg/kg。用该方法测定FAPAS烟熏鱼有证标准样品,测定值与标准值一致。  相似文献   

4.
用直接进样、固相萃取进样和自制的固相微萃取(SPME)装置进样与气相色谱(GC)及GC—MS联用检测了室内空气中的挥发性有机污染物,对影响SPME操作条件进行了优化。使用的方法在所测范围内具有良好的线性(相关系数为0.968~0.991),检出限达0.3—2、3μg/L,相对标准偏差均小于7%,回收牢为95%~111%。结果表明:自制的SPME装置操作简单、快速、安全,准确度、灵敏度优于其它两种方法。  相似文献   

5.
我国环境中有机污染物分析方法及痕量富集技术的进展   总被引:1,自引:0,他引:1  
对有机污染物分析在近年进展作了评述。其主要内容涉及试样的预处理技术(如顶空法,吹扫-捕集法,固相萃取,半透膜等技术),各化合物的适用及有效的分析方法或仪器(如GC,HPLC及GC/MS等)以及各种技术及方法的联用技术等(引述文献37篇)。  相似文献   

6.
利用C18固相萃取膜与气质联用(GC-MS)技术建立了瓶装饮用水中27种痕量化合物多残留同时检测的方法.水中被测物多残留通过C18固相萃取膜富集,丙酮洗脱,旋转蒸发与吹氮浓缩,GC/MS选择离子监测模式(SIM)测定.被测物加标回收率在60%~120%之间,相对标准偏差小于25%.  相似文献   

7.
水中有机污染物前处理方法进展   总被引:15,自引:4,他引:15  
综述了水样中有机污染物前处理方法的进展情况;重点介绍液-液萃取、固相萃取、液相微萃取、膜萃取和顶空处理技术5种前处理方法的一些基本情况及其优缺点。  相似文献   

8.
多壁纳米碳管固相萃取测定水中的有机氯农药   总被引:7,自引:3,他引:7  
对于水样中的有机氯农药的净化方法主要是采用传统的液液分配的方法,缺点是溶剂使用量和前处理复杂。近年来固相萃取及固相微萃取等技术被应用到水样中的有机污染物的测定。如利用键合在硅胶上的非极性(C18,LC18等)或极性物质(LC-CN,LC-NH2)对水中有机物进行富集,用GDX或XAD自填的固相柱的报道也很多。纳米技术和纳米材料的发展为开发固相萃取材料带来新契机。纳米材料是指尺寸大小在从1~100m之间物质。与普通的块体材料相比,纳米材料具有较大的比表面,因而有可能具有较大吸附容量。纳米材料在环境有机污染物分离富集方面的应用研究才刚刚开始。本文主要就纳米碳管对水样中的有机氯农药进行研究,优化固相萃取条件。  相似文献   

9.
建立了顶空固相微萃取(HSSPME)-气相色谱(GC)-质谱(MS)联用测定纺织品中甲苯、4-乙烯基环己烯、苯乙烯、萘和1-苯基环己烯5种挥发性有机物(VOCs)的分析方法。选择聚二甲基硅氧烷(PDMS)作为萃取涂层,优化了SPME的萃取条件,包括平衡时间、萃取时间、萃取温度、顶空体积、离子强度、搅拌速度、解吸温度和时间以及GC—MS仪器条件。对于甲苯、4-乙烯基环己烯、苯乙烯、萘和1-苯基环己烯方法线性范围分别为0.087~870、3.32~3320、2.28~2280、0.015~150和0.050~50.0ng/g;检出限分别为0.005、0.042、0.670、0.008和0.011ng/g。实际样品加标回收率在80.1%~122%之间,RSD在0.8%~8.6%之间。方法符合纺织品中痕量VOCs的快速分析要求。  相似文献   

10.
固相萃取-GC/MS法测定水样中20种有机氯农药   总被引:2,自引:0,他引:2  
建立了用固相萃取小柱提取和净化、GC/MS定性定量同时测定水样中20种有机氯农药的方法。方法采用OasisHLB固相萃取小柱萃取富集水样,二氯甲烷洗脱,加入菲-d10作为内标,利用GC/MS进行定性定量,步骤简便,线性响应良好,干扰小,方法检出限为0.21~0.72 ng/L(按水样1L计),加标回收率为64.8%~122%,RSD为1.2%~11.0 %。成功利用该方法对广西实际河水样品进行了检测。结果表明方法可以同时满足环境水样中20种痕量有机氯农药的测定。  相似文献   

11.
利用手持技术改进测定乙醇分子结构实验   总被引:1,自引:0,他引:1  
利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。  相似文献   

12.
The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.  相似文献   

13.
14.
由于石化行业的生产需要,其材质的使用具有多样性和广泛性,经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识,根据光谱仪的测试能力及标样的采集,实现了一个或几个元素测量范围的扩展,并对其测量的影响因素进行了研究。  相似文献   

15.
The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.  相似文献   

16.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

17.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

18.
实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。  相似文献   

19.
Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.  相似文献   

20.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

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