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Sýs M, Bártová M, Bartoš M, Švancara I, Mikysek T. Shungite (Mineralized Carbon) as a Promising Electrode Material for Electroanalysis. MATERIALS (BASEL, SWITZERLAND) 2023; 16:1217. [PMID: 36770220 PMCID: PMC9919474 DOI: 10.3390/ma16031217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/20/2023] [Accepted: 01/27/2023] [Indexed: 06/18/2023]
Abstract
In this study, two different types of amorphous carbonaceous Precambrian rock, classified as noble elite shungite and black raw shungite, were tested as possible electrode materials of natural origin. Both types were machined into cylindrical shapes to form the corresponding solid electrodes and their physicochemical and electrochemical properties were compared with the standard glassy carbon electrode (GCE). The raw stones were first subjected to microscopic imaging by using scanning electron microscopy and energy-dispersive X-ray spectroscopy, both of which indicated significant differences in their morphology and in the content of impurities. An electrode prototype manufactured from noble elite shungite (EShE) with a carbon content of about 94% (w/w) has offered a very satisfactory electrochemical performance with a nearly identical heterogeneous electron-transfer rate constant of 7.8 × 10-3 cm s-1 for ferro/ferricyanide redox couple, a slightly narrower potential range (~2.1 V) and a relatively low double-layer capacitance (of ca. 50 μF), resulting in low background currents comparable to those at the GCE. In contrast, the second electrode based on black raw shungite (BShE) with a carbon content of ca. 63% (w/w) exhibited markedly worse electrochemical properties and more than four times higher double-layer capacitance, both of which were probably due to the presence of poorly conductive impurities. The whole study has been completed with three different examples of electroanalytical applications, revealing that the first type, EShE, is a more suitable material for the preparation of electrodes and may represent a cheap alternative to commercially marketed products.
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Mikysek T, Stočes M, Vytřas K. Two Novelties in Ion-pair Formation-based Potentiometric Titrations of Anionic Surfactants. ELECTROANAL 2016. [DOI: 10.1002/elan.201600231] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Tomáš Mikysek
- Department of Analytical Chemistry, Faculty of Chemical Technology; University of Pardubice; Studentská 573 CZ-53210 Pardubice Czech Republic
| | - Matěj Stočes
- Department of Analytical Chemistry, Faculty of Chemical Technology; University of Pardubice; Studentská 573 CZ-53210 Pardubice Czech Republic
- Metrohm Česká republika, s.r.o; Na Harfě 935/5c CZ-19000 Praha 9 Czech Republic
| | - Karel Vytřas
- Department of Analytical Chemistry, Faculty of Chemical Technology; University of Pardubice; Studentská 573 CZ-53210 Pardubice Czech Republic
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Ali TA, Mohamed GG, Al-Sabagh A, Migahed M. A New Screen-printed Ion Selective Electrode for Determination of Citalopram Hydrobromide in Pharmaceutical Formulation. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2014. [DOI: 10.1016/s1872-2040(13)60725-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Imoto M, Sakaki T, Osakai T. Sophisticated Design of PVC Membrane Ion-Selective Electrodes Based on the Mixed Potential Theory. Anal Chem 2013; 85:4753-60. [DOI: 10.1021/ac400427p] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Maya Imoto
- Department of Chemistry, Graduate School of Science, Kobe University, Nada, Kobe 657-8501, Japan
| | - Toru Sakaki
- A&T Corporation, 2023-1 Endo, Fujisawa, Kanagawa 252-0816, Japan
| | - Toshiyuki Osakai
- Department of Chemistry, Graduate School of Science, Kobe University, Nada, Kobe 657-8501, Japan
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Khaled E, El-Sabbagh IA, El-Kholy N, Ghahni EA. Novel PVC-membrane electrode for flow injection potentiometric determination of Biperiden in pharmaceutical preparations. Talanta 2011; 87:40-5. [DOI: 10.1016/j.talanta.2011.09.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2011] [Revised: 09/21/2011] [Accepted: 09/22/2011] [Indexed: 11/29/2022]
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Mohamed GG, El-Shahat MF, Al-Sabagh AM, Migahed MA, Ali TA. Septonex-tetraphenylborate screen-printed ion selective electrode for the potentiometric determination of Septonex in pharmaceutical preparations. Analyst 2011; 136:1488-95. [PMID: 21286616 DOI: 10.1039/c0an00662a] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A screen-printed electrode (SPE) was fabricated for the determination of 1-(ethoxycarbonyl)pentadecyltrimethylammonium bromide (Septonex) based on the use of Septonex-tetraphenylborate as the electroactive substance, and o-nitrophenyloctylether (o-NPOE) as the plasticizing agent. The electrode passes a near-Nernstian cationic slope of 59.33 ± 0.85 mV from activity between pH values of 2 to 9 with a lower detection limit of 9×10(-7) M and response time of about 5 s and exhibits an adequate shelf-life of 6 months. The method was applied for the determination of Septonex in pharmaceutical preparations. A percentage recovery of 99.88% was obtained with RSD=1.24%. The electrode was successfully applied in the determination of Septonex in laboratory-prepared samples by direct potentiometric, calibration curve and standard addition methods. Potentiometric titration of Septonex with sodium tetraphenylborate and phosphotungstic acid as a titrant was monitored with the modified screen-printed electrode as an end-point indicator electrode. Selectivity coefficients for Septonex relative to a number of potential interfering substances were determined. The sensor was highly selective for Septonex over a large number of compounds. Selectivity coefficient data for some common ions show negligible interference; however, cetyltrimethylammonium bromide and iodide ions interfere significantly. The analytical usefulness of the proposed electrode was evaluated by its application in the determination of Septonex in laboratory-prepared pharmaceutical samples with satisfactory results. The results obtained with the fabricated sensor are comparable with those obtained by the British Pharmacopeia method.
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Affiliation(s)
- Gehad G Mohamed
- Chemistry Department, Faculty of Science, Cairo University, Giza, Egypt.
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Mohamed GG, Ali TA, El-Shahat MF, Al-Sabagh AM, Migahed MA, Khaled E. Potentiometric determination of cetylpyridinium chloride using a new type of screen-printed ion selective electrodes. Anal Chim Acta 2010; 673:79-87. [PMID: 20630181 DOI: 10.1016/j.aca.2010.05.016] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Revised: 02/08/2010] [Accepted: 05/12/2010] [Indexed: 11/24/2022]
Abstract
A new type of screen-printed ion-selective electrode for the determination of cetylpyridinium chloride (CPC) is presented. These new electrodes involve in situ, modified and unmodified screen-printed ion-selective electrodes for the determination of CPC. The screen-printed electrodes (SPEs) show a stable, near-Nernstian response for 1 x 10(-2) to 1 x 10(-6) M CPC at 25 degrees C over the pH range 2-8 with cationic slope 60.66+/-1.10. The lower detection limit is found to be 8 x 10(-7) M and response time of about 3s and exhibit adequate shelf-life (6 months). The fabricated electrodes can be also successfully used in the potentiometric titration of CPC with sodium tetraphenylborate (NaTPB). The analytical performances of the SPEs are compared with those for carbon paste electrode (CPE) and polyvinyl chloride (PVC) electrodes. The method is applied for pharmaceutical preparations with a percentage recovery of 99.60% and R.S.D.=0.53. The frequently used CPC of analytical and technical grade as well as different water samples has been successfully titrated and the results obtained agreed with those obtained with commercial electrode and standard two-phase titration method. The sensitivity of the proposed method is comparable with the official method and ability of field measurements.
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Affiliation(s)
- Gehad G Mohamed
- Chemistry Department, Faculty of Science, Cairo University, Giza, Egypt.
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Mostafa GAE. s-Benzylthiuronium PVC matrix membrane sensor for potentiometric determination of cationic surfactants in some pharmaceutical formulation. J Pharm Biomed Anal 2006; 41:1110-5. [PMID: 16540278 DOI: 10.1016/j.jpba.2006.02.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2005] [Revised: 02/04/2006] [Accepted: 02/06/2006] [Indexed: 11/15/2022]
Abstract
The construction and characteristic performance of s-benzylthiuronium (s-BT)-PVC membrane sensor responsive for cetylpyridinium chloride (CPC) are described. The sensor is based on the use of s-BT-tetraphenylborate (TPB) ion pair as electroactive material in PVC matrix in presence of dioctylphthalate as solvent mediator. The membrane sensor shows a fast, stable and near Nernstian response for CPC over the concentration range of 6 x 10(-6)-1 x 10(-3)M at 25 degrees C and pH range 6-12 with cationic slope of 57.0+/-0.4. The lower detection limit is 4 x 0(-6)M and the response time is 10-30 s. Selectivity coefficients for CPC relative to a number of different species were investigated, which there is negligible intereferences are caused by most of investigated cations, anions, and some organic compounds. The determination of 2.0-350.0 microg/ml of CPC in aqueous solutions shows an average recovery of 98.8%and a mean relative standard deviation of 1.87% at 64.0 microg/ml. The determination of CPC in mouthwash pharmaceutical solution gave results that compare favorably with those obtained by the British pharmacopoeia method. The s-benzylthiuronium electrode has been utilized as an end point indicator electrode for some precipitation titration reactions involving CPC as titrant.
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Affiliation(s)
- G A E Mostafa
- Microanalytical Laboratory, Applied Organic Chemistry Department, National Research Center, Dokki, Cairo, Egypt.
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Mostafa GA. PVC matrix membrane sensor for potentiometric determination of cetylpyridinium chloride. ANAL SCI 2001; 17:1043-7. [PMID: 11708056 DOI: 10.2116/analsci.17.1043] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A novel cetylpyridinium chloride-selective membrane sensor consisting of cetylpyridinium-ferric thiocyanate ion pairs dispersed in a PVC matrix placticized with dioctylphthalate is described. The electrode shows a stable, near-Nernstian response for 1 x 10(-3)-1 x 10(-6) mol l-1 cetylpyridinium chloride (CPC) at 25 degrees C over the pH range 1-6 with a cationic slope of 57.5 +/- 0.4. The lower detection limit is 8 x 10(-7) mol l-1 and the response time is 30-60 s. Selectivity coefficients for CPC relative to a number of interfering substances were investigated. There is negligible interference from many cations, anions and pharmaceutical excipients; however, cetyltrimethylammonim bromide (CTMAB) interfered significantly. The determination of 0.5-350 micrograms/ml of CPC in aqueous solutions shows an average recovery of 98.5% and a mean relative standard deviation of 1.6% at 56.0 micrograms/ml. The direct determination of CPC in Ezafluor mouthwash gave results that compare favorably with those obtained by the British Pharmacopoeia method. Precipitation titrations involving CPC as titrant are monitored with a CP sensor. The CP electrode has been utilized as an end point indicator electrode for the determination of anionic surfactants in some commercial detergents.
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Affiliation(s)
- G A Mostafa
- Microanalytical Laboratory, Applied Organic Chemistry Department, National Research Center, Dokki, Cairo, Egypt
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Ježková J, Musilová J, Vytřas K. Potentiometry with perchlorate and fluoroborate ion-selective carbon paste electrodes. ELECTROANAL 1997. [DOI: 10.1002/elan.1140091813] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Microdetermination of sulphate and organic sulphur: potentiometric back-titration using simple coated-wire electrodes. Anal Chim Acta 1993. [DOI: 10.1016/0003-2670(93)85277-q] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Cupková V, Sirotková L, Mlynarcík D, Lacko I, Devínsky F. Enhanced biodegradation of a hard bis-quaternary ammonium salt. Folia Microbiol (Praha) 1992; 37:311-4. [PMID: 1452101 DOI: 10.1007/bf02814570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Bacterial strains with a high biodegradation potential were isolated from activated sludge. Their ability to decompose the hard bis-quaternary ammonium salt FB was determined by the method of chemical oxygen demand (COD) in a mineral medium, where the compound FB was the only source of carbon. The COD values were very low after 21 d and in the course of this period they reached zero level twice. The contribution of adsorption to decrease the COD value was small. The maximum COD decrease was accompanied by an increase of cell respiration. It is suggested that FB is effectively decomposed in spite of the fact that according to its structure it is a typical hard detergent.
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Affiliation(s)
- V Cupková
- Faculty of Pharmacy, Comenius University, Bratislava, Czechoslovakia
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Vytřas K. Coated wire electrodes in the analysis of surfactants of various types: An overview. ELECTROANAL 1991. [DOI: 10.1002/elan.1140030416] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Vytřas K, Šimǐčkovǎ-Štajerova B. Potentiometric ion-pair formation titrations of bisquaternary cations: Determination of diquat and paraquat. Anal Chim Acta 1989. [DOI: 10.1016/s0003-2670(00)80917-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Dohnal J, Vytras K, Roubal Z, Zemanová I. Determination of sulphated glycosaminoglycans by automated potentiometric titration with simple coated-wire electrodes. J Pharm Biomed Anal 1989; 7:835-41. [PMID: 2490091 DOI: 10.1016/0731-7085(89)80003-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A method for the determination of sulphated glycosaminoglycans is based on their precipitation with (1-ethoxycarbonyl)pentadecyltrimethylammonium bromide (Septonex), the excess of which is back-titrated with sodium tetraphenylborate. The titration is monitored by a simple coated-wire ion-selective electrode with a plasticized poly(vinyl chloride) membrane on aluminium wire. Under certain conditions the results are almost independent of the relative molecular mass of glycosaminoglycans. The method has been applied to the determination of the active ingredient in the pharmaceutical preparation, heparon injection.
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Affiliation(s)
- J Dohnal
- Department of Analytical Chemistry and Biochemistry, Research Institute of Pharmacy and Biochemistry, Vinohrady, Czechoslovakia
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Affiliation(s)
- J Dohnal
- Department of Analytical Chemistry and Biochemistry, Research Institute for Pharmacy and Biochemistry, Prague, Czechoslovakia
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Abstract
The use of ion-selective electrodes and potentiometric techniques in the analysis of drug substances are reviewed. Sensors for potentiometric measurements, potentiometric ion-pair and complex formation-based titrations, titrants, and applications are discussed. Other potentiometric methods used in the analysis of pharmaceuticals are discussed.
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Affiliation(s)
- K Vytras
- Department of Analytical Chemistry, University of Chemical Technology, Pardubice, Czechoslovakia
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Vytřas K, Kalous J, Šimíčková B, Černá J, Šílená I. Potentiometric titration of palladium(II) halide complex anions based on ion-pair formation. Anal Chim Acta 1988. [DOI: 10.1016/s0003-2670(00)84586-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Martínez-Jiménez P, Gallego M, Valcárcel M. Indirect atomic absorption spectrometric determination of some cationic surfactants by continuous liquid/liquid extraction with tetrathiocyanatocobaltate. Anal Chim Acta 1988. [DOI: 10.1016/s0003-2670(00)85281-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Determination of some ampholytic and cationic surfactants by potentiometric titrations based on ion-pair formation. Anal Chim Acta 1985. [DOI: 10.1016/s0003-2670(00)82955-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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