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1.
铕对决明发根生长及有效成分生成的作用   总被引:2,自引:0,他引:2  
以决明发根为材料,在培养基中附加0.001~10mg.L^-1Eu^3+(EuC13),测量发根的鲜重和干重,用高效液相色谱法测定游离蒽醌化合物含量。发有低剂量(0.001,0.01,1.0mg.L^-1)Eu^3+抑制生长,0.001mg.L^-1Eu^3+抑制作用最强,干重比对照降低22%;较低剂量(10mg.L^-1)Eu^3+处理的含量高于对照26^,高于Eu^3+1.0mg.L^-1处理  相似文献   

2.
锆硼陶瓷材料中总硼分析方法研究   总被引:1,自引:0,他引:1  
卢菊生  田久英 《分析化学》2005,33(8):1161-1163
对锆硼陶瓷材料中总硼的分析方法进行了研究,采用硫酸和硫酸铵及重铬酸钾氧化两步溶解法分解样品,氮气载带硼酸三甲酯蒸馏分离硼与锆(氦气流速150mL/min水溶加热,NaOH溶液吸收),材料中成分为Zr粉+B4C粉,Zr含量≥99%(ut),经阳离子交换法除去吸收液中Na后采用ICP-AES法测定硼。方法的相对标准偏差(n=6)小于2.0%;标准加入回收率为99%。  相似文献   

3.
以莲藕为材料,研究了施用磷肥和有机肥及两者混施对莲藕根状茎品质和表面铁膜形成的影响,以期为高产优质莲藕的种植提供理论依据。结果表明,磷肥处理后莲藕根状茎中蛋白质和淀粉含量分别比对照增加了145.4%和61.5%,并且还原糖含量和维生素C含量也比对照提高了48.2%和112.7%,根状茎表面铁膜的铁含量显著低于对照。有机肥处理下蛋白质和还原糖含量分别比对照提高了54.0%和47.2%,但莲藕根状茎中的淀粉、维生素含量以及铁膜的产生与对照无显著差异。磷肥+有机肥处理的效果仅次于磷肥。可见磷肥施用后有效提高了莲藕品质并减轻了根状茎表面铁膜沉积,这对于提高种藕效益具有非常重要意义。  相似文献   

4.
本文报告了在0.01mol/LCTAB体系中,以F-为掩蔽剂、苯芴酮显色、用分光光度法测定饮料食品中Ge-132含量,最低检测限0.054μg/mL;线性范围0.54~27.14μg/mL;回收率96.3%~101.5%,并确定了Ge-132摩尔吸收系数(ε)3.39×104。用本法测定了康寿茶、矿泉水和博士奶中Ge-132含量,灵敏度高、重现性和准确度好。用盐酸化本体系,研究了二氧化锗(Ge~(4+))的含量测定,其最低检测限0.021μg/mL;线性范围1.0~21.0μg/ml;回收率95.8%~102.8%,Ge-132不干扰。饮料食品中同时存在Ge-132和Ge(4+)时,本体系可分别测定两者含量。  相似文献   

5.
不经分离,高敏,连续光度滴定混合物中钕和铁   总被引:3,自引:0,他引:3  
提出以Fe(3+)(Nd(3+)-CAS-CPB-C2H5OH作为不经分离、高敏、连续光度配合滴定混合物中Fe(3+)和Nd(3+)的多元胶束配合指示体系。滴定Fe(3+)和Nd(3+)的适宜pH分别为2.3~3.2和6.0~8.6。用EDTA目视滴定Fe(3+)时,终点处由蓝紫变粉红色,对比度大(Δλ=130nm)、灵敏度高(配合物摩尔吸光系数ε(630)=1.14×105L·cm(-1)·mol(-1),至少可检测0.4μg/mL,滴定线性范围为0~2.8μg/mL。线性相关系数为0.9994;目视滴定Nd(3+)时,终点处由绿色变橙黄,Δλ>180nm,ε(630)=7.6×104,至少可检测1μg/mL,滴定线性范围0~3.7μg/mL,线性相关系数0.9994。对于铁钕硼混合物样品则不经分离在630nm处连续光度滴定,可更精密、高敏、准确地确定终点,变异系数1.76%~2.86%,标准加入回收率96%~104%,且简便、快速。  相似文献   

6.
为探讨氟化钠对幼年大鼠血清4种微量元素和骨矿物质含量的影响,以及大鼠骨矿物质和血清微量元素的相关性,将80只2月龄SPF级SO大鼠,雌雄各半,随机分成8组:对照(幼年CS、成年AS)组和用药组(幼年高氟组CHS、幼年低氟组CLS、成年高氟组AHS、成年低氟组ALS、幼年长期高氟组HS、幼年长期低氟组15)。对照组灌胃生理盐水,用药组分别按相应时间给予不同剂量的NaF灌胃,测定了大鼠尺骨和血清中的Ca、P、Fe、Zn含量。结果表明,(1)血清微量元素:①与cs组相比,CHS组和CLS组的磷(P)分别增加100.0%和193.8%(P〈0.05)。②与AS组相比,HS组的Ca、Zn分别下降了20.5%和40.0%,而P则增加了74.0%(P〈0.05);Ls组的Zn下降了33.3%(P〈0.05)。与HS组比较,CHS组的Ca增加22.3%。③与LS组比较,CLS组的P和Zn明显增加49.2%和28.5%(P〈0.05)。(2)骨矿物质:①与As组相比,HS组的Ca分别下降了23.9%(P〈0.05),Zn则增加了36.1%(P〈0.05)。②与HS组相比,CHS组的Ca和Fe分别增加了42.3%和36.05%,Zn下降了38.6%(P〈0.05)。(3)骨矿物质和血清微量元素的相关性:骨Ca和血Ca、骨P和血P、骨Zn和血Zn、骨Fe和血Fe的相关系数分别为0.435、0.347、0.136和0.059(P〉0.05)。提示长期使用氟化钠,可以导致幼年大鼠血中微量元素代谢紊乱,骨矿物含量降低,但未确定大鼠骨矿物含量和血微量元素具有相关性。  相似文献   

7.
采用V(浓硝酸)+V(高氯酸)=4+1混酸溶解消化样品。用火焰原子吸收光谱法(FAAS)测定了红芪、黄芪、板蓝根中K、ca、Na、Mg、Fe、Mn、Zn、Cu8种微量元素的含量。结果表明,红芪中钙的含量最高,铜的含量最低;黄芪和板蓝根中镁的含量最高,铜的含量最低。各元素回收率(n=7)在96.07%~101.26%之间,RSD值(n=7)在0.60%~2.99%之间。  相似文献   

8.
反相高效液相色谱法测定辣椒果实中辣椒素含量   总被引:2,自引:0,他引:2  
欧阳华学  王凌志 《分析化学》1998,26(12):1529-1529
1引言辣椒是我国广泛栽培的蔬菜作物,品种多,资源丰富,为了对大批辣椒品种资源进行辣味品质鉴定,需建立快速测定辣椒果实中辣椒素(capsaicin)含量的方法。在国内,辣椒素的测定一般采用分光光度法,但该方法的样品前处理繁琐,且灵敏度较低。应用反相高效液相色谱法进行辣椒素的定量分析在国内尚未见报道,本文对辣椒果实中辣椒素的卒取及色谱分离条件进行了探讨,得到了满意的分离效果。2实验部分2.1仪器与试剂Vallan5000型高效液相色谱仪,UV-100可变波长紫外检测器,CDS401数据处理系统。辣椒…  相似文献   

9.
含铜三元类水滑石化合物的合成及其性质   总被引:11,自引:0,他引:11  
 以Cu(NO3)2,Zn(NO3)2和Al(NO3)3为原料,以NaOH为沉淀剂,利用共沉淀法合成了含铜三元类水滑石化合物CuZnAl-HTLcs.从不同Cu/Zn/Al比的混合原料溶液的滴定曲线入手,详细探讨了溶液pH值、原料加入方式、组分配比及水热处理条件对类水滑石合成的影响,利用XRD,ICP及比表面积测定对合成物进行了表征,并以苯酚羟基化为探针反应评价了催化剂的催化性能.结果表明,在体系pH=5.0~6.2,(Cu+Zn)/Al摩尔比=2.0,Cu/Zn摩尔比≤1.0及室温条件下共沉淀后,于100℃水热处理3h,即可得到晶相单一和结晶度高的CuZnAl-HTLcs.变化pH法合成的样品的相对结晶度为100%,低过饱和法为76.5%,高过饱和法为75.9%.合成的CuZnAl-HTLcs中Cu2+的含量均比原料液中Cu2+的含量有所增加,这可能是由于在pH=5.8时Cu2+对Al(OH)3的同晶取代能力比Zn2+强.随着CuZnAl-HTLcs中Cu含量的增加,催化剂对苯酚羟化反应的催化活性逐渐增大.  相似文献   

10.
倒数示波计时电位法同时测定粮食中Cu、Pb含量   总被引:1,自引:0,他引:1  
在分别含有2g/L乙二胺与*10^-4mol/L8-羟基喹啉(Oxine)和0.3mol/L的氢氧化钠淀粉液中,Cu^2+、Pb^2+具有良好的示波图。其切口电位分别为-0.85V,-120V(vs.SCE),二者相差0.35V,能够分辨,可同时测定,本方法应用于大米中Cu、Pb含量的同时测定,检出限分别为5.8μg/L(Cu)、10.0μg/L(Pb),平均回收率为96.0%、102.0%。  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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