Fabrication of PVC Enrofloxacin-Selective Electrodes for Estimating Enrofloxacin in Pure Form and as Preparation Formula:

أوجدت هذه الدراسة تطورا" لخصائص الاستجابة الكهروكيميائية للأقطاب الكهربائية الانتقائية للإينروفلوكساسين باستخدام الراسب والمعتمد على إنتاج الفوسفوتونجستيك ,بعد أستخدام مزيج من البولي فاينيل هيدروكلورايد (PVC) وداي بيوتيل فثاليت أوداي بيوتيل فوسفيت كمواد ملدنة. كانت أغشية المتحسسات الناتجة عبارة عن قطب كهربائي إنروفلوكساسين-فوسفوتونجستيك (متحسس1) ENR-DBPH-PTAوالقطب (متحسس2) .ENR-DOP-PTA  الاستجابات الخطية لأقطاب (ENR-DBPH-PTA)  و(ENR-DOP-PTA)  كانت ضمن المديات التركيزية 2.1×10-6- 10-1 و3.0×10-6- 10-2مول .لتر-1على التوالي, والتي تم ملاحظتها لكلا المتحسسين. الانحدارات كانت 0.24±51.61 و39.40±0.16  ملي فولت/حقبة.  ومديات الدالة الحامضية مساوية الى   8.5-2.5و2.0-9.0 التي لوحظت للمتحسسات 1و2 ,على التوالي. أظهرت أجهزة الاستشعار التي تم إنشاؤها معاملات انتقائية هائلة لعقار ENR.كما أظهرت أجهزة الاستشعار المقترحة خصائص علمية مفيدة لتقدير ENR في جرعة الدواء والشكل النقي.This study explored the development and qualities of the response of electrochemical properties of enrofloxacin-selective electrodes using precipitation based on producing phosphotungstic, after utilizing a matrix of polyvinyl chloride (PVC) and dibutyl phthalate or dibutyl phosphate as a plasticizer. The resulting membrane sensors were an enrofloxacin-phosphotungstic electrode (sensors 1) and an ENR-DOP-PTA electrode (sensors 2). Linear responses of (ENR-DBPH-PTA) and (ENR-DOP-PTA) within the concentration ranges of 2.1×10-6-10-1 and 3.0×10-6-10-2 mol. L-1, respectively, for both sensors were observed. Slopes of 51.61±0.24 and 39.40± 0.16 mV/decade and pH ranges equal to 2.5-8.5 and 2.0-9.0 were observed for sensors 1 and 2, respectively. The coefficients of selectivity of the created sensors demonstrated phenomenal selectivity for ENR. The proposed sensors showed useful scientific properties for the assurance of ENR in drug dosage and pure form

Deep Eutectic Solvents Enhance Stability of Ag/AgCl Solid State Miniaturised Reference Electrode

A new class of solid-state miniaturised reference electrodes with a deep eutectic solvent as an alternate enhancement electrode system is described. A simple and accurate stable electrochemical sensor was prepared by developing a conventional reference electrode using an Ag/AgCl planar micro-reference electrode covered with a PVC polymer. A conductive deep eutectic solvent (DES), ethaline, was added in small quantities and mixed with an internal electrolyte to maintain the Cl− ion concentration in the constructed electrode. The fabricated microelectrode showed good stability, reproducibility, and long-term stability against varying concentrations of different ions. The potential response of the fabricated microelectrode was studied under varying concentrations of Cl− ions in the presence of 0.1 to 1.0% DES in a concentrated electrolyte system (20 mM Na2SO4). The stability of the fabricated microelectrode was addressed against Br− and Cl− ions using different inorganic salts, and the potential measurements were found to be insensitive toward all responsive ions. The stability response of the fabricated microelectrode against Cl− ions was optimised in the presence of 1.0% DES. The experimental data showed good agreement with the potential change of the fabricated electrode in the presence of the supporting DES electrolyte. The liquid junction-free PVC solid-state miniaturised reference electrode demonstrated a constant potentiometric measurement over a long period of time. The concentrated supporting DES electrolyte solution (20 mM) exhibited better stability values and was a more suitable fabricated microelectrode than other additive concentrations. The long-term stability of the developed microelectrode displayed a good lifetime and high stability of around 60 days

Evidence supporting an emulsion polymerisation mechanism for the formation of polyaniline

The electropolymerisation of aniline is a well-studied and often used technology. While the mechanism has been investigated in a variety of media these have all concentrated on understanding the process on a molecular level. Anomalies in the electropolymerisation of aniline in four deep eutectic solvents, DESs, using urea, ethylene glycol, glycerol and oxalic acids as hydrogen bond donors with choline chloride led to an investigation of the aniline phase behaviour. It was only with oxalic acid that polymerisation was achieved and adjusting the pH of the other DESs using sulphuric acid did not enable polymer formation suggesting that pH was not the only factor enabling polymer growth. When 10 wt% water was added, polymers could be grown in all the DESs despite negligible change in solution pH. Dynamic light scattering showed that polymer only formed in systems where aniline formed an emulsion. SEM and AFM showed that the polyaniline films were formed of an agglomeration of small particles of the same dimensions as the dispersed monomer phase in solution. This suggests that the droplets of the monomer arrive at the electrode surface where they polymerise. This provides the first evidence that polyaniline grows by an emulsion polymerisation mechanism even in aqueous solutions

Brønsted acidity in deep eutectic solvents and ionic liquids.

Despite the importance of ionic liquids in a variety of fields, little is understood about the behaviour of protons in these media. The main difficulty arises due to the unknown activity of protons in non-aqueous solvents. This study presents acid dissociation constants for nine organic acids in deep eutectic solvents (DESs) using standard pH indicator solutes. The pKInvalue for bromophenol blue was found by titrating the DES with triflic acid. The experimental method was developed to understand the acid-base properties of deep eutectic solvents, and through this study it was found that the organic acids studied were slightly less dissociated in the DES than in water with pKavalues between 0.2 and 0.5 higher. pKInvalues were also determined for two ionic liquids, [Bmim][BF4] and [Emim][acetate]. The anion of the ionic liquid changes the pH of the solution by acting as a buffer. [Emim][acetate] was found to be more basic than water. It is also shown that water significantly affects the pH of ionic liquids. This is thought to arise because aqueous mixtures with ionic liquids form heterogeneous solutions and the proton partitions into the aqueous phase. This study also attempted to develop an electrochemical pH sensor. It was shown that a linear response of cell potential vs. ln aH+could be obtained but the slope for the correlation was less than that obtained in aqueous solutions. Finally it was shown that the liquid junction potential between two reference electrodes immersed in different DESs was dependent upon the pH difference between the liquids