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1.
用一种简便、快速的前处理和高效液相色谱法(HPLC)对土壤样品中残留的阿特拉津及其主要代谢产物脱乙基阿特拉津、脱异丙基阿特拉津和2-羟基阿特拉津进行定量分析,样品添加回收率因土壤种类和化合物而异:78~121%(阿特拉津、脱乙基阿特拉津、脱异丙基阿特拉津)和40~75%(2-羟基阿特拉津),最小格测浓度为0.005mg/kg;应用气-质联用法(GC/MS)对前三种化合物和脱乙基-脱异丙基阿特拉津进行了定性分析,谱库检索匹配程度达到90%以上。  相似文献   

2.
潘元海  金军  蒋可 《分析化学》2000,28(6):666-671
用反相液谱短柱实现了6种有机磷农药(乙酰甲胺磷、甲基对硫磷、杀螟硫磷、喹硫磷、二嗪农、辛硫磷)的高效液相色谱/大气压化学电离质谱(HPLC/APCIMS)快速分析。此技术可以很好地实现水中痕量有机磷农药的测定,一次联机分析仅需10min。文中还讨论了二嗪农的碰撞诱导解离(CID)碎片谱。二嗪农和喹硫磷的检出限可低达0.09ng和0.1ng。  相似文献   

3.
固相萃取-高效液相色谱-质谱联机在线分析水中痕量除草剂   总被引:29,自引:0,他引:29  
任晋  黄翠玲  赵国栋  蒋可 《分析化学》2001,29(8):876-880
建立了饮用水中痕量除草剂的SPE-LC-MS联机测试方法,该方法仅用45min就可完成水样中7种除草剂(阿特法津,西草净,西码净,杀草净,敌稗,乙草胺,甲磺隆)的分析,检测限低于欧共体所要求的饮用水标准(单种农药浓度小于0.1ug/L)。比起液液萃取,离线SPE等其他前处理方法,在线SPE的结果的重现性和精密度方面大大优于前者,环境水样分析时间大大减少(所需时间为液液萃取的、1/60,离线SPE的1/20),而且更安全性和可靠。我们已在华北某地的地表水和地下水中检测出阿特拉津(1.9ug/L)和乙草胺(1.64ug/L)。  相似文献   

4.
慕卫 《分析化学》1998,26(5):571-573
提出了用高效液相色谱法同时测定土壤中莠去津、氰草津残留量的方法。用甲醇/乙腈提取,石油醚脱脂,中性氧化铝小柱净化,最后用Nova-PakC16柱进行HPLC分析,流动相:甲醇-水(55+45),吸收波长 228 nm,流速0. 7 mL/min.莠去津最低检出限为 0.3 ng,氰草津为0.2 ng。回收率分别为莠去津83.4%~102.3%,氰草津 82.4%~93.5%.  相似文献   

5.
对土壤及玉米植株中均三氮苯类除草剂的残留分析   总被引:4,自引:0,他引:4  
刘峰  慕卫  王金信  于金凤 《色谱》1998,16(6):543-544
土壤或玉米植株样品用V(甲醇)∶V(乙腈)=1∶1提取,提取液用石油醚净化后,浓缩液过C18小柱净化,最后用Nova-PakC18柱进行HPLC分析。回收率:氰草津为82.4%~99.8%,莠去津为85.6%~102.3%,西草净为89.1%~108.4%。  相似文献   

6.
乔雄梧  马利平  H E Hummel 《色谱》1995,13(3):170-173
用一种简便、快速的前处理和高效液相色谱法(HPLC)对土壤样品中残留的阿特拉津及其主要代谢产物脱乙基阿特拉津、脱异丙基阿特拉津和2-羟基阿特拉津进行定量分析,样品添加回收率因土壤种类和化合物而异:78~121%(阿特拉津、脱乙基阿特拉津、脱异丙基阿特拉津)和40~75%(2-羚基阿特拉津),最小检测浓度为0.005mg/kg;应用气-质联用法(GC/MS)对前三种化合物和脱乙基-脱异丙基阿特拉津进行了定性分析,谱库检索匹配程度达到90%以上。  相似文献   

7.
两种氨基酸中[MH-CO2H2]+的特征质谱碎裂   总被引:1,自引:0,他引:1  
运用低能碰撞诱导解离(CID)研究了电子轰击(EI)、快原子轰击(FAB)电离条件下质子化亮氨酸与异亮氨酸解离产生亚稳离子「MH-CO2H2」的单分子质谱破裂,二种异构体呈现出了各自不同的解离特征,根据CID的特征碎片离子和氘代同位素标记实验,提出了其破裂过程的存在离子/中性(碎片)复合物中间体机理,并对有关的特征离子的形成进行了讨论。  相似文献   

8.
应用(EI)MS/Ms法研究了吡啶并苯并蒽酮以及苯并苯并蒽酮类异构体的裂解方式及其与结构之间的相关性,探讨了不同异构体中由M ̄(i+)产生的[M-H]+、[M-HCN]+、[M-COH]+、[M-CO](i+)、[M-(CO+2H)](i+)以及[M-(CO+HCN)](i+)(i=1,2)等1价及2价离子在MS/MS-CID谱上的强度差异和裂解方式,发现是否含有氮原子以及氮原子和苯环位置的差异,是支配这类化合物在CID谱中裂解行为的主要因素。研究结果表明,2价离子的CID谱能更有效地反映这类杂环芳烃异构体之间的结构差异和裂解特性。  相似文献   

9.
以反相高效液相色谱法(RP-HPLC)分离甲硫脑啡肽(MEK)、亮脑啡肽(Leu-ENK)、强啡肽A1-17(DynA1-17)、胆囊收缩素(CCK-8s)。色谱柱为ZORBAXC18(2.1mmID×150mm);流动相:乙腈/水/三氟乙酸(TFA),梯度洗脱,紫外检测器检测:UV215nm。上述条件下,四种神经肽在微克水平得到较好分离。  相似文献   

10.
从邻苯二胺产品中分离出一种白色针状未知化合物,用液相色谱(HPLC)和气相色谱(GC)鉴定其纯度后,同时进行元素、红外光谱(IR)、紫外光谱(UV)、质谱(MS)、核磁共振(NMR)氢谱及碳谱分析。根据分析的结果进行解析,最后确定未知针状不纯物中其主成分为2,1,3-苯并硫咪唑或2,1,3-硫二氮杂茚(C6H4N2S)(2,1,3-benzoth-iadiazole)。  相似文献   

11.
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   

12.
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   

13.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

14.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

15.
Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.  相似文献   

16.
17.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

18.

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.

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19.
The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe2O3. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

20.
Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.  相似文献   

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