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1.
用HPLC法测定五氯硝基苯和多菌灵的复配制剂   总被引:4,自引:2,他引:2  
采用HPHypersilC18色谱柱,甲醇和水梯度洗脱,用二极管矩阵检测(254nm)的HPLC法,12min内同时测定了五氯硝基苯-多菌灵可湿性粉剂中2种有效成分的含量。该法简便、快速、准确,标准偏差分别为0.12%和0.15%,相对标准偏差分别为0.46%和1.44%。  相似文献   

2.
染毒粮食中7种化学战剂的气相色谱分析方法   总被引:5,自引:0,他引:5  
冯翠玲  周永新  胡绪英 《分析化学》2000,28(10):1245-1247
为了研究染毒粮食(大米、面粉)中7种化学战剂的检测方法,建立了相应的气相色谱分析方法。该法采用火焰光度检测器检测,BP-10毛细管色谱柱分离,二氯甲烷萃取。模拟染毒大米、面粉中化学战剂测定相对误差为2.0%~12.0%、8.10%~27.3%。相对标准偏差分别为0.9%~6.10%、3.95%~16.8%。方法的最低检出浓度为0.01~2μg/g。所建方法操作简便,灵敏度高。  相似文献   

3.
比值导数紫外吸收光谱法测定阿司匹林中的微量水杨酸   总被引:8,自引:0,他引:8  
本文应用比值导数吸收光谱法于药物阿司匹林中微量水杨酸含量的测定,在0.01 ̄0.12%浓度范围内比值导数光谱峰高与水杨酸浓度成正比。线性相关系数为0.9994,检出限为0.005%,样品测定回收率为95.0% ̄102.5%。将其用于阿司匹林原料中微量水杨酸杂质含量的测定,乙酰水杨酸含量在90.0% ̄99.0%范围内,不干扰微量水杨酸的测定。  相似文献   

4.
用含10%聚酰胺的修饰碳糊电极研究了测定色氨酸和酪氨酸的伏安法,发现在0.2mol/L盐酸-醋酸钠底液中色氨酸和酪氨酸有良好的氧化峰响应。结合2.5次微分技术,两种氨基酸的检测浓度线性范围良好。色氨酸和酪氨酸的相对标准偏差分别为5.2%和7.0%,检测限分别为0.024μmol/L和0.034μmol/L。检测特性经统计秀较大的改善。文中对电极过程进行讨论。  相似文献   

5.
报道了血中敌鼠、氯敌鼠、杀鼠酮的题示测定方法。该法操作简便快速、回收率高,灵敏度较高,萃取使用国产高分子多孔微球GDX301,价廉易得。三种杀鼠剂以10mg/L量分别加于血中,回收率依次为100.5%±2.9%、101.5%±1.3%及99.3%±1.5%;血中三种杀鼠剂检出限分别为0.4、0.6及0.4mg/L。  相似文献   

6.
报道了以S- 十二烷基双硫腙- 苦味酸为载体制备苦味酸根离子电极, 研究了电极的性能, 并以该电极为指示电极研究了硝酸胍的单点滴定分析, 导出了定量关系式。 以0 .100 0 mol/ L 标准硝酸胍溶液滴定0 .100 0 mol/L 苦味酸, 控制滴定至95 % ,10 次实验的平均值为0 .100 2 mol/L, 相对标准偏差为0 .24 % , 滴定至90% ~95 % 相对标准偏差小于0 .3 % 。 用该法进行工业硝酸胍含量分析, 数分钟就能完成, 结果与重量法很好吻合。  相似文献   

7.
2.5次微分溶出伏安法同时测定人脑中铜,铅,镉,锌   总被引:3,自引:0,他引:3  
本文通过硝酸-硫酸混合酸消化脑样,在0.03mol/LHClO4底液中,采用悬汞电极2.5次微分阳极溶出伏安法同时测定人脑中铜、铅、镉、锌四种微量元素。在选定的实验条件下,所述元素的浓度在5~100ng/mL范围内与峰高成线性关系。用于人脑中铜、铅、镉和锌的分析,其相对标准偏差分别为6.5%、10.5%、12.7%和3.1%,其回收率为98.0%、94.0%、102.0%和104.0%。  相似文献   

8.
乳液电导法对麻黄中麻黄碱和伪麻黄碱的分步检测   总被引:3,自引:0,他引:3  
鲁传华  姚先梅  施蕾  李兵  葛慧 《分析化学》2000,28(8):1002-1005
使用水-界面膜-油体系通过物质具有不同的酸离解常数及透膜常数以提高电导滴定方法的选择性,对麻黄草中的混合生物碱进行了分步测定,终点明确。盐酸麻黄碱回收率99.8%±0.8%。麻黄草中麻黄碱含量0.41%、伪麻黄碱0.10%,其余生物碱0.06%,生物碱总量0.58%,与HPLC法结果总体一致。  相似文献   

9.
食品中甜蜜素的紫外分光光度法测定   总被引:16,自引:2,他引:14  
采用紫外分光光度法测定食品中的甜蜜素。该法在0.2~1.0g/L甜蜜素范围内符合比尔定律,回收率为95.0%~102.7%,相对标准偏差(RSD)为2.66%~5.40%,食品中共存的苯甲酸、山梨酸、糖精钠在0~10.0g/L范围内,色 0~2.0g/L范围内不影响测定。方法简捷,准确。  相似文献   

10.
病人血样中痕量锗,锶的石墨炉原子吸收光谱法测定   总被引:2,自引:1,他引:2  
本文运用石墨炉AAS法加基体改进技术,测定了50岁以上病人血清及环境水样中锗和锶的含量。用0.01mol/LHNO3-0.1%TritonX-100稀释血清,测定精度可与火焰法媲美。锗,锶的特征量分别为28pg和18pg;线性范围为0-250ng/mL和-35.0ng/mL;相对标准偏差(n=10)4.10%和2.49%;回收率分别为92.2%-99.0%和92.0%102%。方法快速准确,结果满  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.
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   

15.
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   

16.
针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。  相似文献   

17.
18.
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   

19.
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   

20.
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   

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