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1.
Shkumbatiuk R Bazel YR Andruch V Török M 《Analytical and bioanalytical chemistry》2005,382(6):1431-1437
A new, simple, rapid, and sensitive spectrophotometric method has been developed for the determination of nitrophenols [picric acid (PA); dinitrophenols (DNP)] in wastewater samples. The method is based on the reaction of nitrophenols with 2-[(E)-2-(4-diethylaminophenyl)-1-ethenyl]-1,3,3-trimethyl-3 H-indolium chloride reagent to form the colored ion associates, which are extracted by organic solvents. The molar absorptivity of the ion associates of PA with the investigated reagent ranges from 8.3×104 to 11.3×104 L mol–1 cm–1, depending on the extractant. Because only PA is extracted in an acidic medium with the investigated reagent, but both PA and DNP are extracted in an alkaline medium, it is possible to determine both substances in a mixture. Appropriate reaction conditions have been established. The absorbance of the colored extracts obeys Beers law in the range of 0.04–4.58 mg L–1 PA, 1.0–18.4 mg L–1 2,4-DNP and 1.2–14.7 mg L–1 2,6-DNP, respectively. The limit of detections, calculated from a blank test (n=10; P=0.95), are 0.05 mg L–1 PA, 0.9 mg L–1 (2,4-DNP), and 1.1 mg L–1 (2,6-DNP), respectively. 相似文献
2.
A. N. Tolmachev L. N. Babichenko I. V. Komarov S. V. Sereda A. K. Sheinkman 《Chemistry of Heterocyclic Compounds》1992,28(4):430-434
In the reaction of 1,3,3-trimethyl-2-cyanomethyleneindoline with ortho-phenylenediamine in polyphosphoric acid a Plancher rearrangement takes place with the formation of the previously unknown polycyclic system. The structure of the compounds obtained was established by means of x-ray diffraction analysis,1H and13C NMR spectra, and their ring-chain transformations were investigated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 513–518, April, 1992. 相似文献
3.
Vasil Andruch Monika Telepc˘áková Ioseph S. Balogh Nikoleta Urbanová 《Mikrochimica acta》2003,142(1-2):109-113
The complex formation and extraction of chromium(VI) with 2-[2-(4-methoxy-phenylamino)-vinyl]-1,3,3-trimethyl-3H-indolium
chloride reagent was studied by means of spectrophotometry. The influence of medium acidity, the concentration of chloride
ions and dye reagent, the nature of the extractant and some other factors (time of extraction, stability of color, interference,
etc.) on the absorbance of colored extracts were studied. The optimum conditions were found to be 0.02–0.1 M H2SO4, 1.0–1.5 M NaCl, (2.0–2.5) × 10−4 M of reagent. The absorbance of the colored extracts obeys Beer’s Law in the range of 0.26–7.28 mg L−1. The procedure of Cr(VI) extraction and spectrophotometric determination was examined.
Author for correspondence. E-mail: andruch@kosice.upjs.sk
Received November 19, 2002; accepted March 10, 2003
Published online June 13, 2003 相似文献
4.
Extractive separation, preconcentration, and determination of gold as an ion associate (IA) with 2-[2-(4-methoxyphenylamino)vinyl]-1,3,3-trimethyl-3H-indolium chloride in extracts by spectrophotometry and atomic
absorption spectrometry were studied. The optimal conditions were found for the extraction of IA with aromatic hydrocarbons
and acetate esters. The main chemical analytical properties of the ion associate were determined. The formation of IA enables
extractive separation of gold from Al, Cr, Mn, Fe, Co, Ni, Zn, Cu, Cd, Pt, Hg, Bi, Ag, Pb, and Pd. By varying the volume ratio
of the aqueous and organic phases in the range of (1–40): 1, one can combine extractive separation and the preconcentration
of gold and decrease the detection limit for gold to 0.031 mg/L (extraction-spectrophotometric determination) or 0.084 μg/L
(direct determination in extracts by electrothermal atomic absorption spectrometry). Procedures were developed for the determination
of trace amounts of gold, and their performance characteristics were calculated. 相似文献
5.
V. D. Sviridov N. D. Chkanikov M. V. Galakhov Yu. V. Shklyaev V. S. Shklyaev B. B. Aleksandrov M. S. Gavrilov 《Russian Chemical Bulletin》1990,39(6):1268-1272
1,3,3-Trimethyl-3,4-dihydroisoquinolines, which exist in the imine form, undergo C- hydroxyalkylation upon reaction with hexafluoroacetone and esters of trifluoropyruvic acid at the C1 CH3 group at 20°C. The products with the ketoesters are converted upon heating to -lactams. Derivatives of 1,3,3-trimethyl-3,4-dihydroisoquinoline substituted at C1 CH3 group and existing in the enamine form, react with esters of trifluoropyruvic acid at 20°C to give exclusively -lactams and do not give reaction products with hexafluoroacetone.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1405–1410, June, 1990. 相似文献
6.
The possibility of the spectrophotometric determination of piroxicam based on the extraction of its ion associate (IA) with the polymethine dye, 5-thiocyanate-1,3,3-trimethyl-2[(1E)-3-[(2E)-1,3,3-trime-thyl-1-H-indol-2-ilidine]-propenyl]-3H-indolium chloride. The maximal recovery of IA with toluene is achieved when pH of the aqueous phase is 8.0–12.0 and the concentration
of the dye is (1.0–2.0) × 10−4. The molar absorption coefficient of IA is 8 × 104, the detection limit of piroxicam is 0.49 μg/mL. A procedure has been developed for the extraction-spectrophotometric determination
of piroxicam in the concentration range 1.0–20.0 μg/mL. 相似文献
7.
Vladislav Yu. Korotaev Igor B. Kutyashev Yurii V. Shklyaev 《Tetrahedron letters》2008,49(37):5376-5379
The basic structural framework of lamellarin alkaloids, 8,9-dihydro-6H-chromeno[4′,3′:4,5]pyrrolo[2,1-a]isoquinoline derivatives, has been obtained in good yields via Grob reaction between 3-nitro-2-(trifluoromethyl)-2H-chromenes and 1,3,3-trimethyl-3,4-dihydroisoquinolines in refluxing isobutanol. When the reaction was carried out in toluene at room temperature, only Michael adducts, as a mixture of two diastereomers, were isolated. 相似文献
8.
Summary A new cationic dye, 1-(10-bromodecyl)-4-(4-aminonaphthylazo)-pyridinium bromide, was synthesized and evaluated as a new reagent for the determination of anionic surfactants. The reagent reacts with anionic surfactants, such as sodium dodecylsulphate and sodium dodecylbenzenesulphonate, to produce an ion associate in an aqueous medium. The colour change occurs simultaneously, and the colour development is very stable. This makes it possible to determine anionic surfactants directly by spectrophotometry without solvent extraction. The stoichiometric ratio of the ion associate was found to be 1:1 by the mole ratio method. The calibration graph was linear up to 2.5×10–6 mol/l. The apparent molar absorptivity of the ion associate was 5.3×104 l mol–1 cm–1 (at 595 nm). The relative standard deviation (n=10) for 1.2×10–6 mol/l sodium dodecylsulphate was 4.9%. The proposed method was applied to the determination of anionic surfactants in tap and river waters. 相似文献
9.
Rapid determination of telmisartan in pharmaceuticals and serum by the parallel catalytic hydrogen wave method 总被引:2,自引:0,他引:2
The polarographic characteristics of telmisartan have been investigated in 0.8 mol L–1 NH3.H2O–NH4Cl (pH 8.9)–0.01 mol L–1 H2O2 as supporting electrolyte. The results demonstrate that the polarographic reduction wave at ca. –1.30 V in the absence of H2O2 is a catalytic hydrogen wave, and the reduction wave enhanced by H2O2 is a so-called parallel catalytic hydrogen wave. The analytical sensitivity of the parallel catalytic hydrogen wave is ca. 60 times higher than that of the corresponding catalytic hydrogen wave. Based on the parallel catalytic hydrogen wave a novel method has been developed for determination of telmisartan by linear sweep polarography. The calibration curve is linear in the range 2.0×10–8–2.0×10–6 mol L–1 and the detection limit is 1.0×10–8 mol L–1. The precision is excellent with relative standard deviations of 2.6% at a concentration of 1.0×10–7 mol L–1 telmisartan. The proposed method has been applied to the direct determination of the telmisartan in capsule forms and biological samples. The proposed method has been proved to be advantageous over existing CZE and MEKC methods in simplicity, rapidity, and reproducibility. 相似文献
10.
Micro-pumping flow system for spectrophotometric determination of anionic surfactants in water 总被引:2,自引:0,他引:2
Lavorante AF Morales-Rubio A de la Guardia M Reis BF 《Analytical and bioanalytical chemistry》2005,381(6):1305-1309
A novel procedure has been developed for spectrophotometric determination of anionic surfactants in water using a solenoid micro-pump as fluid-propulsion device. The proposed method is based on substitution of methyl orange (MO) by anionic surfactants in the formation of an ion-pair with the cetyl pyridine ion (CPC+) at pH 5.0. The flow network comprised four solenoid micro-pumps which, under microcomputer control, enabled sample and reagent introduction, and homogenisation in the reaction zone. The system is flexible and simple to operate and control, and sensitive and precise. The analytical plot for the anionic surfactant was linear between 1.43×10–6 and 1.43×10–5 mol L–1 (0.5 to 5.0 mg L–1; R=0.997, n=5). The relative standard deviation was 0.8% (n=11) for a sample containing 5.74×10–6 mol L–1 (2 mg L–1) surfactant. The limit of detection was 9.76×10–8 mol L–1 (0.034 mg L–1) and the sampling throughput was 60 determinations per hour. The results obtained for washing-water samples were comparable with those obtained by use of the reference method, and no significant differences at the 95% confidence level were observed. 相似文献
11.
This paper reports that a red-violet triatomic ion association is formed by protonated 2-(5-bromo-2-pridylazo)-5-diethylamino-o-phenol, IO
3
–
and SCN– in 1.2 mol/l H2SO4. A rapid spectrophotometric flow-injection method has been developed for the determination of IO
3
–
based on the association reaction. Various parameters were optimized. The method is applied to kelp solution and satisfactory results were obtained. The limit of detection for IO
3
–
is 6.0 × 10–7 mol/l with a sample throughput rate of 84 h–1. 相似文献
12.
Some N-alkyl-naphthylazo pyridinium salts as new reagents for the spectrophotometric determination of anionic surfactants 总被引:1,自引:0,他引:1
Summary Eleven pyridinium azo dyes with straight-chain alkyl groups CnH2n+1–(n=6–18) and bromoalkyl groups BrCmH2m–(m=6–12) were synthesized with the intention of developing reagents for the determination of low levels of anionic surfactants in an aqueous medium. The effect of the alkyl chain length of these reagents on the reactivity with anionic surfactants such as sodium dodecylsulphate (SDS), sodium linear-dodecylbenzenesulphonate (DBS), sodium dodecylsulphonate (DS) and sodium laurate (SL) was studied. It was found that the alkyl chain length played an important role in the formation of ion associates and the composition of the ion associates formed. These reagents were classified into four groups with respect to the reactivity with anionic surfactants. The first group (n,m=6) reacts only with DBS. The second group (n,m=8) reacts with SDS, DBS and DS. The third group (n,m=10, 12) reacts with SDS, DBS and DS; however, the colour intensity of the DBS-ion associate was unstable. The fourth group (n=14, 16, 18) reacts with all anionic surfactants examined, and the composition of the ion associates with SDS and DS was 2:1 ([reagent]/[surfactant]) though that of the ion associates of the three reagent groups mentioned above was 1:1. The optimal conditions for the determination of anionic surfactants in river water with 1-octyl-4-(4-aminonaphthylazo)-pyridinium bromide was examined. The calibration graph was linear up to 3×10–6 mol/l, and the apparent molar absorptivity of the ion associate was 3.8×104 l mol–1 cm–1 (at 427 nm). The relative standard deviation for 2.4×10–6 mol/l SDS was 4.9%. Recoveries of 88–107% were found for 8.0×10–7 mol/l SDS in river water samples. 相似文献
13.
Rastislav Serbin Yaroslav R. Bazel Marcel Torok Josef Havel Ioseph S. Balogh Zholt O. Kormosh Gabriela Holéczyová Vasil Andruch 《中国化学会会志》2009,56(6):1168-1174
A new, simple, rapid, sensitive, efficient and low‐cost spectrophotometric procedure for the determination of gold was developed. The method is based on the reaction of [AuCl4]? with 2‐[2‐(4‐dimethylaminophenyl)‐vinyl]‐1,3,3‐trimethyl‐3H‐indolium reagent to form a colored ion associate extractable by various organic solvents. The molar absorptivity of the ion associates is in the range (5.7–9.2) × 104 L mol?1 cm?1 depending on the extractant. Butyl acetate was chosen as the extractant. The optimum reaction conditions were established: pH 2–4, concentration of the dye reagent (0.8–1.5) × 10?4 mol L?1. The determination of gold is not hindered even by a 1000‐fold concentration of Ni and Co; a 500‐fold concentration of Pb and Zn; a 100‐fold concentration of Bi, Cu, Cd, Pt, Rh and Ru; or a 20‐fold concentration of Ag. The established method was applied to the determination of gold in model samples and enriched polymetallic ores. 相似文献
14.
A quantitative analysis method for penicillins including ampicillin (AmP), benzyl penicillin (BP), oxacillin (OA) and amoxycillin (AmO) is proposed that makes use of the totally internally reflected resonance light scattering (TIR-RLS) signal from the penicillin at the H2O/CCl4 interface in the presence of cetyltrimethylammonium bromide (CTMAB), and enables the pharmacokinetics of penicillin taken orally and excreted through urine to be monitored. Penicillin is coadsorbed with CTMAB at the H2O/CCl4 interface in neutral solution, resulting in the formation of ion associates that display greatly enhanced TIR-RLS signals (maximum at 368–372 nm). This enhanced TIR-RLS intensity was found to be proportional to the penicillin concentration over the range 0.2×10–6 to 2.2×10–6 mol L–1, with limits of determination (3) of 5.0×10–8 to 7.0×10–8 mol L–1. Pharmacokinetics studies performed using the present method show that the excretion of orally-taken ampicillin through urine has a half-time of 1.05 h and an excremental quantum over 8 h of 49.3%, respectively. 相似文献
15.
Korolczuk M Moroziewicz A Grabarczyk M 《Analytical and bioanalytical chemistry》2005,382(7):1678-1682
Procedures for trace cobalt determinations by adsorptive stripping voltammetry at in situ and ex situ plated bismuth film electrodes are presented. These exploit the enhancement of the cobalt peak obtained by using the Co(II)–dimethylglyoxime–cetyltrimethylammonium bromide–piperazine-N,N-bis(2-ethanesulfonic acid) system. The calibration graph for an accumulation time of 120 s was linear from 2 × 10–10 to 2 × 10–8 mol L–1. The relative standard deviation from five determinations of cobalt at a concentration of 5 × 10–9 mol L–1 was 5.2%. The detection limit for an accumulation time of 300 s was 1.8 × 10–11 mol L–1. The proposed procedure was applied to cobalt determination in certified reference materials and in tap and river water samples. 相似文献
16.
A novel, simple and environmentally friendly procedure for copper determination has been developed. The method is based on the formation of an ion associate of Cu(I) with 1,3,3-trimethyl-2-[5-(1,3,3-trimethyl-1,3-dihydroindol-2-ylidene)-penta-1,3-dienyl]-3H-indolium (DIDC) in the presence of chloride ions as ligand, followed by dispersive liquid-liquid microextraction (DLLME) of the formed ion associate into organic phase and UV-Vis spectrophotometric detection. The following experimental conditions were used: pH 3, 0.24 mol L− 1 chloride ions, 0.06 mmol L− 1 DIDC. The effect of the nature of the extraction solvent, auxiliary solvent and disperser solvent used was studied. A mixture of amyl acetate, tetrachloromethane, and methanol in a 1:1:3 v/v/v ratio was selected for the DLLME procedure. The absorbance of the coloured extracts at 640 nm wavelength obeys Beer's law in the range 0.020-0.090 mg L− 1 of Cu. The limit of detection calculated from a blank test (n = 10) based on 3s is 0.005 mg L− 1 of Cu. The developed procedure was applied to the analysis of water samples. The suggested DLLME is compared with two procedures previously reported from our laboratory based on (1) conventional liquid-liquid extraction, and (2) sequential injection extraction performed in a dual-valve sequential injection system. The advantages and disadvantages of each method are discussed. 相似文献
17.
G. V. Grishina E. L. Gaidarova A. É. Aliev 《Chemistry of Heterocyclic Compounds》1992,28(10):1166-1174
The asymmetric Michael alkylation of (–)-1,2,5-trimethyl-4-(1S-phenylethylimino)piperidine by electrondeficient alkenes proceeds with the formation of(+)-cis-(2S,5S)- and (–)-trans-(2R,5S) diastereomers of 1,2,5-trimethyl-5-(2-cyanoethyl)- and 1,2,5-trimethyl-5-(2-methoxycarbonylethyl)-4-piperidinones containing a chiral quaternary center C(5). The spatial structure of these new chiral 4-piperidinones has been established on the basis of 1H and 13C NMR spectroscopic data. The absolute configuration of the C(2) and c(5) chiral centers in the diastereomers has been determined by stereochemical correlation on the basis of circular dichroism data.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1369–1378, October, 1992. 相似文献
18.
A rapid and sensitive spectrophotometric method for the simultaneous determination of sodium dodecyl sulphate (SDS) and sodium linear-dodecylbenzenesulphonate (DBS) with 1-stearyl-4-(4-aminonaphthylazo)-pyridinium bromide (SAPB) is described using the difference at the maximum absorption wavelength of the SDS- and the DBS-ion associate. SDS and DBS have been determined independently by measuring their respective absorbances at the maximum absorption wavelength. The apparent molar absorptivities of the SDS- and the DBS-ion associate are 8.0×104 l mol–1 cm–1 at 445 nm and 4.5×104 l mol–1 cm–1 at 424 nm, respectively. The calibration graph for SDS is linear in the range from 0.1 to 1.0×10–6 mol/l in the presence of 1.2×10–6 mol/l DBS and for DBS from 0.8 to 2.0×10–6 mol/l in the presence of 8.0×10–7 mol/l SDS. The relative standard deviation (n=15) for 8.0×10–7 mol/l SDS is 3.4% and for 1.6×10–6 mol/l DBS 2.1%. The proposed method has been applied to the simulatenous determination of SDS and DBS in river water samples. 相似文献
19.
A. A. Tolmachev L. N. Babichenko I. V. Komarov S. V. Sereda A. K. Sheinkman 《Chemistry of Heterocyclic Compounds》1992,28(2):148-153
The compound 1,3,3-trimethyl-2-formylmethyleneindoline oxime is synthesized for the first time. Using the polynuclear resonance method it is shown that the oxime exists as two isomers, one of which has a cyclic structure. A number of reactions are carried out involving the carbocyclic and oxime parts of the molecule.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 183–189, February, 1992. 相似文献
20.
The products of ascorbic acid oxidation in the presence of cobalt octa-4,5-carboxy-phthalocyanine sodium salt (TPH) were identified. These include the ascorbate radical (A·), hydroxyl radical (OH·), and hydrogen peroxide (H2O2). The kinetics of accumulation and consumption of the reaction products was studied. For the concentration ranges of ascorbic acid
= 0–2.5 ⋅ 10−3 mol L−1 and the catalyst C
TPH = 0–3.5 ⋅ 10−5 mol L−1, the the highest possible concentration of the ascorbate radical is ∼10−7 mol L−1, the concentration of H2O2 is 7 ⋅ 10−4 (30% of the starting concentration of ascorbic acid) and the concentration of the hydroxyl radical is at most 10−6 mol L−1.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2224–2228, October, 2004. 相似文献