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1.
It has been found that the Sm-BPMPHD-CTMAB ion association system shows a strong fluorescence intensity. In this system some rare earth ions, such as Lu3+, Y3+, Gd3+ and Tb3+, exert an evident fluorescence enhancement effect. The formation conditions of the system and the factors affecting the columinescence effect were studied in detail in order to determine trace amounts of Sm3+. Under optimum conditions a linear relationship was obtained between the fluorescence intensity and the Sm3+ concentration in the range of 5.0×10?8–8.0×10?6 mol·L?1. The detection limit of Sm3+ was 2.0×10?8 mol·L?1. The determination gave satisfactory results.  相似文献   

2.
SynthesisandCrystalStructureof1,5-Bis(1'-phenyl-3'-methyl-5'-pyrazolone-4')-1-(4'-aminobutand-1'-imino)-5-pentaneone¥YangLu-Q...  相似文献   

3.
A fluorescent enhancement system carminic acid (CA)-La3+-CTAB is found and based on this finding a new fluorimetric method for the determination of CA is developed. Under optimized conditions, the enhanced intensities of fluorescence are quantitatively in proportion to the concentrations of CA in the range of 0.01231-12.31 μg mL(-1). The detection limit is 10.92 ng mL(-1). Compared with other methods that have been reported to determine CA, this method has high sensitivity, stability and wide linear range. In addition, the luminescence mechanism indicates that the complex of La3+-CA (1:2) forms and solubilizes in CTAB micelle.  相似文献   

4.
研究了1,9-双(1′-苯基-3′-甲基-5′-氧代吡唑-4′-基)壬二酮-(1,9)(BPMPND,H2A)与三辛基氧膦(TOPO,B)的氯仿溶液,从硝酸介质中对La(Ⅲ),Dy(Ⅲ)的协同萃取,计算了体系的酸性协萃系数RA和协萃系数R,用斜率法测得协萃合物的组成LaA.HA.B和DyA.HA.B计算了协萃取平衡常数,研究了温度对协萃反应的影响,用萃取法制得了固态协萃合物,并对其组成,IR及TG  相似文献   

5.
6.
The phase behavior of aqueous mixtures of gemini surfactant hexylene-1,6-bis(dodecyldimethylammonium bromide) (12-6-12) and oppositely charged polyelectrolyte sodium polyacrylate (NaPAA) has been studied experimentally. Compared to the mixtures of the traditional surfactant dodecyltrimethylammonium bromide (DTAB) and NaPAA, the gel phase region in the 12-6-12/NaPAA solution is larger. Element analysis reveals that NaPAA in the gel phase tends to replace the counterions of surfactant micelle and to release its own counterions. Spherical aggregates are observed in either top or bottom gel phase as detected by transmission electron microscopy. The addition of sodium bromide (NaBr) leads to a decrease in the gel phase region and the occurrence of a new cream phase.  相似文献   

7.
The supramolecular systems of 5-(p-hydroxyphenyl)-10,15,20-tris-(4-chlorophenyl)porphyrin (p-HTClPP) with beta-cyclodextrin (beta-CD), heptakis(2,3,6-tri-O-methyl)-beta-CD (TM-beta-CD), carboxymethyl-beta-cyclodextrin (CM-beta-CD) and sulfurbutylether-beta-CD (SBE-beta-CD) have been investigated by means of absorption, fluorescence and (1)H NMR spectroscopy. The formation of inclusion complexes has been confirmed on the base of changes of spectroscopy properties. "The double reciprocal method" has been used to determine the stoichiometry and the inclusion constants of p-HTClPP with the four cyclodextrins (CDs). The results show that p-HTClPP can form 1:1 inclusion complexes with the four CDs. Compared with parent native beta-CD, the inclusion abilities of modified beta-CDs with p-HTClPP are stronger. It indicates that the hydrophobic effect plays an important role in the inclusion procedure. The mechanism of inclusion interaction was examined by (1)H NMR technique. During the study of p-HTClPP-TM-beta-CD supramolecular complex, an efficient enhancement of fluorescence intensity was observed. Based on this phenomenon, fluorometric method for the determination of p-HTClPP was developed. The relationship between fluorescence intensity and the concentration of p-HTClPP is linear from 1.0 x 10(-9) to 7.0 x 10(-6)mol L(-1). The limit of detection is 8.3 x 10(-10)mol L(-1) and the relative standard deviation (R.S.D.) is 1.3% (n=8). This research will provide useful information for further application of p-HTClPP.  相似文献   

8.
The oxime of the hitherto unknown 3-amino-5-nitrobenzaldehyde was synthesized by the reaction of 3-amino-5-nitrobenzaldehyde phenylhydrazone with excess of (NH2OH)2·H2SO4. The oxime obtained was used as the starting compound for the synthesis of novel diaryl- and arylnitrofuroxans. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2232–2235, December, 1997.  相似文献   

9.
10.
Yumei Guo  Xia Wu  Hongzhi Mao 《Talanta》2007,73(2):227-231
A new fluorimetric method for the determination of epinephrine is established by rare earth co-luminescence effect of Tb-Gd-E-Tris system. Under optimum conditions, a linear relationship has been obtained between the fluorescence intensity and the concentration of epinephrine in the range of 1.8 × 10−8 to 2.5 × 10−6 mol/l, and the detection limit is 4.5 × 10−9 mol/l (S/N = 3). The method is applied for the determination of epinephrine in injection and the recovery test in urine by standard addition method, and the results obtained are satisfactory. The mechanism of the co-luminescence in the system was also discussed.  相似文献   

11.
12.
Yang T  Qin W  Liu W 《Talanta》2004,62(3):451-456
A new bis-Schiff base ligand, bis-(trimethylolaminomethane)-4-tert-butyl-disalicylicimine (HL), was synthesized. The fluorescence intensity of HL-Zn2+ complex was increased by about 8-fold upon addition of β-cyclodextrin (β-CD). The spectrofluorimetric determination of trace amounts of Zn2+ based on the phenomenon was carried out. The excitation and emission wavelengths are 405 and 465 nm, respectively. Under optimal conditions, the fluorescence intensities vary linearly with the concentration of Zn2+ in the range 0-317 μg l−1 with a detection limit of 1.0 μg l−1. The interferences of some inorganic ions were described. The method is a selective, sensitive, rapid, and simple analytical procedure for the determination of Zn2+ in crops. The mechanism for the fluorescence enhancement was also discussed.  相似文献   

13.
A new salicylic-based open-chain crown ether ligand, 1,10-bis(2′-carboxylphenyl)-1,4,7,10-tetraoxadecane (BCPTD) was synthesized. Solutions of its complex with Tb3+ can emit the intrinsic fluorescence of Tb3+. The fluorescence intensity of the complex in KCl solution was enhanced by the addition of silver(I), leading to a new fluorescence enhancement phenomenon. The spectrofluorimetric determination of traces of silver(I) based on the above phenomenon was carried out. The excitation and emission wavelengths are 298 and 545 nm, respectively. Under optimal conditions, the differential value of fluorescence intensity in the absence and presence of Ag+ was proportional to the concentration of silver(I) in the range 0.5-20 μg ml−1. The method was applied to the determination of silver(I) in a standard ore sample. The analytical performance is investigated in detail by using common aromatic carboxylic acids or synthetic analogues of BCPTD as ligands to replace BCPTD. It was found that Tb-aromatic acid complexes did not result in fluorescence enhancement of Tb3+ in AgCl collosol. The phenomenon was only observed in Tb(III) with BCPTD or its open-chain crown ether analogues solutions.In addition, the enhancement of the fluorescence intensity of terbium(III) in these complexes depends on the extent of formation of the AgCl collosol.  相似文献   

14.
N-Cyano-N-allylamino-sym-triazines, which were synthesized by the reaction of allyl bromide and the potassium salts of cyanoamino-sym-triazines, were converted to 2-(4'-methyl-1',3'-imidazolidon-1'-yl)-sym-triazines by the action of hydrogen peroxide in an alkaline medium. A similar transformation occurred in hydrochloric acid or under the influence of hydrogen chloride in alcohol. The structures of the products were confirmed by IR and mass-spectral data and alternative synthesis.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 847–850, June, 1984.  相似文献   

15.
近年来,由于电子学的进展,出现了带有微处理机的多功能的分光光度计及双波长双光束分光光度计,从而使导数吸收光谱法有了迅速发展.但用于稀土元素的研究却不多,只有Shibata等与任英等的报道.我们曾指出,β-二酮与有机碱和Ln~(3+)形成三元配合物时会提高镧(III)系离子超灵敏跃迁吸收带的强度;由于f-f跃迁峰毕竟较弱,所以灵敏度很低.而陡峻的f-f跃迁峰及其劈裂恰好给导数吸收光谱提供应用的条件.本文是镧(III)系三元配合物分析化学研究的继续,用导数吸收光谱法对Ln~(3+)—1-苯基-3-甲基-4-苯甲酰基吡唑酮-[5](Hpmbp)-二苯胍(DPG)体系进行了研究.  相似文献   

16.
The total syntheses of the first examples of diarylheptanoid natural products (5S)-5-acetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)-3-heptanone 1, and (3S,5S)-3,5-diacetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)heptane 2 isolated from the rhizomes of Zingiber officinale were accomplished using Sharpless epoxidation and cross-metathesis reactions as the key steps.  相似文献   

17.
合成了[1,6-双(1'-苯基-3'-甲基-5'-吡唑啉酮-4']-己二酮[1,6]合稀土(La,Dy)酸(E)-N-十六烷基-4-(2,4'-二甲氨基苯基)乙烯基吡啶两个新的稀土配合物。用元素分析、紫外可见光谱、红外光谱、差热热重谱、X射线粉末衍射、核磁共振谱和摩尔电导测量对配合物进行了表征。空气-水(18℃,pH5.4)界面上的表面压-面积(π-A)等温线研究表明,两配合物的Langmuir成膜性明显优于半菁溴化物和碘化物。二次谐波发生(SHG)实验测得镝配合物的二阶分子超极化率β为4.8×10^-^4^8C m^3 V^-^2,较半菁碘化物大约3.4倍。  相似文献   

18.
The fluorescence system of the Eu3+ (or/and Sm3+)-2-benzoyl-indane-1,3-dione(BID)-cetyltrimethylammonium bromide (CTMAB) was investigated at excitation wavelengths of 350 nm, and emission wavelengths at 612 nm for europium and 565, 606 and 650 nm for samarium, respectively. The system was used for the determination of Eu and Sm in rare earth oxides and of BID in water. Europium or/and samarium could be determined in the range of 1.0 × 10–9–1.0 × 10–5 mol/L and 2.0 × 10–8–5.0 × 10–5 mol/L, respectively; 1.0 × 10–6–2.0 × 10–5 mol/L of BID could also be determined. Received: 5 March 1997 / Revised: 6 August 1997 / Accepted: 20 September 1997  相似文献   

19.
The mass spectral. behavior of 1,6-bis(arylsulfenyl)-2,4-hexadiynes and 1,6-bis(arylsulfonyl)-2,4-hexadiynes were examined. The sulfenyl derivatives extruded the hexadiynyl moiety with the formation of Ar? S? S? Ar fragments. The sulfonyl derivatives, on the other hand, showed no extrusion of the hexadiyne fragment but an expulsion of SO2 and even two SO2 units.  相似文献   

20.
钇-铕-美他环素-CTMAB稀土共发光体系的研究及分析应用   总被引:1,自引:0,他引:1  
利用荧光光谱法研究了钇-铕-美他环素(MTC)-CTMAB体系的稀土共发光效应,最佳形成条件,并对其作用机理进行了探讨,提出了测定MTC的荧光分光光度法。结果表明,共发光体系的荧光强度与MTC的浓度在1.0×10-7mol/L~1.5×10-5mol/L范围内呈良好的线性关系,其检出限为3.6×10-8mol/L。采用标准加入法测定了药物制剂中的MTC。  相似文献   

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