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1.
氢化物发生原子荧光法测定灵芝中的痕量锗   总被引:12,自引:0,他引:12  
建立了HG-AFS测定灵芝样品中总锗的方法,将微波密封消解应用于样品的处理,短时内成功地破坏了有机锗,同时避免了样品中存在的氯离子可能引起的元素损失。实验中优化了仪器的工作条件、锗氢化物发生最佳条件及微波消解程序。样品最优酸度为20%H3PO4,且5%H2SO4能增强锗的荧光强度。将干灰化法与微波密封酸消解法对植物样品的处理做了比较。本方法的检出限为0.83μg/L;相对标准偏差为1.26%;加入回收率为84.0%-96.5%。本法可以较好的满足实际植物样品中锗的分析。  相似文献   

2.
微波消解-分光光度法测定石油焦中的钒   总被引:1,自引:0,他引:1  
研究了用微波消解分光光度法测定石油焦中的钒。在石油焦样品处理中采用了常规溶样及微波消解两种方法。重点研究了微波消解石油焦样品的方法,详细考察了微波消解时样品的最佳用量、消解压力、功率、时间,建立了最佳微波消解程序。结果表明两种方法测定结果基本吻合。样品测定的RSD小于4、02%,加标回收率均在98.6%~102.7%之间,但微波消解法的溶样速度是常规法的10倍。钒的线性范围为0~8.0g/L。结果表明,微波消解分光光度法测定石油焦中的钒是一种快速、准确且无环境污染的方法。  相似文献   

3.
微波消解-分光光度法测定催化裂化原料中铁和镍   总被引:1,自引:0,他引:1  
采用微波消解技术处理催化裂化原料,用分光光度法测定样品中的铁和镍。详细考察了微波消解消化剂的种类和用量,消解时间,消解压力和消解功率对消解效果的影响,确定了最佳微波消解程序。将微波消解技术与常规分光光度法结合测定催化裂化原料中的铁和镍,与常压溶样方法测定结果相吻合。该方法的相对误差小于0.9%,相对标准偏差(n=5)小于2.7%,两种样品制备方法的加标回收率均在95.2%~102.4%之间。实验结果表明:该方法简便、快速、准确、节省试剂、无环境污染,在催化裂化原料质量检测方面切实可行。  相似文献   

4.
采用微波消解方法处理汽油样品,用微波等离子体炬原子发射光谱法(MPT—AES)测定消解液中的铜和铁含量。考察了微波功率、载气流量、工作气流量、酸效应、共存离子等实验参数对测定铜和铁的影响,并进行了系统优化,测得铜和铁的检出限分别为2.1ng/mL和22.1ng/ml。线性范围分别为0.01~12μg/mL和0.1~100μg/mL。详细考察了微波消解酸种类及用量,消解温度、运行时间及微波功率等对微波消解的影响。结果表明,各元素测定结果的RSD均小于3.5%,铜的回收率为93%-107%,铁的回收率为92%-106%。与传统的碘-二甲苯-硝酸反萃取处理法相比,此法具有元素损失少,操作简单,无需使用有毒氧化剂,减少污染,改善工作环境等优点,是行之有效的汽油样品预处理方法。  相似文献   

5.
等离子体发射光谱法测定城市污泥中重金属   总被引:1,自引:0,他引:1  
采用微波消解技术消解处理样品,建立了等离子体发射光谱法同时检测城市污泥中微量金属元素Cu、Zn、Ni、Cd、Cr、K、B及Pb的方法。讨论了微波消解液、消解参数对消解效果的影响,在最佳实验条件下,微波消解法各元素测定结果的相对标准偏差为1.06%-3.20%(n=6),加标回收率为93.1%-104.0%。结果表明该方法精密度高,准确性好,快速简单,适于城市污泥中的重金属的测定。  相似文献   

6.
采用微波消解技术消解原油和渣油,利用微波等离子体炬原子发射光谱法测定原油和渣油中的Fe、Ni、Cu、Na。考察了原油和渣油的最佳消解条件、各元素测定条件及共存元素对测定的影响。方法对Fe、Ni、Cu和Na元素的检出限分别为22、42、2.0和1.0μg/L;线性范围分别为0.1-100、0.15-50、0.01-5.0和0.006-2.0mg/L,应用该方法测定实际样品中Fe、Ni、Cu和Na的相对标准偏差分别为3.9%、3.6%、5.5%和3.4%。微波消解样品的测定结果与常规干法灰化法的测定结果相吻合。本方法省时、省酸、简便、快速,没有环境污染,具有一定的实际应用价值。  相似文献   

7.
水中总磷量的密闭微波增压消解快速测定   总被引:4,自引:0,他引:4  
研究了用聚四氟乙烯密封带密封容器,利用微波加热技术,在较高的温度和压力下消解样品,快速测定环境水样中总磷量的方法;讨论了微波功率、微波消解时间、酸度等因素对测定结果的影响,与标准方法对照,经t检验法及F检验法检验,测定结果没有显著性差异,多次加标回收率在98%-103%之间,相对标准偏差≤1.3%,结果令人满意;该法具有操作简便、快速、不污染环境、宜于大批量样品的测定、便于推广普及等优点,可用于其它样品的分析测定。  相似文献   

8.
加热处理-气相色谱法测定韭菜中有机磷农药残留量   总被引:13,自引:0,他引:13  
建立了GC-FPD测定韭菜中7种有机磷农药残留量的方法。未经过处理的韭菜本底色谱图杂峰对韭菜中有机磷农药残留量的测定有影响;采用加热处理样品3min的方法,可有效去除干扰物,使韭菜本底色谱图杂峰变小。经过加热处理后的韭菜本底杂峰对测定韭菜中7种有机磷农药残留量基本没有影响。方法回收率87.12%~110.9%,RSD 1.4%~8.7%,检出限0.005~0.010mg/kg。  相似文献   

9.
氢化物发生-原子荧光法测定茶叶中的痕量锗   总被引:1,自引:0,他引:1  
用微波消解、氢化物发生-原子荧光光谱法测定了3种富硒茶中微量锗的含量,考察了仪器工作条件、样品酸度、载流酸度、硼氢化钾和增敏掩蔽剂酒石酸的用量等因素对荧光强度的影响。结果表明,在最佳工作条件下,0~80μg·L^-1内线性关系良好,相关系数0.9999,检出限0.0389μg·L^-1,标准相对偏差0.80%,加标回收率90.4%~104.5%。  相似文献   

10.
研究建立了ICP—AES同时测定TiNi形状记忆合金中Co、Cu、Cr、Fe、Nb5元素的方法。进行了必要的条件试验,选择了分析线及其他仪器工作参数;考察了方法检出限、H2SO4酸度及基体钛、镍对测定的影响、工作曲线线性。进行了准确度和精密度试验,各元素的加标回收率为Co98.4%。99.6%、Cu98.0%~103%、Cr98.9%~99.6%、Fe94.6%~95.8%、Nb99.8%。102%。5种元素的相对标准偏差范围为4.2%-10%。  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.

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   

14.
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   

15.
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   

16.
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   

17.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

18.
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   

19.
袁丽秋 《化学教育》2006,27(5):8-10
面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。  相似文献   

20.
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