Ibuprofen Electrode

The electrodes described in the article [68] were based on associative complexes of ibuprofen with ind(lll) tetraphenylporphyrin. Unlike the above-described electrode, these electrodes were based on a polyurethane matrix and PVC plasticized with dibutyl sebacate (DBS). Both electrodes show a deviation close to Nernstian in the range of ibuprofen concentration of 4 x 10 10 M. In general, PVC electrodes reach better 

Another classic electrode for determination of ibuprofen is a sensor with a polymer membrane containing N-trifluoroacetylbenzoic acid heptyl ester, as the neutral vessel, and anionic ion exchanger, 2,3,4-tris(dodecyloxy)benzyltrimethylammonium 

Ibuprofen BMSA electrodes with a pseudo-liquid membrane phase were developed based on associative complexes of ibuprofen with methylotrioctyloammonium cation 

The electrodes described in the second paper [71 ] also show a Nernstian deviation of -58.3 0.7 mV/decade to -60.9 0.7 mV/decade, but a lower detection limit of 3.0 x 10 . The selectivity coefficients for acetate, oxalate, citrate and sulfate ions are respectively lower than for the electrode containing an associative complex of ibuprofen with methyltrioctylammonium cation. The electrodes also show a longer lifetime (approx. 12 months). The electrode [71] was applied for determination of ibuprofen in drug samples (Ibuprofen - tablets, Polfa, Pabianice, Poland Nurofen Forte Express - Reckitt Benckiser Healthcare International Ltd., Great Britain) with accuracy of 0.5-2.6% and high precision (RSD Q.7-5.5%). 

If we compare the above-described electrodes with classic sensors containing polymer membranes with associates in the form of chlorates [72], it can be stated that classic ibuprofen electrodes have similar analytical parameters determined based on a calibration curve (the slope of linear response of 60 mV/decade, linearity range of 10 -10 mol L, detection limit of 4.0-6.0 x 10 mol L ) and similar values of selectivity coefficients. The BMSA electrode containing TOA-IBU has, however, a longer lifetime. All classic electrodes can function properly for approx. 3 months. 

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An interesting ibuprofen electrode was also described [73], in which, instead of ionic associates or Lewis bases, neutral, macrocyclic compounds (cyclodextrins) were used. 

The apparent acid dissociation constants (p s)Ka) of two water-insoluble drugs, ibuprofen and quinine, were determined pH-metrically in ACN water, dimethyl-formamide water, DMSO water, 1,4-dioxane-water, ethanol water, ethylene glycol-water, methanol water, and tetrahydrofuran water mixtures. A glass electrode calibration procedure based on a four-parameter equation (pH = alpha-i- SpcH -i-jH[H+] -i-jOH[OH ]) was used to obtain pH readings based on the concentration scale (pcH). We have called this four-parameter method the Four-Plus technique. The Yasuda Shedlovsky extrapolation p s)K a + log [H2O] = A/epsllon -1- B) was used to derive acid dissociation constants in aqueous solution (pKa). It has been demonstrated that the pK a values extrapolated from such solvent-water mixtures are consistent with each other and with previously reported measurements. The suggested method has also been applied with success to determine the pKa values of two pyridine derivatives of pharmaceutical Interest. Spectrometric, ultraviolet (UV) ... 

These compounds form neutral inclusive complexes, in particular with compounds containing aromatic and heterocyclic groups, which allows applying them as iono-phores. In a polymer membrane plasticized with o-NPOE, lipophilic additives were also placed, in order to ensure the electroneutrality of the membrane. The electrode also shows a Nernstian response in the range of ibuprofen concentration of 10 -10 mol L, low detection limit of 3 x 10 mol Land good selectivity. The precise and reproducible measurement data for ibuprofen determination in water samples and pharmaceutical preparations, Brufen and Ratiopharm (from a local drug store), 96% on average, support its analytical usefulness. 

V.A. Nazarov, E.I. Sokolova, K.A. Andronchik, V.V Egorov, S.A. Belyaev, T.L Yurkshtovich, Ibuprofen-selective electrode on the basis of a neutral carrier, N-trifluoroacetylbenzoic acid heptyl ester, J Anal Chem, 65 (9), 960-963,2010. 

R. Dumkiewicz, J. Lenik, Ion-selective electrode with a pseudoUquid potential creating chcise to determine ibuprofen, Chem. Anal. (Warsaw), 46,31-39, 2001. 

J. Lenik, C. Wardak, Properties of ibuprofen ion-selective electrodes based on the ion pair complex of tetraoctylcunmonium cation, CentEur J Chem, 8 (2), 382-391, 2010. 

J. Lenik, B. Marczewska, C. Wardak, Properties of ion-selective electrodes with polymer membrcuies for ibuprofen determination. Desalination, 163 (1-3), 77-83, 2004. 

Motoc S, Remes A, Pop A et al (2013) Electrochemieal detection and degradation of ibuprofen from water on multi-walled carbon nanotubes-epoxy composite electrode. J Environ Sci 25 838-847... 

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