Preparation of a New selective PVC Membrane Electrode for Copper(II) Ion Based on Complex of 1,3-diphenyl-5- (P-nitrophenyl) Formazan as Ionophore with Copper(II).

A new selective PVC (poly vinyl chloride) membrane electrode for Copper(II) ion was prepared depending on a complex of 1,3-diphenyl-5-(P-nitrophenyl) formazan (FM) as ionophore with copper(II). The best performance was obtained by a membrane electrode with the composition: PVC as matrix (32 %), (FM) as ionophore (3 %), DBP (Dibutyl phthalate) as plasticizer (64%), and NaTBP (Sodium tetraphenylborate) as anionic additive (1%). This electrode exhibited a linear potential response to copper(II) in the concentration range 1.0 × 10−6 – 1.0 × 10-1 M with Nernstian slope of 28.23 mV/decade and detection limit down to 7 × 10−7 M, a response time of about 15 secs, and a life time which exceeded two months over a wide range of PH:3-6. The suggested PVC electrode had a high selectivity for copper over a large number of alkaline and alkaline earth ions and some heavy metals ions. Described membrane electrode could be successfully used in analytical measurements by direct potentiometry for the determination of Cu+2 in standard and real sample solutions. تم في هذا البحث تحضير الكترود غشاء بولي ﭬنيل كلوريد (PVC ) جديد انتقائي لأيون النحاس+ Cu2 بالاعتماد على معقد النحاس (II) مع 1 – 3- ثنائي فنيل – 5 –(- p نترو فنيل) فورمازان كمادة فعالة كهركيميائيا , وتبين من خلال الدراسة أن الغشاء ذو التركيب (32%) PVC , 3% مادة فعالة كهركيميائيا , 64% مادة ملدنة DBP (ثنائي بوتيل فتالات), 1% NaTPB  (صوديوم رباعي فنيل بورات) كإضافة هو الافضل, حيث يبدي استجابه جهدية (نيرنيستية) خطية تجاه أيون النحاسCu2+ ضمن مجال خطي واسع( 1.0 × 10-1 - 1.0 × 10-6)  مول/لتر وميل28.23 mv/decade   بحد كشف بحدود 7×10-7 M و زمن استجابة بحدود 15 sec. وزمن حياة طويل يتجاوز الشهرين , كذلك ضمن مجال واسع pH  بين 6 – 3 , وتبين من خلال حساب معاملات الانتقائية باستخدام طريقة الكمون الموافق Matched Potential  Method(MPM),  إن الكترود غشاء PVC المقترح يتمتع بانتقائية عالية لأيونات Cu+2 بوجود العديد من الايونات القلوية والقلوية الترابية وبعض أيونات المعادن الثقيلة الأخرى, واستخدم الالكترود المقترح بنجاح في تحديد تركيز النحاس +Cu2 في عينات قياسية وأخرى واقعية من البيئة المائية . الكلمات المفتاحية : ايون النحاس (II) , ISE , أصبغة الفورمازان , الكترود غشاء PVC ,المعايرة الكمونية

Using PVC ion-selective electrodes for the potentiometric flow injection analysis of distigmine in its pharmaceutical formulation and biological fluids

The construction and electrochemical response characteristics of poly(vinylchloride) (PVC) membrane selective electrodes for the determination of distigmine (Ds) are described. The sensing membrane comprised an ion-pair based on distigmine phosphomolybdate (Ds-PM), distigmine phosphotungstate (Ds-PT), distigmine silicomolybdate (Ds-SM), distigmine silicotungstate (Ds-ST), distigmine tetraphenylborate (Ds-TPB), and distigmine reineckate (Ds-Rein) in a plasticized PVC matrix with dioctylphthalate (DOP). The influence of membrane composition on the electrodes’ response was studied. The electrodes showed a fast, stable and Nernstian response over a wide distigmine concentration range 5.0 × 10−7–1 × 10−2 mol L−1 with a slope of ∼30.5 ± 1.0 mV dec−1. The response is independent of the pH of test solution within the range 3.8–10.5. The life span of the electrodes extends to at least 2 months without any considerable divergence in potential and has a fast response time of <15 s. The electrodes showed good selectivity towards distigmine with respect to large numbers of ions in batch and FIA systems. The electrodes have been applied to the determination of distigmine in pure solution, pharmaceutical compound and human urine. The dissolution profile for Ubretid tablets (5 mg/tablet) was studied

Solid contact sensors for determination of the antihistaminic drug ketotifen fumarate

Reliable potentiometric sensing devices with unique advantages were constructed for determination of ketotifen fumarate (keto-fuma). Five sensors based on Ag, Ag/Ag2S, Ag/AgCl, graphite and glassy carbon solid beds were constructed. These sensors were constructed based on ketotifen-tetraphenylborate (keto-TPB) as ion pairing material and dibutyl phthalate as solvent mediators. The sensors showed high sensitivity and near Nernstian slope in batch and flow injection conditions (FIA). According to the results obtained, the best behavior observed for coated graphite sensor was with slope 60.10 mV·decade–1, linear range 7×10–6–1×10–2 M, and limit of detection 3.9×10–7 M. Enhancement of the detection limit of the sensors was done by incorporating potassium tetraphenylborate (KTPB) and graphite in the membrane. The sensors were used for determination of keto-fuma in the pure form as well as in its pharmaceutical preparations. It was performed using potentiometric titration and standard addition methods with recoveries of 97.0–100.4 % and relative standard deviations of 0.13–1.42 %

Mixed ion-exchanger chemically modified carbon paste ion-selective electrodes for determination of triprolidine hydrochloride

Triprolidine hydrochloride (TpCl) ion-selective carbon paste electrodes were constructed using Tp-TPB/Tp-CoN and Tp-TPB/Tp-PTA as ion-exchangers. The two electrodes revealed Nernstian responses with slopes of 58.4 and 58.1 mV decade−1 at 25 °C in the ranges 6 × 10−6–1 × 10−2 and 2 × 10−5–1 × 10−2 M for Tp-TPB/Tp-CoN and Tp-TPB/Tp-PTA, respectively. The potentials of these electrodes were independent of pH in the ranges of 2.5–7.0 and 4.5–7.0, and detection limits were 6 × 10−6 and 1 × 10−5 M for Tp-TPB/Tp-CoN and Tp-TPB/Tp-PTA, respectively. The electrodes showed a very good selectivity for TpCl with respect to a large number of inorganic cations and compounds. The standard addition, potentiometric titration methods and FIA were applied to the determination of TpCl in pure solutions and pharmaceutical preparations. The results obtained were in close agreement with those found by the official method. The mean recovery values were 100.91% and 97.92% with low coefficient of variation values of 0.94%, and 0.56% in pure solutions, 99.82% and 98.53% with coefficient of variation values of 2.20%, and 0.73% for Actifed tablet and Actifed syrup, respectively, using the Tp-TPB/Tp-CoN electrode, and 98.85%, and 99.18% with coefficient of variation values of 0.48% and 0.85% for Actifed tablet and Actifed syrup, respectively, using the Tp-TPB/Tp-PTA electrode

Colorimetric and Atomic Absorption Spectrometric Methods for the Determination of Hyoscine N-Butylbromide in Pharmaceutical Formulations Using Cobalt (II) and Chromium (III) Thiocyanate Complexes

Two simple and sensitive colorimetric and atomic absorption spectrometric procedures have been established for determination of hyoscine N-butylbromide (Hyo.Br) in pure form and in pharmaceutical formulation. The methods are based on formation of an insoluble coloured ion-associate between the examined drug and tetrathiocyanatocobaltate (CoTC) or hexathiocyanatochromate (CrTC). The first method involves extraction of Hyo-CoTC and Hyo-CrTC ion-associates with methylene chloride and isobutyl alcohol, followed by measuring the absorbance at 630 and 557 nm, respectively. Optimization of the extraction conditions is investigated. Beer\u27s law is obeyed in the concentration ranges 144.20-865.20 and 72.00-640.00 μg/ml using CoTC and CrTC, respectively. The molar absorptivities, Ringbom ranges, Sandell sensitivities and quantification and detection limits are also calculated. The second method is based on measuring the absorbance of the excess cobalt or chromium in the aqueous solution, after precipitation of the drug, at 240.7 and 357.9 nm using atomic absorption spectrometer, respectively. Linear application ranges, characteristic concentrations and detection limits of Hyo.Br are 0.404-1.617 mg/ml, 16.11 and 10.78 μg/ml in the case of CoTC, while 0.040-0.283 mg/ml, 29.50 and 2.70 μg/ml in the case of CrTC. The present methods have been successfully applied for the determination of the drug in commercial dosage form. The data obtained by the developed methods are compared with the official one

Evaluation of Mariut Lake water quality using Hyperspectral Remote Sensing and laboratory works

It would be an advantage if there were a measurement method, which would provide more detailed spatial information on water contaminations at low cost. Hyperspectral Remote Sensing has a possibility for gathering detailed: contamination information rapidly and inexpensively. This study includes the possibility of assessing heavy metal contamination of water in Mariut Lake and predicting models describe their concentration using spectrum data taken by portable FieldSpec_3 ASD Spectroradiometer. The main objectives of this research are assessing water contamination by heavy metal in Mariut Lake using laboratory analysis and developing a predictive model for water pollution based on the spectral characteristics and lab data obtained. It is resulted that Pb, Ni and Cr concentrations exceed permissible limit of USEPA. Also, the spectral reflectance of (6–13, 16, 19 and 20) at wavelength 582–653 nm is related to the spectral behavior of the high chlorophyll concentration. Also there are 7 samples (1, 3, 6, 10, 11, 19 and 21) showed high and low values of turbidity. As the suspended sediment concentration increased, reflectance also increased at all wavelengths between 400 and 850 nm. It is concluded that most of models predicting heavy metals concentration using reflectance spectroscopy have high significant correlation ranged from 0.27 to 0.97

Potentiometric and surface topography studies of new carbon-paste sensors for determination of thiamine in Egyptian multivitamin ampoules

We report here for the first time two potentiometric carbon-paste sensors for determination of thiamine chloride hydrochloride in aqueous solutions. The proposed sensors use the ion-pair of thiamine with tetraphenylborate as an electro-active species and dibutyl phthalate (sensor I) or o-nitrophenyloctyl ether (sensor II) as solvent mediators. The effect of solvent mediator was studied using dibutyl phthalate, o-nitrophenyloctyl ether, ethylhexyl adipate, dioctyl phthalate, tricresyl phosphate and paraffin oil. The slopes of the calibration graphs are 29.49 ± 0.24 and 29.60 ± 0.15 mV/decade for sensors (I) and (II), respectively. The sensors are able to detect down to 5.25 × 10−6 and 3.57 × 10−6 for (I) and (II), respectively. Both sensors show reasonable thermal stability and fast response time. The selectivity coefficients obtained from the matched potential method indicate high selectivity of the proposed sensors toward thiamine over commonly interfering cations. Sensor (I) has a lifetime of only 1–2 days; however, sensor (II) remains usable for up to one month. Analytical applications to pure solutions and Egyptian multivitamin ampoules show excellent recovery values ranging from 97.92 to 103.72% and 97.21 to 102.19% for sensors (I) and (II), respectively. Moreover, the precision and reproducibility of the sensors are indicated from the low values of %RSD of five replicate measurements. In addition, the surface topography of the sensors was studied using scanning electron microscopy to investigate the effect of chemical modification on the surface structure