scholarly journals The Ionic Associate of Metamizole as an Electrode-Active Component of a PVC Plasticized Membrane Electrode

Chemosensors ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 17
Author(s):  
Sarizhat D. Tataeva ◽  
Kurban E. Magomedov ◽  
Ruslan Z. Zeynalov ◽  
Naida D. Baygishieva ◽  
Viktorya S. Magomedova ◽  
...  
Keyword(s):  
Active Component ◽  
Limit Of Detection ◽  
Membrane Electrode ◽  
Ionic Associate ◽  
Selective Electrode ◽  
Coefficients Of Variation ◽  
Ion Associate ◽  
Phase Functions ◽  
Good Agreement

The technology for manufacturing a film membrane of the metamizole-selective electrode containing ion associate metamizole-octadecylammonium ODAH+MT− as an electrode active component (EAC) has been proposed. The main potentiometric characteristics of the metamizole-selective electrode have been determined. The expediency of the proposed design of the metamizole selective electrode for the determination of metamizole in dosage forms has been substantiated. The best composition of the membrane (wt.%) of the metamizole-selective electrode has corresponded to: ODAH+MT−—5.3; 2-nitrophenyloctylether—63.1; poly(vinyl chloride)—31.6. Electrode-active component in the membrane phase functions as an ion associate ODAH+MT−. Potentiometric characteristics of metamizole-selective electrode have been determined, which corresponded to: linear range 1 × 10−2–1 × 10−4 with limit of detection 4.58 × 10−5 M, electrode function slope −48.5 mV/dec., working interval pH 4.5–7.3, response time 60 s. The potentiometric coefficients of selectivity of the metamizole-selective electrode with respect to various ions have been determined. The possibility of determining metamizole in a medicinal product has been tested. The results of the analyses show good agreement between the two methods (relative error less than 7.0%) with coefficients of variation less than 5% for MT-SE and iodometric methods.

scholarly journals Determination of diclofenac in pharmaceuticals and urine samples using a membrane sensor based on the ion associate of diclofenac with Rhodamine B

2007 ◽  
Vol 5 (3) ◽  
pp. 813-823 ◽  
Author(s):  
Zholt Kormosh ◽  
Iryna Hunka ◽  
Yaroslav Bazel ◽  
Andriy Laganovsky ◽  
Iryna Mazurenko ◽  
...  
Keyword(s):  
Linear Response ◽  
Ion Association ◽  
Pharmaceutical Formulations ◽  
Membrane Electrode ◽  
Selective Electrode ◽  
Response Characteristics ◽  
Potentiometric Response ◽  
Ion Associate ◽  
Potentiometric Analysis

AbstractThe potentiometric response characteristics of a diclofenac selective electrode, based on ion association in different plasticizers, were compared. The sensitivity, working range, detection limit and selectivity of membrane sensors demonstrated significant dependence on the type of plasticizers. The potentiometric unit presented a linear response toward diclofenac concentrations between 1 × 10−5 − 5 × 10−2 mol L−1, with slopes of approximately 60 mV dec−1, and exhibited a response time of 3 s. The potentiometric analysis of sodium diclofenac in pharmaceutical formulations was perfomed by the membrane electrode proposed and compared with the results of potentiometric titration given by the Pharmacopoeia of Ukraine.

Novel palladium(II) selective membrane electrode based on 4-[(5-mercapto-1,3,4-thiadiazol-2-ylimino)methyl]benzene-1,3-diol

2010 ◽  
Vol 75 (5) ◽  
pp. 563-575 ◽  
Author(s):  
Moslem Mohammadi ◽  
Mehdi Khodadadian ◽  
Mohammad K. Rofouei
Keyword(s):  
Limit Of Detection ◽  
Membrane Electrode ◽  
Aqueous Samples ◽  
Selective Determination ◽  
Poly Vinyl Chloride ◽  
Selective Membrane ◽  
Ph Range ◽  
Palladium Content ◽  
Methyl Benzene

A plasticized poly(vinyl chloride) membrane electrode based on 4-[(5-mercapto-1,3,4-thiadiazol-2-ylimino)methyl]benzene-1,3-diol (L) for highly selective determination of palladium(II) (in PdCl42– form) is developed. The electrode showed a good Nernstian response (29.6 ± 0.4 mV per decade) over a wide concentration range (3.1 × 10–7 to 1.0 × 10–2 mol l–1). The limit of detection was 1.5 × 10–7 mol l–1. The electrode has a response time of about 20 s, and it can be used for at least 2 months without observing any considerable deviation from Nernstian response. The proposed electrode could be used in the pH range of 2.5–5.5. The practical utility of the electrode has been demonstrated by its use for the estimation of palladium content in aqueous samples.

scholarly journals A novel online coupling of ion selective electrode with the flow injection system for the determination of vitamin B1

2016 ◽  
Vol 13 (2) ◽  
pp. 458-469
Author(s):  
Baghdad Science Journal
Keyword(s):  
Flow Injection ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
Vitamin B1 ◽  
Pharmaceutical Formulations ◽  
Ion Selective Electrode ◽  
Injection System ◽  
Selective Electrode ◽  
Flow Injection System

A simple, fast, selective of a new flow injection analysis method coupled with potentiometric detection was used to determine vitamin B1 in pharmaceutical formulations via the prepared new selective membranes. Two electrodes were constructed for the determination of vitamin B1 based on the ion-pair vitamin B1-phosphotungestic acid (B1-PTA) in a poly (vinyl chloride) supported with a plasticized di-butyl phthalate (DBPH) and di-butyl phosphate (DBP). Applications of these ion selective electrodes for the determination of vitamin B1 in the pharmaceutical preparations for batch and flow injection systems were described. The ion selective membrane exhibited a near-Nernstian slope values 56.88 and 58.53 mV / decade, with the linear dynamic range of vitamin B1 was 5 x 10-5- 1 x 10-2 and 1 x 10-4-1 x 10-2 mol.L-1, in batch and FIA, respectively. The limit of detection was 3.5 x 10-5 and 9.5 x 10-5 mol.L-1, with the percentage linearity 98.85 and 95.22 in batch and FIA, respectively. The suggested ion selective electrode has been utilized perfection in the determination of vitamin B1 in pharmaceutical formulations using batch and flow injection system, respectively.

scholarly journals A simple spectrophotometric method for the determination of methyldopa using p-chloranil in the presence of hydrogen peroxide

2008 ◽  
Vol 33 (3) ◽  
pp. 7-12 ◽  
Author(s):  
M. A. Gotardo ◽  
L. S. Lima ◽  
R. Sequinel ◽  
J. L. Rufino ◽  
L. Pezza ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Pharmaceutical Formulations ◽  
Limit Of Quantification ◽  
Coefficients Of Variation ◽  
The Common ◽  
Interday Precision ◽  
Sensitive Spectrophotometric Method

A simple, rapid and sensitive spectrophotometric method has been developed for the determination of methyldopa in pharmaceutical formulations. The method is based on the reaction between tetrachloro-p-benzoquinone (p-chloranil) and methyldopa, accelerated by hydrogen peroxide (H2O2), producing a violet-red compound (λmax = 535 nm) at ambient temperature (25.0 ± 0.2 ºC). Experimental design methodologies were used to optimize the measurement conditions. Beer's law is obeyed in a concentration range from 2.10 x 10-4 to 2.48 x 10-3 mol L-1 (r = 0.9997). The limit of detection was 7.55 x 10-6 mol L-1 and the limit of quantification was 2.52 x 10-5 mol L-1. The intraday precision and interday precision were studied for 10 replicate analyses of 1.59 x 10-3 mol L-1 methyldopa solution and the respective coefficients of variation were 0.7 and 1.1 %. The proposed method was successfully applied to the determination of methyldopa in commercial brands of pharmaceuticals. No interferences were observed from the common excipients in the formulations. The results obtained by the proposed method were favorably compared with those given by the Brazilian Pharmacopoeia procedure at 95 % confidence level.

scholarly journals Simultaneous Determination of Some Phenothiazine Derivatives in Human Blood by Headspace Solid-Phase Microextraction and Gas Chromatography with Nitrogen-Phosphorus Detection

2008 ◽  
Vol 91 (6) ◽  
pp. 1354-1362 ◽  
Author(s):  
Natsuko Shinmen ◽  
Xiao-Pen Lee ◽  
Takeshi Kumazawa ◽  
Chika Hasegawa ◽  
Yasuhiro Ishiwata ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Whole Blood ◽  
Solid Phase Microextraction ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Regression Equations ◽  
Phenothiazine Derivatives ◽  
Headspace Solid Phase Microextraction ◽  
Coefficients Of Variation

Abstract Chlorpromazine, levomepromazine, promazine, triflupromazine, and trimeprazine were simultaneously determined in human whole blood and plasma by combining headspace solid-phase microextraction and gas chromatography with nitrogenphosphorus detection. Extraction efficiency for the phenothiazine derivatives was 0.0130.117 for both sample types. Regression equations were linear [correlation coefficient (r) 0.99510.9999] within the range 2.5200 ng/0.5 mL for triflupromazine and trimeprazine, and 6.3200 ng/0.5 mL for chlorpromazine, levomepromazine, and promazine. The limit of detection for each compound was 0.23.9 ng/0.5 mL whole blood and plasma. Intraday and interday coefficients of variation for all phenothiazines in both human samples were commonly <15 and 20, respectively. We also report the determination of levomepromazine in human plasma after oral administration.

scholarly journals Kinetic spectrophotometric determination of Bi(III) based on its catalytic effect on the oxidation of phenylfluorone by hydrogen peroxide

2009 ◽  
Vol 74 (8-9) ◽  
pp. 977-984
Author(s):  
Sofija Rancic ◽  
Snezana Nikolic-Mandic
Keyword(s):  
Hydrogen Peroxide ◽  
Spectrophotometric Determination ◽  
Reaction Rate ◽  
Catalytic Effect ◽  
Limit Of Detection ◽  
Kinetic Method ◽  
Limit Of Quantification ◽  
Kinetic Spectrophotometric ◽  
Good Agreement

A new reaction was suggested and a new kinetic method was elaborated for determination of Bi(III) in solution, based on its catalytic effect on the oxidation of phenyl-fluorone (PF) by hydrogen peroxide in ammonia buffer. By application of spectrophotometric technique, a limit of quantification (LQ) of 128 ng cm-3 was reached, and the limit of detection (LD) of 37 ng cm-3 was obtained, where LQ was defined as the ratio signal: noise = 10:1 and LD was defined as signal 3:1 against the blank. The RSD value was found to be in the range 2.8-4.8 % for the investigated concentration range of Bi(III). The influence of some ions upon the reaction rate was tested. The method was confirmed by determining Bi(III) in a stomach ulcer drug ('Bicit HP', Hemofarm A.D.). The obtained results were compared to those obtained by AAS and good agreement of results was obtained.

Biological Conjugate between Antibody and ZnS Nanoparticles as Probe for Atomic Absorption Spectrophotometry Determination of Estriol

2014 ◽  
Vol 556-562 ◽  
pp. 64-66
Author(s):  
Chun Yan Zhang ◽  
Chuan Tao Wang ◽  
Shu Hao Wang ◽  
Ling Yun Du
Keyword(s):  
Atomic Absorption ◽  
Limit Of Detection ◽  
Water Solution ◽  
Semiconductor Nanocrystals ◽  
Atomic Absorption Spectrophotometry ◽  
Serum Samples ◽  
Absorption Spectrophotometry ◽  
Primary Materials ◽  
Good Agreement

ZnS semiconductor nanocrystals (NCs) were prepared by ways from primary materials of ZnCl2 and Na2S in water solution. Using the synthesized ZnS NCs, a polyclonal antibody-based ZnS-labelled immunosorbent assay for the determination of estriol (E3) was developed with atomic absorption spectrophotometry (AAS) as a detector. An immunoaffinity column was applied to testify conjugation between antibody and ZnS NCs. The linear range for determination of estriol is 40.0~600.0 ng.mL-1, and the limit of detection (LOD) is 10.0 ng.mL-1. Some serum samples have been analyzed with satisfactory results which are in good agreement with those obtained using ELISA. This work suggests the potential application of NCs as biological probes and AAS as detector in nonisotopic immunoassay.

Determination of Ractopamine Hydrochloride in Swine and Turkey Tissues by Liquid Chromatography with Coulometric Detection

1995 ◽  
Vol 78 (6) ◽  
pp. 1394-1402 ◽  
Author(s):  
Michael P Turberg ◽  
Thomas D Macy ◽  
Jerry J Lewis ◽  
Mark R Coleman
Keyword(s):  
Limit Of Detection ◽  
Solid Phase ◽  
Free Base ◽  
Coulometric Detection ◽  
Solid Phase Extraction Cartridge ◽  
Coefficients Of Variation ◽  
Swine Liver ◽  
Ractopamine Hydrochloride ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method is described for determination of ractopamine hydrochloride (LY031537) in swine and turkey tissues. Liver, kidney, muscle, and fat samples were homogenized in methanol. An aliquot of the extract was evaporated, diluted with water, and buffered to pH 10.5 ± 0.5 with sodium carbonate to convert ractopamine hydrochloride to a free base. The free base was extracted from the buffered sample with ethyl acetate. The extract was further purified on a Bond Elut acid-washed silica solid-phase extraction cartridge. After converting the free base back to the salt form with pH 4.5 buffer, analytical separation and quantitation of ractopamine hydrochloride was performed on an IBM C18 column with coulometric detection at +600 mV. The limit of detection of the method was approximately 0.5 ppb as determined in swine liver. Overall recovery levels ranged between 75 and 100% for samples of liver, kidney, muscle, and fat fortified at 1 to 100 ppb. The coefficients of variation ranged from 2 to 18% for samples fortified at 1 to 100 ppb.

Determination of Nitrate in Forages by Using Selective Ion Electrode: Collaborative Study

1986 ◽  
Vol 69 (2) ◽  
pp. 196-198 ◽  
Author(s):  
Michael P Carlson ◽  
Norman R Schneider ◽  
◽  
R Everson ◽  
J Johnson ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Potentiometric Method ◽  
Selective Electrode ◽  
Coefficients Of Variation ◽  
Nitrate Concentrations

Abstract Each of 10 collaborating laboratories analyzed 4 blind duplicate pairs of forage samples for nitrate, by using a potentiometric method. Two forage controls and a 100 000 mg KNO3/L standard were also provided. Nitrate was extracted into an aqueous Al2(SO4)3 solution containing 70 mg KNO3/L and quantitated with a nitrate-selective electrode. Standards were prepared using extracting solution as diluent. Nitrate concentrations in forage samples ranged from <0.50 to 4.35% KNO3. Repeatability coefficients of variation (CV0) ranged from 1.74 to 3.61%, and reproducibility coefficients of variation (CV1) ranged from 6.92 to 7.66%. Mean recovery of a 0.55% KNO3 spike was 94.5%. The method has been adopted official first action.

Improved liquid-chromatographic method for determination of serum cortisol.

1979 ◽  
Vol 25 (7) ◽  
pp. 1293-1296 ◽  
Author(s):  
P M Kabra ◽  
L L Tsai ◽  
L J Marton
Keyword(s):  
Limit Of Detection ◽  
Internal Standard ◽  
Serum Cortisol ◽  
Peak Height ◽  
Reversed Phase ◽  
Column Temperature ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Abstract We describe a specific and precise method for measuring concentrations of cortisol in serum or plasma by liquid chromatography. Cortisol, together with an internal standard, equilenin, is extracted from 1 mL of serum or plasma and analyzed isocratically on a reversed-phase column with a mobile phase of acetonitrile/phosphate buffer (30/70, by vol.), at a flow rate of 2.0 mL/min. The eluted cortisol is detected by its absorption at 254 nm and quantitated by peak height measurements. Each analysis requires no longer than 15 min at the optimum column temperature of 50 degrees C. The lower limit of detection for cortisol is about 2 ng/sample for a standard solution; sensitivity is routinely 5 micrograms/L of serum. Analytical recoveries exceeded 95%, with good day-to-day precision (coefficients of variation between 4 and 7%). Of more than 50 drugs and steroids tested for possible interference, only the steroids cortisone, prednisone, and prednisolone may interfere with the analysis of cortisol.

Sign in / Sign up

Export Citation Format

Share Document