Sito in Italia dove è possibile acquistare la consegna acquisto Viagra a buon mercato e di alta qualità in ogni parte del mondo.

Microsoft word - nikmans.doc

Proceeding of The International Seminar on Chemistry 2008 (pp. 381-384) Usage of some surfactant types as mediator
on cetirizine determination by using square wave voltammetry technique at
carbon paste electrode
Nikmans Hattu1*, Buchari2, Indra Noviandri2, Sadijah Achmad2 1Research Division of Analytical Chemistry of Institut Teknologi Bandung 2Chemistry Study Program of Institut Teknologi Bandung Abstract

Cetirizine is one of antihistamine (H1-receptor antagonist) drugs which many applied in medical and
pharmacy. Allergy prevalence increases recently, so that usage of this drug also increases. Therefore,
monitoring improvement need to be done. Usage of some surfactant types as mediator in increasing
sensitivity of cetirizine determination has been done by using cyclic voltammetry (CV) and square
wave voltammetry (SWV) techniques. The optimum composition of carbon paste electrode is
70:30% for graphite and paraffin, respectively. Potential interval to determination of cetirizine is 0 -
400 mV. Optimization some parameters have also been done to obtain optimum values of
measurement. The research found that optimum values such as accumulation potential, pulse
amplitude, frequency and scan rate are 1 mV, 25 mV, 15 Hz and 15 mVs-1, respectively. Based on
square wave voltammogram, cetyltrimethylammonium bromide (CTAB) shows the best performance
as mediator. The result shows that increase of peak current is equal to 5.01 times as effect of CTAB
Keywords: antihistamine, carbon paste electrode, cetirizine, surfactant, voltammetry
analysis always done to get new methods. The new method is expected to be more practical, quickly, Antihistamine is one of drugs which many applied in modestly but has reliable performance. Voltammetry medical and pharmacy. Besides successfully used in method many applied in electroanalysis to answer this the therapy of allergic diseases, also used as anti- challenge. A Working electrode is important factor in cholinergic, anti-emetic, anti-phlogistic, sedatives, voltammetry method. One of electrode which often anti-serotonin and has local anesthetic activity (Akdis, applied is carbon paste electrode, recently. Electrode, 2000 ; Juniper,, 2005 ; Sicherer & Leung, modified and usage of mediator meant to increase 2005). It’s often used as combination agents in cough measurement response. The mediator which many and cold drugs. Cetirizine is second generation antihistamine. It is described as a long acting non- Usage of surfactants in electroanalysis has many sedating antihistamine with some mast-cell stabilizing reported. Zhang,,(2002) has applied Cetyl- trimethylammonium bromide (CTAB) as mediator on In 3 last decades happened increasing of allergy determination of Adriamycin. Chengguo,, (2004) prevalence. Not less than 22 % of people in the world have also applied CTAB for determination of every year, hit allergy symptoms that reducing Thyroxine at carbon paste electrode, while productivity and quality of life. The kinds of Allergy Shengshui,, (2002), by using modified nafion- are rhinitis allergy, asthma, rhino-conjunctivitis, glassy carbon has determined estrogen compounds dermatitis syndrome and anaphylaxis. The World (estradiol, estrone and estriol). Posac,,(1995), Allergy Organization (WAO) notes more than US$ 20 even impregnation of Triton X-405 has into carbon billion/year had been released just for handling paste for determination of Aceclofenac. The result of rhinitis allergy (Motala, 2005). The many application researches shows improvement of analysis sensitivity of antihistamine and allergy prevalence that is increasing, causes usage of this drug also increases. Based on these facts, in this research has been Therefore, drug monitoring need to be improved. This made carbon paste electrode to determine cetirizine by thing is done that well guarantied drug quality control Determination of cetirizine is done in surfactants Some analytical methods such as chromatography medium. Influence of some surfactant types is studied and spectrophotometry has been applied to determine to obtain the best of surfactants on increasing analysis cetirizine. Even though, development of chemical Proceeding of The International Seminar on Chemistry 2008 (pp. 381-384) is done. All of these measurements apply optimum condition which has been obtained before. Materials and Methods
Results and Discussion
All the electrochemical measurements were carried Cyclic voltammetry of cetirizine at the CPE out with voltammetric analyzer (Epsilon BASi) and voltammograms were recorded with a set of computer The voltammetric responses of 1x10-2 mol/L cetirizine from IBM. A three-electrode system, including carbon in potassium chloride solution at the carbon paste paste as working electrode, a platinum wire as electrode were investigated by using cyclic auxiliary electrode and Ag/AgCl electrode as voltammetry technique. Voltammogram of cetirizine reference electrode, was employed. All potentials (Fig. 1) is measured at certain potential interval. Determination of potential interval meant to know working area which will be applied. In this research, potential interval is applied to identify peak current of 1 x 10-2 mol/L cetirizine is 0.00 V to +0.30 V with In this research using materials such as cetirizine (pharmaceutical grade), potassium chloride, graphite, solid paraffin, copper wire, cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), sodium dodecylbenzene sulfonate (SDBS), and Triton Preparation of carbon paste electrode (CPE) The CPE was prepared by mixing solid paraffin and graphite powder in a small petri dish, and this mixture was then heated and homogenized. After that, the paste was pressed manually into the cavity of the electrode body, and the surface was smoothed against clean paper. Unless otherwise stated, the paste was Figure 1 Cyclic voltammogram of cetirizine
carefully removed prior to pressing a new portion into the electrode after every measurement. Composition Figure 1 shows cyclic voltammogram of cetirizine optimization of CPE is also done to obtain result of at potential interval from 0.00 V to +0.30 V. Oxidation and reduction peak current were located at A 10 mL volume of 0.1 mol/L potassium chloride containing a known concentration of cetirizine was To obtain carbon paste electrode with the best added into the electrochemical cell and purged with performance, optimization of electrode composition is purified nitrogen for 5 minutes to remove oxygen, and done. Composition ratio of graphite versus paraffin is nitrogen gas was passed over the solution during the made in various 50:50, 60:40, 70:30, 80:20, and 90:10 experiment. After cetirizine was accumulated under an %. The result found that the highest peak current is open-circuit for a certain time while stirring the obtained at composition ratio of graphite versus solution, cyclic voltammogram was recorded from 0.00 V to +0.30 V at scan rate, 50 mV/s. All of the measurements carried out at room temperature. Optimum parameter to determination cetirizine by Optimization and influences of surfactants Optimization of parameters in SWV technique is done Optimization of measurement parameter in square to get highest peak current. These parameter are step wave voltammetry technique is done to obtain the best potential (step E, mV), pulse amplitude (mV), performance of analysis, such as accumulation potential, pulse amplitude and frequency. In the same procedure above, influence of some surfactant types to improvement of analysis sensitivity Proceeding of The International Seminar on Chemistry 2008 (pp. 381-384) concentration range (below the critical micelle concentration (CMC)), but the degree of enhancement Figure 2 Composition optimum of the CPE
The potential wave form consists of a square wave of constant amplitude superimposed on a staircase wave form. The current is measured at the end of each half-cycle, and the current measured on Figure 4 Frequency optimization
the reverse half-cycle (ir) is subtracted from the current measured on the forward half-cycle (if) Among these surfactants, the oxidation peak (Fig.3). This difference current (if - ir) is displayed as current of cetirizine is the highest and the background current is the smallest in the presence of low concentration of CTAB. CTAB with hydrophobic C-H chain and hydrophilic head group can adsorb strongly at the surface of the carbon paste electrode via their hydrophobic interactions. Consequently, adsorbed CTAB induces cetirizine to adsorb at the electrode concentration of cetirizine. So the oxidation peak current of cetirizine increases significantly in the presence of CTAB. In the experimental, the CTAB concentration is 1.0 x 10-4 mol/L. Figure 3 Potential wave form for square wave 3.0
The result of optimization of some parameters influencing peak current of analysis is obtained at step potential, pulse amplitude, and frequency were 1 mV, 25 mV and 15 Hz, respectively. Figure 4 shows level of peak current is obtained at various frequencies. The scan rate cannot be directly investigated by the researcher in this technique, and is determined by step potential (step E) x square wave frequency. Thereby, scan rate optimum is obtained at 15 mV/s. Figure 5 Voltamogram of surfactant influence
The influences of surfactants, such as cationic The average peak current on determination of cetirizine in presence of triton X-100, CTAB, SDS (CTAB), anionic surfactant: sodium dodecyl sulfate and SDBS are 2.20, 3.88, 2.88, and 2,62 x 10-6 A (SDS) and sodium dodecyl benzene sulfonate (SDBS) (Fig.6). This research also find that improvement of and nonionic surfactant: triton X-100, on the oxidation peak current of cetirizine in presence of surfactant to peak current of cetirizine were examined. It is peak current of cetirizine without surfactant are 2.84 observed that all these surfactants can improve the times, 5.01 times, 3.72 times, and 3,38 times for oxidation peak current of cetirizine during a certain Proceeding of The International Seminar on Chemistry 2008 (pp. 381-384) respectively. The relative standard deviations (RSD) Acknowledgements
is obtained on determination of cetirizine in presence of surfactants are 0.55% - 2.24% (n=10). This fact The authors would like to thank Direktorat Jenderal shows reproducibility of this method is good to Pendidikan Tinggi Depdiknas RI for the financial References
Akdis, M., K. Blaser, K and C.A. Akdis. 2005. T- Regulatory cells in allergy: novel concepts in the pathogenesis, prevention, and treatment of allergic diseases. J. Allergy Clin. Immunol., Chengguo, H., Q. He, Q. Li, and S. Hu. 2004. Enhanced reduction and determination of trace thyroxine at carbon paste electrode in the presence Juniper, E.F., E. Stahl, R.L. Doty, F.E.R. Simons, D.B. Allen, and P.H. Howarth. 2005. Clinical Figure 6 Histogram of surfactant influence
outcomes and adverse effect monitoring in allergic rhinitis. J. Allergy Clin. Immunol., 115:S390-S413 Conclusions
Motala, C., 2005. News from world allergy day 2005. J.Current Allergy & Clin. Immunol., 18:91 Usage of some surfactant types as mediator in Posac, J.R., M.D. Vazquez, M.L. Tascon, J.A. Acuna, increasing sensitivity of cetirizine determination has C. de La-Fuente, E. Velasco, and S.P. Batanero. been done by using CV and SWV techniques. 1995. Determination of aceclofenac using Potential interval is applied to determination of cetirizine is 0 - 400 mV and the optimum composition conventional & surfactant chemically modified of carbon paste electrode is 70:30% for graphite and carbon paste electrodes. Talanta, 42:293-304. Shengshui, H., K. Wu, H. Yi, and D. Cui. 2002. The research also find that optimum values in Voltammetric behavior and determination of SWV technique such as accumulation potential, pulse estrogens at nafion-modified glassy carbon amplitude, frequency and scan rate are 1 mV, 25 mV, electrode in the presence of cetyltrimethyl- 15 Hz and 15 mV/s, respectively. Based on square ammonium bromide. Anal. Chim. Acta, 464:209- bromide (CTAB) shows the best performance as Sicherer, S.H and D.Y.M. Leung. 2005. Advances in mediator. The result shows that increase of peak current is equal to 5.01 times as effect of CTAB hypersensitivity reactions to foods, drugs, and insects. J. Allergy Clin. Immunol., 116:153-163 Zhang, S., K. Wu, and S. Hu. 2002. Carbon paste electrode based on surface activation for trace adriamycin determination by a pre-concentration and voltammetric methods. Anal.Sci., 18:1089-


Amenorrhea: Evaluation and Treatment TARANNUM MASTER-HUNTER, M.D., University of Michigan Medical School, Ann Arbor, Michigan DIANA L. HEIMAN, M.D., University of Connecticut School of Medicine, Hartford, Connecticut A thorough history and physical examination as well as laboratory testing can help narrow the differential diagnosis of amenorrhea. In patients with primary amenorrhea, the

BRIEF REPORT Generalized Anxiety late-life GAD as a chronic disorder distinct from MDD. (Am J Geriatr Psychiatry 2005; 13:77–80) Disorder in Late Life Lifetime Course and Generalized anxiety disorder (GAD) in elderly Comorbidity With Major persons is highly prevalent1 and positively as-sociated with functional disability and healthcare Depressive Disorder utilization

Copyright © 2010-2014 Medicament Inoculation Pdf