WorldWideScience

Sample records for chloramine-b

  1. Kinetics and Mechanistic Chemistry of Oxidation of Butacaine Sulfate by Chloramine-B in Acid Medium

    International Nuclear Information System (INIS)

    Shubha, Jayachamarajapura Pranesh; Kotabagi, Vinutha; Puttaswamy

    2012-01-01

    Butacaine sulfate is an ester of p-aminobenzoic acid which has been widely used as a local anaesthetic and it is a long standing agent particularly for spinal anaesthesia. For this reason, a kinetic study of oxidation of butacaine sulfate by sodium N-chlorobenzenesulfonamide (chloramine-B or CAB) has been carried out in HClO 4 medium at 303 K in order to explore this redox system mechanistic chemistry. The rate shows a first-order dependence on both [CAB] o , and [substrate] o , and a fractional-order dependence on acid concentration. Decrease of dielectric constant of the medium, by adding methanol, increases the rate of the reaction. Variation of ionic strength and addition of benzenesulfonamide or NaCl have no significant effect on the rate. The reaction was studied at different temperatures and the activation parameters have been evaluated. The stoichiometry of the reaction has been found to be 1:2 and the oxidation products have been identified by spectral analysis. The observed results have been explained by plausible mechanism and the related rate law has been deduced

  2. Oxidation of Tetracaine Hydrochloride by Chloramine-B in Acid Medium: Kinetic Modeling

    Directory of Open Access Journals (Sweden)

    Jayachamarajapura Pranesh Shubha

    2014-01-01

    Full Text Available Tetracaine hydrochloride (TCH is one of the potent local anaesthetics. A kinetic study of oxidation of tetracaine hydrochloride by sodium N-chlorobenzenesulfonamide (chloramine-B or CAB has been carried in HClO4 medium at 303 K. The rate shows first-order dependence on [CAB]o, shows fractional–order dependence on [substrate]o, and is self-governing on acid concentration. Decrease of dielectric constant of the medium, by adding methanol, increased the rate. Variation of ionic strength and addition of benzenesulfonamide or NaCl have no significant effect on the rate. The reaction was studied at different temperatures and the activation parameters have been evaluated. The stoichiometry of the reaction was found to be 1 : 5 and the oxidation products were identified by spectral analysis. The conjugate free acid C6H5SO2NHCl of CAB is postulated as the reactive oxidizing species. The observed results have been explained by plausible mechanism and the related rate law has been deduced.

  3. Kinetic method for determination of iodide ion ultramicroamounts. Kineticheskij sposob opredeleniya ul'tramikrokolichestv iodid-ionov

    Energy Technology Data Exchange (ETDEWEB)

    Barkauskas, Yu K; Ramanauskas, Eh I

    1980-04-03

    A kinetic method for iodides ultramicroamount determination from their catalytic effect on oxidation of malachite green with chloramine B in the presence of acetone at pH 5.78+-0.3 is developed. The induction period of the reaction is determined from a change in the redox potential of the system. The induction period is proportional to the iodides concentration. Determination limit of iodides is equal to 4 ..mu..g iodide per 100 l of solution. More than 10/sup 5/-multiple amounts of K/sup +/, Na/sup +/, NH/sub 4//sup +/, Ba/sup 2 +/, Al/sup 3 +/, Cu/sup 2 +/, Mg/sup 2 +/, SO/sub 4//sup 2 -/, Cl/sup -/, MoO/sub 4//sup 2 -/, NO/sub 3//sup -/, ClO/sub 3//sup -/, IO/sub 3//sup -/, IO/sub 4//sup -/, ClO/sub 4//sup -/, BrO/sub 3//sup -/; 10/sup 5/-10/sup 3/-multiple amounts of Cr/sup 3 +/, Fe/sup 3 +/, Sn/sup 2 +/, S/sup 2 -/, MnO/sub 4//sup -/, NO/sub 2//sup -/ etc. do not interfere with the determination, while 10-multiple amounts of SCN, 0.2-multiple quantities of Ag/sup +/, Hg/sub 2//sup 2 +/ do.

  4. Kinetic method for determination of iodide ion ultramicroamounts

    International Nuclear Information System (INIS)

    Barkauskas, Yu.K.; Ramanauskas, Eh.I.

    1980-01-01

    A kinetic method for iodides ultramicroamount determination from their catalytic effect on oxidation of malachite green with chloramine B in the presence of acetone at pH 5.78+-0.3 is developed. The induction period of the reaction is determined from a change in the redox potential of the system. The induction period is proportional to the iodides concentration. Determination limit of iodides is equal to 4 μg iodide per 100 l of solution. More than 10 5 -multiple amounts of K + , Na + , NH 4+ , Ba 2 + , Al 3 + , Cu 2 + , Mg 2 + , SO 4 2 - , Cl - , MoO 4 2 - , NO 3- , ClO 3- , IO 3- , IO 4- , ClO 4- , BrO 3- ; 10 5 -10 3 -multiple amounts of Cr 3 + , Fe 3 + , Sn 2 + , S 2 - , MnO 4- , NO 2- etc. do not interfere with the determination, while 10-multiple amounts of SCN, 0.2-multiple quantities of Ag + , Hg 2 2 + do

  5. Rates of Decomposition of N-Chloramine Disinfectant Compounds in Aqueous Solutions

    International Nuclear Information System (INIS)

    EI-Bellihi, E.E.

    2009-01-01

    The effect of temperature, ph, and salt effects on the decomposition kinetics of hydrolysis of N-chloramine disinfectant compounds [chloramine-B, chloramine-T, N-chlorosuccinimide (NCS), and 1,3-dichloro-5,5-dimethyl hydantoin (DCDMH or Halane)] in aqueous solutions was studied. The results should that the hydrolytic stability of CB and CT is greater than that of NCS and halane. Using CT, which is practical in use for its long contact times, reduced its initial concentration in aqueous solution from 100 ppm to about 20 ppm after a period of 6 months. The study also showed that the rate of hydrolysis of NCS is almost independent on the H + ions concentration. On the other hand, the rates of hydrolysis of CB and CT depend strongly on the hydrogen ion (H + ) concentration where the kinetic of the reaction changes from zero-order to a first order. The thermodynamic parameters of activation were calculated and showed that the entropies of activation have large negative values due to the increase in electrostriction and in a loss of freedom of the solvent water molecules associated with the separation of ions in the transition state. A linear compensation between ΔH and ΔS suggests that in the pure aqueous solutions, the reaction mechanism is almost the same for all the chloramine compounds under investigation

  6. Powerful colloidal silver nanoparticles for the prevention of gastrointestinal bacterial infections

    International Nuclear Information System (INIS)

    Le, Anh-Tuan; Le, Thi Tam; Nguyen, Van Quy; Tran, Huy Hoang; Dang, Duc Anh; Tran, Quang Huy; Vu, Dinh Lam

    2012-01-01

    In this work we have demonstrated a powerful disinfectant ability of colloidal silver nanoparticles (NPs) for the prevention of gastrointestinal bacterial infections. The silver NPs colloid was synthesized by a UV-enhanced chemical precipitation. Two gastrointestinal bacterial strains of Escherichia coli (ATCC 43888-O157:k-:H7) and Vibrio cholerae (O1) were used to verify the antibacterial activity of the as-prepared silver NPs colloid by means of surface disinfection assay in agar plates and turbidity assay in liquid media. Transmission electron microscopy was also employed to analyze the ultrastructural changes of bacterial cells caused by silver NPs. Noticeably, our silver NPs colloid displayed a highly effective bactericidal effect against two tested gastrointestinal bacterial strains at a silver concentration as low as ∼3 mg l −1 . More importantly, the silver NPs colloid showed an enhancement of antibacterial activity and long-lasting disinfectant effect as compared to conventional chloramin B (5%) disinfection agent. These advantages of the as-prepared colloidal silver NPs make them very promising for environmental treatments contaminated with gastrointestinal bacteria and other infectious pathogens. Moreover, the powerful disinfectant activity of silver-containing materials can also help in controlling and preventing further outbreak of diseases. (paper)