共查询到20条相似文献,搜索用时 234 毫秒
1.
A novel electrochemical sensor for methyl parathion based on silicate– cetyltrimethylammonium bromide nanocomposite film has
been fabricated by electro-assisted deposition onto glassy carbon electrode in one-step via an electrochemical modulation
of pH at the electrode/solution interface to promote controlled gelification of tetraethylorthosilicate sol, and was characterized
with scanning electron microscopy, X-ray diffraction, and electrochemical impedance spectroscopy. The electrochemical sensing
of methyl parathion on the film-modified electrode was investigated applying cyclic voltammetry and square wave voltammetry.
Compared to the unmodified electrode, the shapes of the redox peaks were improved and the peak currents significantly increased.
Experimental parameters such as deposition time, pH value, and accumulation conditions have been optimized. A linear relationship
between the peak current and methyl parathion concentration was obtained in the range from 1.0 × 10−7 to 1.0 × 10−4 mol L−1 with a detection limit of 1.04 × 10 −8 mol L−1 (S/N = 3) after accumulation at 0 V for 120 s. The film electrode shows great promise for determination of methyl parathion in
real samples.
相似文献
2.
A highly selective and sensitive chemiluminescence method for the determination of triclosan is proposed. The method is based
on the phototransformation of triclosan to a light-emitting precursor in the presence of fluorescein in alkaline medium and
the chemiluminescence reaction is then triggered by strong base or oxidants such as N-bromosuccinimide. Based on this reaction an online phototransformation–flow injection manifold was developed, in which the
photoreactor comprises a 150-cm-long × 0.8-mm-i.d. piece of PTFE tubing coiled around a 25-W fluorescent lamp, and the phototransformed
products were then injected into a carrier stream of borate buffer. After mixing with the oxidant stream the produced light
was detected by a photomultiplier. A wide calibration range from 8.0 × 10−8 to 1.0 × 10−4 mol L−1 was obtained under the optimized conditions, and the detection limit was as low as 5.0 × 10−8 mol L−1. The whole process of analysis, including the online phototransformation and subsequent chemiluminescence detection, could
be completed in 6 min. Most of the foreign substances tested showed high tolerance levels, and the proposed method was directly
applied to the determination of triclosan in toothpaste samples without any pre-separation procedure.
Figure Schematic representation of the phototransformation of triclosan and subsequent chemiluminescence reaction 相似文献
3.
A performant reagentless electrochemiluminescent (ECL) detection system for H2O2 is presented, based on an electropolymerized polyluminol film prepared under near-neutral conditions. Such an original polyluminol
electrodeposition is reported for the first time and on a screen-printed electrode (SPE) surface. Electropolymerized luminol
acts as an active luminophore of the electrochemiluminescent reaction, as the monomer does. Polymerization conditions have
been optimized in order to obtain the best ECL responses to H2O2. By performing electrodeposition in a potentiostatic mode, at 425 mV vs. Ag|AgCl, in 0.1 mol L−1 phosphate/0.1 mol L−1 KCl pH 6 and 1 mmol L−1 luminol, with a total charge of 0.5 mC, the linear range for H2O2 detection extends from 7.9 × 10−8 mol L−1 to 1.3 × 10−3 mol L−1. Such performant disposable reagentless easy-to-use miniaturized systems based on SPEs should be applicable to the electrochemiluminescent
detection of many oxidase-substrate compounds.
Figure An original polyluminol electrodeposition process on a screen-printed electrode surface is reported for the first time. The
polymeric structure is demonstrated to behave as an electrochemiluminescent luminophore, allowing disposable reagentless easy-to-use
optical sensors for hydrogen peroxide detection to be designed. 相似文献
4.
We have developed a circular-dichroism thermal lens microscope for UV wavelengths (UV-CD-TLM), for the first time, to realize
sensitive chiral analysis on a microchip. Quasi-continuous-wave phase modulation of a pulsed UV laser was used to generate
left-circularly polarized light and right-circularly polarized light and to detect the generated TL signal amplitude and phase
with a lock-in amplifier. The amplitude and phase were used to determine the concentration and chirality, respectively, of
a sample. The basic principle of UV-CD-TLM for chiral analysis on a microchip was verified by measuring aqueous solutions
of optically active camphorsulfonic acids (CSA). Lower limits of detection (LOD) were calculated at S/N = 2 and were 8.7 × 10−4 mol L−1 (ΔA = 5.2 × 10−6 Abs.) for (+)-CSA and 8.4 × 10−4 mol L−1 (ΔA = 5.0 × 10−6 Abs.) for (−)-CSA. In terms of number of molecules, LODs for UV-CD-TLM were calculated to be 8.7 fmol and 8.4 fmol, respectively.
This is at least three orders of magnitude lower than previously obtained. The applicability of UV-CD-TLM for chiral analysis
on a microchip was verified.
Figure Sensitive chiral analysis by thermal lens microscope (TLM) 相似文献
5.
Rui Gusm?o Cristina Ari?o José Manuel Díaz-Cruz Miquel Esteban 《Analytical and bioanalytical chemistry》2009,394(4):1137-1145
Multivariate curve resolution with alternating least squares (MCR-ALS) has been applied to voltammetric data obtained from
analysis of the competitive binding of cysteine (Cys) and cysteine–glycine (Cys-Gly) by Cd(II) as a first approach towards
mixtures of phytochelatins and related compounds in natural media. From different starting points, the possibilities of formation
of mixed complexes and/or displacements between ligands are investigated. Analysis of the resulting unitary voltammograms
and concentration profiles of the resolved components by MCR-ALS suggests that the strongest ligand (Cys-Gly) is able to displace
the weakest (Cys) from its metal complexes, whereas this does not happen in the opposite direction. On the other hand, no
evidence of Cd mixed-ligand complexes was found.
Figure Differential pulse polarograms measured in the independent titrations of 1 × 10-5 mol L-1 Cys, 1 × 10-5 mol L-1 Cys-Gly, and a mixture of Cys-Gly (0.5 × 10-5 mol L-1) and Cys (1 × 10-5 mol L-1) with Cd2+, at TRIS-HNO3 buffer (0.1 mol L-1 and PH 7.5) in the presence of 0.1 mol L-1 KNO3 相似文献
6.
In the presence of carbonate and uranine, the chemiluminescent intensity from the reaction of luminol with hydrogen peroxide
was dramatically enhanced in a basic medium. Based on this fact and coupled with the technique of flow-injection analysis,
a highly sensitive method was developed for the determination of carbonate with a wide linear range. The method provided the
determination of carbonate with a wide linear range of 1.0 × 10−10–5.0 × 10−6 mol L−1 and a low detection limit (S/N = 3) of carbonate of 1.2 × 10−11 mol L−1. The average relative standard deviation for 1.0 × 10−9–9.0 × 10−7 mol L−1 of carbonate was 3.7% (n = 11). Combined with the wet oxidation of potassium persulfate, the method was applied to the simultaneous determination
of total inorganic carbon (TIC) and total organic carbon (TOC) in water. The linear ranges for TIC and TOC were 1.2 × 10−6–6.0 × 10−2 mg L−1 and 0.08–30 mg L−1 carbon, respectively. Recoveries of 97.4–106.4% for TIC and 96.0–98.5% for TOC were obtained by adding 5 or 50 mg L−1 of carbon to the water samples. The relative standard deviations (RSDs) were 2.6–4.8% for TIC and 4.6–6.6% for TOC (n = 5). The mechanism of the chemiluminescent reaction was also explored and a reasonable explanation about chemical energy
transfer from luminol to uranine was proposed.
Figure Chemiluminescence profiles in batch system. 1, Injection of 100 μL of K2CO3 into 1.0 mL luminol-1.0 mL H2O2 solution; 2-3 and 4-5, Injection in sequence of 100 μL of K2CO3 and 100 μL of uranine into 1.0 ml luminol-1.0 mL H2O2 solution; Cluminol = 1.0 × 10−7 mol/L, CH2O2 = 1.0 × 10−5 mol/L, Curanine = 1.0 × 10−5 mol/L, CK2CO3 = 1.0 × 10−7 mol/L except for 4-5 where CK2CO3 = 1.0 × 10−4 mol/L 相似文献
7.
The simultaneous determination of three isomers of phenylenediamines (o, m, and p-phenylenediamine) and two isomers of dihydroxybenzenes (catechol and resorcinol) in hair dyes was performed by capillary
zone electrophoresis coupled with amperometric detection (CZE–AD). The effects of working electrode potential, pH and concentration
of running buffer, separation voltage, and injection time on CZE–AD were investigated. Under the optimum conditions the five
analytes could be perfectly separated in 0.30 mol L−1 borate–0.40 mol L−1 phosphate buffer (pH 5.8) within 15 min. A 300 μm diameter platinum electrode had good responses at +0.85 V (versus SCE)
for the five analytes. Their linear ranges were from 1.0 × 10−6 to 1.0 × 10−4 mol L−1 and the detection limits were as low as 10−7 mol L−1 (S/N = 3). This working electrode was successfully used to analyze eight kinds of hair dye sample with recoveries in the range
91.0–108.0% and RSDs less than 5.0%. These results demonstrated that capillary zone electrophoresis coupled with electrochemical
detection using a platinum working electrode as detector was convenient, highly sensitive, highly repeatable and could be
used in the rapid determination of practical samples.
Figure Electropherograms obtained from 10 mg mL−1 hair dye sample solutions at a platinum working electrode under optimum CZE–AD conditions: (a) natural black (I), (b) golden: (1) p-phenylenediamine, (2) m-phenylenediamine, (3) o-phenylenediamine, (4) resorcinol, and (5) catechol 相似文献
8.
Self-assembled monolayers (SAMS) of chemisorbed thioglycollate on a gold electrode surface have been used as a base interface
for the electrostatic adsorption of ferrocenium ion. Electrochemical impedance spectra (EIS) and cyclic voltammetry (CV) were
used to evaluate the electrochemical properties of the supramolecular film. The bare gold electrode failed to distinguish
the oxidation peaks of ascorbic acid (AA) and uric acid (UA) in phosphate buffer solution (PBS, pH 7.0), while the ferricinium–thioglycollate
modified electrode could separate them efficiently. In differiential pulse voltammetric measurements, the prepared gold electrode
could separate AA and UA signals, allowing the simultaneous determination of AA and UA. Under optimal conditions and within
the linear range of 1.0 × 10−6 to 5.0 × 10−4 M, the detection limits of AA and UA achieved were 2.0 × 10−7 and 1.0 × 10−7 M, respectively. The applicability of the prepared electrode was demonstrated by measuring AA and UA in human urine without
any pretreatment.
Figure Fabrication process for the modified electrode 相似文献
9.
Tian XJ Song JF Luan XJ Wang YY Shi QZ 《Analytical and bioanalytical chemistry》2006,386(7-8):2081-2086
Molecular wires containing copper(II) (CuMW), in the form of the coordination polymer (Cu(II)4(bpp)4(maa)8(H2O)2).2H2O (bpp=1,3-bis(4-pyridyl)propane, maa=2-methylacrylic acid), and multiwalled carbon nanotubes (CNT) have been combined to
prepare a paste electrode (CuMW/CNT/PE). The voltammetric response of the CuMW/CNT/PE to metformin (MET) was significantly
greater than that of electrodes prepared from other materials, because of both the surface effect of CuMW and CNT and coordination
of MET with the Cu(II) ion in the CuMW. A novel voltammetric method for determination of MET is proposed. In pH 7.2 Britton–Robinson
buffer, using single sweep voltammetry, the second-order derivative peak current for oxidation of MET at 0.97 V (relative
to SCE) increased linearly with MET concentration in the range 9.0 × 10−7–5.0 × 10−5 mol L−1 and the detection limit was 6.5 × 10−7 mol L−1.
Figure When a combination of molecular wires containing copper(II) (CuMW) and multiwalled carbon nanotubes (CNT) was used to prepare
a paste electrode (CuMW/CNT/PE) the voltammetric response to metformin (curve c) was significantly higher than that at a carbon/PE
(curve a) or a CNT/PE (curve b), because of the amplification effect of CNT and CuMW. A novel voltammetric method is proposed
for determination of MET 相似文献
10.
The redox characteristics of the drug domperidone at a glassy-carbon electrode (GCE) in aqueous media were critically investigated
by differential-pulse voltammetry (DPV) and cyclic voltammetry (CV). In Britton–Robinson (BR) buffer of pH 2.6–10.3, an irreversible
and diffusion-controlled oxidation wave was developed. The dependence of the CV response of the developed anodic peak on the
sweep rate (ν) and on depolizer concentration was typical of an electrode-coupled chemical reaction mechanism (EC) in which an irreversible
first-order reaction is interposed between the charges. The values of the electron-transfer coefficient (α) involved in the rate-determining step calculated from the linear plots of E
p,a against ln (ν) in the pH range investigated were in the range 0.64 ± 0.05 confirming the irreversible nature of the oxidation peak. In
BR buffer of pH 7.6–8.4, a well defined oxidation wave was developed and the plot of peak current height of the DPV against
domperidone concentration at this peak potential was linear in the range 5.20 × 10−6 to 2.40 × 10−5 mol L−1 with lower limits of detection (LOD) and quantitation (LOQ) of 6.1 × 10−7 and 9.1 × 10−7 mol L−1, respectively. A relative standard deviation of 2.39% (n = 5) was obtained for 8.5 × 10−6 mol L−1 of the drug. These DPV procedures were successfully used for analysis of domperidone in the pure form (98.2 ± 3.1%), dosage
form (98.35 ± 2.9%), and in tap (97.0 ± 3.6%) and wastewater (95.0 ± 2.9%) samples. The method was validated by comparison
with standard titrimetric and HPLC methods. Acceptable error of less than 3.3 % was also achieved.
Figure In aqueous media at pH 7.6- 8.4, the DPV and cyclic voltammetry of the drug domperidone (I) at GCE showed an irreversible
and diffusion controlled oxidation wave. The values of the electron transfer coefficient (α) involved in the rate determining
step were found in the range 0.64± 0.05 confirming the irreversible nature of the peak. The analysis of the drug in pure form
and in wastewater samples was successfully achieved 相似文献
11.
Arvand M Pourhabib A Shemshadi R Giahi M 《Analytical and bioanalytical chemistry》2007,387(3):1033-1039
Liquid polymer membrane electrodes based on nickel and manganese phthalocyanines were examined for use as anion-selective
electrodes. The electrodes were prepared by incorporating the ionophores into plasticized poly(vinyl chloride) membranes,
which were directly coated onto the surfaces of graphite electrodes. The resulting electrodes demonstrate near-Nernstian responses
over a wide linear range of perchlorate anion (5 × 10−7 to 1 × 10−1 M). The electrodes have a fast response time, submicromolar detection limits (5 × 10−7 M perchlorate), and could be used over a wide pH range of 3.5–10. The influences of lipophilic cationic and anionic additives
on the response properties of the electrodes were investigated. The proposed sensors revealed high selectivity for perchlorate
over a number of common inorganic and organic anions. The highest selectivity was observed for the electrode based on manganese
phthalocyanine in the presence of the lipophilic anionic additive sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate. Application
of the electrodes to determine perchlorate in tap water and human urine is also reported.
相似文献
12.
Gao J Dai H Yang W Chen H Lv D Ren J Wang L 《Analytical and bioanalytical chemistry》2006,384(6):1438-1443
A rapid and convenient method for the determination of furfural is presented that is based upon sequential perturbation of
the Mn(II)-catalyzed B-Z oscillating system with different amounts of furfural using a continuous-flow stirred tank reactor
(CSTR). When the sample was injected, the change in the amplitude and/or period was linearly proportional to the logarithm
of the concentration of furfural over the range 3×10−8∼1×10−5 mol L−1. This method gave a detection limit of 3×10−9 mol L−1 under optimum conditions. Finally, the possible mechanism of furfural perturbation in the oscillating reaction is discussed.
When the furfural was injected into the Mn(II)-catalyzed B-Z oscillating system, the change in the amplitude and/or period
was linearly proportional to the logarithm of the concentration of furfural over the range 3×10−8~1×10−5 mol L−1, with a detection limit of 3×10−9 mol L−1 under optimum conditions.
相似文献
13.
Zhao P Zhu G Zhang W Zhang L Liang Z Zhang Y 《Analytical and bioanalytical chemistry》2009,393(1):257-261
Studies into the interactions between drugs and human serum albumin (HSA) are extremely important for drug discovery, since
HSA behaves as a carrier for external drugs and internal biological molecules. In this paper, to evaluate the pharmacokinetic
and pharmacodynamic properties of dexamethasone (DXM), the interaction between DXM and HSA was studied by capillary electrophoresis–frontal
analysis (CE-FA). According to the Klotz equation, four binding sites between DXM and HSA were obtained, and the average binding
constant was 1.05 × 103 M−1. Furthermore, according to multiple equilibrium theory, based on the assumption that there are two types of binding site,
the binding constant at one site was calculated to be 3.539 × 103 M−1, and the average of the other three was 1.234 × 103 M−1. In addition, to obtain the detailed binding information at each binding site, new equations were deduced by multivariate
regression. The four binding constants of DXM and HSA were calculated to be 5.558 × 101 M−1, 2.158 × 104 M−1, 7.312 × 103 M−1 and 2.043 × 103 M−1, respectively, which is helpful for detailed studies into the interactions between drugs and proteins with multiple binding
sites.
Figure Electropherograms of DXM sodium phosphate and HAS mixtures for different protein to drug concentration ratios, obtained by
CE-FA 相似文献
14.
Garrigosa AM Ariño C Díaz-Cruz JM Esteban M 《Analytical and bioanalytical chemistry》2008,390(2):769-776
The possibilities of anodic stripping voltammetry (ASV) using an alternating current (AC) scan in the stripping step have
been checked through the study of the complexation of cadmium by Suwannee river fulvic acid (SRFA), a reference fulvic acid
from the International Humic Substances Society. Because of the strong electrode adsorption of SRFA, AC mode appears to be
a good approach to the study when proper selection of the phase angle is made. The goodness of AC mode in ASV has been demonstrated,
and the complexation constant of 3.71 ± 0.04 determined is in good agreement with the value of the constant obtained by the
reference technique of reverse pulse polarography. Some particularities of SRFA have been observed, among them its homofunctional
and strongly heterogeneous behaviour in cadmium complexation and the impossibility of avoiding electrode adsorption problems
in ASV measurements at very low metal concentrations.
Figure DP anodic stripping and AC anodic stripping voltammograms at −12° and −65° during the titration of a 10−7 mol L−1 Cd(II) solution with SRFA at pH 7.5 in 0.05 L−1 Tris
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
15.
Garrigosa AM Ariño C Díaz-Cruz JM Esteban M 《Analytical and bioanalytical chemistry》2008,391(6):2209-2218
A comparison of a differential pulse polarographic with a phase sensitive alternating current polarographic study of the Cd-Cys-Gly
and Cd-PC2 systems [PC2 being a phytochelatin of general structure (γ-Glu-Cys)
n
-Gly, with n = 2] has been performed. The chemometric multivariate curve resolution method with alternating least squares was applied
in the experimental data analysis. The results obtained by both polarographic techniques have made it possible to find out
the formation sequences of the complexes and their final stoichiometries. The alternating current polarograms compared with
the differential pulse ones show some differences (a new signal and an important shift of peak potentials), which anyway are
consistent with some of the conclusions obtained by differential pulse polarography. This fact implies that although the alternating
current polarography results need some corrections before data treatment, they provide extra information that complements
the conclusions achieved by differential pulse polarography.
Figure Voltammograms at ACP(−10°), ACP(−65°) and corrected ACP during the titration of a 10−5 mol L−1 Cd(II) solution with PC2 at pH 8.5 in 0.05 L−1 Tris. 相似文献
16.
Two novel N-(2-mercapto-1,3,4-thiadiazol-5-yl)-N′-(4-substituted-arylacetyl) urea compounds have been synthesized, characterized by NMR and MS, and used as self-assembly reagents
to form self-assembled monolayers (SAMs) on Pt electrodes. The modified electrodes were characterized by electrochemical methods.
The electrochemical behavior of p-benzenediol at the SAMs electrodes was investigated. It was found that the electrochemical response to p-benzenediol is controlled by diffusion and can be electrocatalyzed to obtain more symmetrical redox peaks and higher voltammetric
current response at the SAMs electrodes, with a peak separation of 80 mV. For p-benzenediol the process at the SAMs electrodes is quasi-reversible with a rate constant of 0.6742 s−1. The SAMs electrodes have been used to determine p-benzenediol by differential pulse voltammetry. The peak current was linear for concentrations of p-benzenediol in the range 1×10−7−5×10−4 mol L−1 and the detection limit was 4.0×10−8 mol L−1. The SAMs electrodes were used to determine p-benzenediol in real photographic developer and in a synthetic waste water sample; the standard addition recovery was in the
range 96.6–100.4%.
相似文献
17.
A cobalt hexacyanoferrate (CoHCF)-modified graphite paraffin wax composite electrode was prepared by a new approach. An amine-functionalised
graphite powder was used for the fabrication of the electrode. A functionalised graphite paraffin wax composite electrode
was prepared and the surface of the electrode was modified with a thin film of CoHCF. Various parameters that influence the
electrochemical behaviour of the modified electrode were studied by varying the background electrolytes, scan rates and pH.
The modified electrode showed good electrocatalytic activity towards the oxidation of butylated hydroxyanisole (BHA) under
optimal conditions and showed a linear response over the range from 7.9 × 10−7 to 1.9 × 10−4 M of BHA with a correlation coefficient of 0.9988. The limit of detection was 1.9 × 10−7 M. Electrocatalytic oxidation of BHA was effective at the modified electrode at a significantly reduced potential and at
a broader pH range. The utility of the modified electrode as an amperometric sensor for the determination of BHA in flow systems
was evaluated by carrying out hydrodynamic and chronoamperometric experiments. The modified electrode showed very good stability
and a longer shelf life. The modified electrode was applied for the determination of BHA in spiked samples of chewing gum
and edible sunflower oil. The advantage of this method is the ease of electrode fabrication, good stability, longer shelf
life, low cost and its diverse application for BHA determination.
Figure Cyclic Voltammogram of () CoHCF modified electrode, () in presence of 1.9 x 10−5 M of BHA and () bare electrode, () in the presence of 1.9 x 10−5 M of BHA in 1.0 M NaCl, pH 7.0 相似文献
18.
Water-soluble cadmium sulfide (CdS) quantum dots (QDs) capped by mercaptoacetic acid were synthesized by aqueous-phase arrested
precipitation, and characterized by transmission electron microscopy, spectrofluorometry, and UV-Vis spectrophotometry. The
prepared luminescent water-soluble CdS QDs were evaluated as fluorescence probes for the detection of highly reactive hydrogen
selenide ions (HSe− ions). The quenching of the fluorescence emission of CdS QDs with the addition of HSe− ions is due to the elimination of the S2− vacancies which are luminescence centers. Quantitative analysis based on chemical interaction between HSe− ions and the surface of CdS QDs is very simple, easy to develop, and has demonstrated very high sensitivity and selectivity
features. The effect of foreign ions (common anions and biologically relevant cations) on the fluorescence of the CdS QDs
was examined to evaluate the selectivity. Only Cu2+ and S2− ions exhibit significant effects on the fluorescence of CdS QDs. With the developed method, we are able to determine the
concentration of HSe− ions in the range from 0.10 to 4.80 μmol L−1, and the limit of detection is 0.087 μmol L−1. The proposed method was successfully applied to monitor the obtained HSe− ions from the reaction of glutathione with selenite. To the best of our knowledge, this is the first report on fluorescence
analysis of HSe− ions in aqueous solution.
Figure CdS quantum dots as fluorescence probes for the sensitive and selective detection of highly reactive HSe- ions in aqueous
solution 相似文献
19.
Newly developed, simple, low-cost and sensitive ion-selective electrodes have been proposed for determination of some antiepileptic
drugs such as lamotrigine, felbamate, and primidone in their pharmaceutical preparations as well as in biological fluids.
The electrodes are based on poly(vinyl chloride) membranes doped with drug–tetraphenyl borate (TPB) or drug–phosphotungstic
acid (PT) ion-pair complexes as molecular recognition materials. The novel electrodes displayed rapid Nernstian responses
with detection limits of approximately 10−7 M. Calibration graphs were linear over the ranges 5.2 × 10−7–1.0 × 10−3, 1.5 × 10−6–1.0 × 10−3, and 2.6 × 10−7–1.0 × 10−3 M for drug–TPB and 5.8 × 10−7–1.0 × 10−3, 1.8 × 10−7–1.0 × 10−3, and 6.6 × 10−7–1.0 × 10−3 M for drug–PT electrodes, respectively, with slopes ranging from 52.3 to 62.3 mV/decade. The membranes developed have potential
stability for up to 1 month and proved to be highly selective for the drugs investigated over other ions and excipients. The
results show that the selectivity of the ion-selective electrodes is influenced significantly by the plasticizer. The proposed
electrodes were successfully applied in the determination of these drugs in pharmaceutical preparations in four batches of
different expiry dates. Statistical Student’s t test and F test showed insignificant systematic error between the ion-selective electrode methods developed and a standard method. Comparison
of the results obtained using the proposed electrodes with those found using a reference method showed that the ion-selective
electrode technique is sensitive, reliable, and can be used with very good accuracy and high percentage recovery without pretreatment
procedures of the samples to minimize interfering matrix effects.
Figure Structure of lamotrigine, felbanate and primidone 相似文献
20.
A new spectrofluorimetric method was developed for the determination of trace amounts of lecithin using the ciprofloxacin (CIP)–terbium (Tb3+) ion complex as a fluorescent probe. In a buffer solution at pH=5.60, lecithin can remarkably reduce the fluorescence intensity of the CIP–Tb3+ complex at λ=545 nm. The reduced fluorescence intensity of the Tb3+ ion is proportional to the concentration of lecithin. Optimum conditions for the determination of lecithin were also investigated. The linear range and detection limit for the determination of lecithin were 1.0×10−6–3.0×10−5 mol L−1 and 3.44×10−7 mol L−1, respectively. This method is simple, practical, and relatively free of interference from coexisting substances. Furthermore, it has been successfully applied to assess lecithin in serum samples.
相似文献