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1.
王焕龙  易兵 《化学分析计量》2002,11(1):36-37,39
研究了水杨醛二缩乙二胺锰(Ⅱ)配合物为载体的阴离子选择性电极。结果表明,水杨醛二缩乙二胺锰(Ⅱ)配合物对SO_3~(2-)有较高的选择性,且电极呈现反Hofmeister行为,其选择性次序为SO_3~(2-)>I~->SCN~->ClO_4~->NO_2~->NO_3~->S_2O_3~(2-)>Cl~->SO_4~(2-)。该电极响应速度快,具有良好的稳定性。用于化学试剂中SO_3~(2-)的测定,相对标准偏差为0.42%。  相似文献   

2.
高芷芳  盛怀禹 《有机化学》1986,6(3):210-212
以长链季铵盐为活性物研制成功PVC膜三氯乙酸根离子选择电极。该电极在1×10~(-1)~2×10~(-6)M Cl_3CCOO-离子浓度范围内显示良好的Nernst响应,检测下限为1.2×10~(-6)M。用固定干扰法测定了该电极对Ac~-、Cl~-,SO_4~-、H_2PO_4~-、HCO_3~-、CO_3~-,Cl_2CHCOO~-、NO_3~-等离子的选择性系数,仅NO_3~-有明显干扰。电极适用于中性、偏碱性溶液,在1×10~(-3)M Cl_3CCOONa溶液中,pH 7.0~12.5电势读数稳定。电极连续工作五小时电势变化为±1mV,可以作为一种分析三氯乙酸盐的简便快速方法。这对控制环境污染,判断职业中毒都十分重要。  相似文献   

3.
本文用正交试验法对影响InBr_4~-离子选择性电极的两项主要性能指标的主要因素进行了挑选,确定了一种线性较好、斜率较高的最优因子组合。电极的能斯特响应范围为1×10~(-1)—5×10~(-5)M,斜率56.1±1.1mV/pC,1×10~(-1)—1×10~(-4)M三次级差的平均偏差为2.0±1.0mV/pC。电极的稳定性与选择性较好。  相似文献   

4.
本文提出碳毡电极特征密度新概念,即碳毡电极对溶液中镉离子富集时,当碳毡在电极管中的密度为0.040—0.120g/cm~3时,富集效率随密度增加而增大。当密度大于0.120g/[cm]~3时,富集效率几乎不变。并由浓度为1×10~(-8)—1×10~(-5)g/ml的古镉离子溶液富集实验数据得到证明。  相似文献   

5.
首次研究以苯甲醛缩氨基脲铜(II)[Cu(II)-BASA]为中性载体的PVC膜电极, 该电极对硫氰酸根离子(SCN~-)具有优良的电位响应特性并呈现出反Hofmeister 选择性行为,其选择性次序为:SCN~- > ClO_4~- > I~- > Sal~- > Br~- > NO_3~- > Cl~- > NO_2~- > SO_3~(2-) > SO_4~(2-) > H_2PO_4~-。电极在pH 6. 0的磷酸盐缓冲体系中,对SCN~-在1.0 * 10~(-1)~8.0 * 10~(-6) mol/L浓度范围 内呈近能斯特响应,斜率为56.0 mV/sSCN~- (28 ℃),检测下限为3.0 * 10~(-6) mol/L。采用交流阻抗技术和紫外可见光谱技术初步研究了阴离子与载体的作用机 理,结果表明配合物中心金属原子的结构以及载体本身的结构与电极的响应行为之 间有非常密切的构效关系。该电极具有响应快、重现性好、检测限低、制备简单等 优点。将电极初步应用于实际样品废水分析,结果与HPLC法一致。  相似文献   

6.
首次研究以苯甲醛缩氨基脲铜(II)[Cu(II)-BASA]为中性载体的PVC膜电极, 该电极对硫氰酸根离子(SCN~-)具有优良的电位响应特性并呈现出反Hofmeister 选择性行为,其选择性次序为:SCN~- > ClO_4~- > I~- > Sal~- > Br~- > NO_3~- > Cl~- > NO_2~- > SO_3~(2-) > SO_4~(2-) > H_2PO_4~-。电极在pH 6. 0的磷酸盐缓冲体系中,对SCN~-在1.0 * 10~(-1)~8.0 * 10~(-6) mol/L浓度范围 内呈近能斯特响应,斜率为56.0 mV/sSCN~- (28 ℃),检测下限为3.0 * 10~(-6) mol/L。采用交流阻抗技术和紫外可见光谱技术初步研究了阴离子与载体的作用机 理,结果表明配合物中心金属原子的结构以及载体本身的结构与电极的响应行为之 间有非常密切的构效关系。该电极具有响应快、重现性好、检测限低、制备简单等 优点。将电极初步应用于实际样品废水分析,结果与HPLC法一致。  相似文献   

7.
研制成功了两种类型的阴离子涂丝电极;设计了以涂丝电极为指示电极,甘汞电极为参比电极的流通池;选择了适合PVC膜阴离子电极的低容量色谱柱及SO_4~(2-)—H_2PO_4~-缓冲体系作为淋洗剂;解决了鉴定器、色谱柱、淋洗剂三者相匹配这一难题,得到了Cl~-、Br~-、NO_2~-、NO_3~-、四组份分辨良好的色谱峰。利用选定的上述色谱系统对该鉴定器的主要性能进行了鉴定。在此基础上建立了以涂丝电极为鉴定器的液相色谱法,对各种环境样品中的Cl~-、Br~-、NO_2~-、NO_3~-进行同时测定。方法简单快速,灵敏度高,精密度好,适用于各种环境水样中上述组分的同时测定。  相似文献   

8.
报道了以PVG-双硫腙(DTZ)-Cu(Ⅱ),PVC-DTZ-Cu(Ⅰ)为载体制备了性能良好的SCN-离子电极,其选择性次序为SCN~-》ClO_4~->Sal~-》NO_3~-~Cl~->PO_4~(2-)。16℃时,膜组成为PVC-DTZ-Cu(Ⅰ):PVC:邻硝基苯基辛醚(o-NPOE)=12∶22∶66的SCN~-离子电极,在0.02mol/LHCl体系中,在1×10~(-2)~5×10~(-6)mol/LSCN~-浓度范围呈能斯特响应,斜率为58±2mV/dec,检测限为2×10~(-6)mol/L;膜组成为PVC-DTZ-Cu(Ⅱ)∶PVC∶o-NPOE∶四苯硼酸钾(KTPB)为8∶22∶55∶15的电极,在0.01mol/LHAc-NaAc缓冲体系中,在10~(-2)~2×10~(-6)mol/LSCN~-浓度范围呈线性响应,斜率为54∶1mV/dec,检测限为8×10~(-7)mol/L.研究了阴离子与载体作用的机理,表明SCN~-与载体中铜原子直接作用。电极应用于废水中SCN~-的测定,结果令人满意。  相似文献   

9.
本文描述的多孔银膜电极,有如下特点:(1)可以用作银电极,响应2×10~(-5)~10~(-2)MAg~+,响应斜率为123mV/级差。(2)可以转化为几种银基/难溶盐类型的离子选择性电极,如:Ag/AgSCN、Ag/AgBr、Ag/AgCN、Ag/AgI和Ag/Ag_2S,用于测定电极盐阴离子。浓度改变10倍,各阴离子的响应斜率是:  相似文献   

10.
本文发现Cu~(2+)离子对二溴代苤硒脑在悬汞电极上的吸附溶出行为有显著增敏作用,从而建立了灵敏度高、选择性好的测定痕量硒的吸附溶出伏安法。线性范围为0.02~50ng/ml,检出下限达5×10~(-4)ng/ml。本文初步探讨了Cu~(2+)的增敏机制。  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.
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   

16.
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   

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.
19.
The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.  相似文献   

20.
设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。  相似文献   

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