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Abstract
Electrochemical measurement methods are suitable for examining the hydrolysis and reactivity of chloramine T. The individual species can be separated by means of capillary electrophoresis. Voltammetrical methods make it possible to judge selectively on the oxidation efficiency of individual substances. By coupling the coulometric determination with sample preparation techniques, e.g., stripping out, volatile chlorine can also be determined. The stability of chloramine T solutions was tested at various pH values and hydrolysis reactions are described. It is shown that chloramine T differs from other active chlorine donors and hypochlorite/chlorine with regard to its reactivity.
... Its concentration was established as 0.1% (w/v). With higher concentrations, the reagent precipitates in this pH value, due to the formation of dichloramine-T [25]. With lower concentrations low signal/noise ratio was observed, thus impairing the analysis. ...
... Concerning the reactor length, no significant difference was observed in peak height between the lengths of 0 and 250 cm. However, with no reactor at all, results presented very high coefficient of variance (cv > 15%) and with reactors longer than 200 cm a higher baseline values was observed, probably due to the products formed on the chloramine-T disprotionation [25]. In order to improve precision and establish a low and stable base line a 50-cm reaction coil was then selected. ...
A simple flow-based procedure with chemiluminescence (CL) detection is proposed for bromide ion determination in seawater. The procedure was based on the oxidation of bromide to bromine by chloramine-T followed by the reaction of bromine with luminol resulting in CL emission. Since no significant reaction within chloramine-T and luminol was observed, the detection was carried out without bromine extraction from the oxidant medium. The proposed flow system had a sampling rate of 40 determinations per hour, reagents consumption of 100 μg luminol and 60 μg chloramine-T per determination, a limit of detection of 0.5 mg l−1 bromide ions, a linear concentration range (r = 0.999 and n = 7) between 0 and 100 mg l−1, and a coefficient of variance better than 2.5% (for 10 measurements of a 10 mg l−1 Br− solution) were achieved. The analytical system was applied for the determination of bromide in seawater and estuarine-water samples, obtaining an analyte recovery ranging from 94 to 102% and comparing the results with a reference spectrophotometric method no significant difference was observed in 95% confidence level.
... Alcohols and aldehydes as well as chlorine-containing compounds such as recalcitrant chlorophenols are used as active ingredients. Others release chlorine (see Section 2.6) e.g., chloramine T which exhibits a lower AOX-forming potential (Hahn et al., 1994). Quaternary ammonium compounds (QACs) are cationic microbicidal compounds which are important ingredients of widely used disinfectants for disinfection of surfaces (Russell et al., 1992 ). ...
... An additional AOX in the wastewater will result. According to the literature, the AOX formation through chloramine T is, however, substantially lower than through other elementary chlorine formers such as sodium hypochlorite (Hahn et al., 1994). 4±6% of the latter generate AOX (Schulz and Hahn, 1997). ...
After administration, pharmaceuticals are excreted by the patients into wastewater. Unused medications are sometimes disposed of in drains. The drugs enter the aquatic environment and eventually reach drinking water if they are not biodegraded or eliminated during sewage treatment. Additionally, antibiotics and disinfectants are supposed to disturb the wastewater treatment process and the microbial ecology in surface waters. Furthermore, resistant bacteria may be selected in the aeration tanks of STPs by the antibiotic substances present. Recently, pharmaceuticals have been detected in surface water, ground water and drinking water. However, only little is known about the significance of emissions from households and hospitals. A brief summary of input by different sources, occurrence, and elimination of different pharmaceutical groups such as antibiotics, anti-tumour drugs, anaesthetics and contrast media as well as AOX resulting from hospital effluent input into sewage water and surface water will be presented.
... HClO (Hahn et al, 1994 hydrolysis kill these microorganisms in both aer-50 obic and anaerobic environments quickly, even 51 at low concentrations. Because of the irrevers-52 ibility of these processes, it is difficult for these 53 microorganisms to develop resistance to this 54 active principle. ...
6 Purpose: The aim of the present study was to evaluate the clinical efficacy of an experimental dentifrice (CH) containing 7 an antimicrobial agent (1% Chloramine-T). 8 9 Materials and Methods: A clinical, fully randomised, double-blind comparative study was designed for 30 selected 10 patients aged 15 to 50 years, with no periodontal disease, decay or other oral diseases, good general health and the 11 presence of dental plaque and sulcus gingival bleeding. Baseline Turesky modified plaque index (PI) and sulcus gingival 12 bleeding index (SBI) were scored for all patients. Volunteers randomly received the experimental product (CH) or a 13 commercial-brand dentifrice containing triclosan (TR). Both dentifrices were provided in identical, number-labelled tubes, 14 and the subjects were instructed to use the supplied dentifrice only for their usual oral hygiene, three times a day for a 15 duration of 7 days. After 7-day use of dentifrices, the PI and SBI were assessed again. The data obtained were subjected 16 to the Kruskal–Wallis test, followed by Dunn's post hoc test. 17 18 Results: After 7-day use of dentifrices, the PI scores diminished significantly for both evaluated dentifrices. The SBI 19 score values decreased significantly for both experimental and commercial-brand dentifrices. 20 21 Conclusions: Both dentifrices reduced PI and SBI. By comparing the experimental and gold-standard dentifrice, it was 22 found that there was no statistical difference between the PI and SBI scores after their use, suggesting that they exerted 23 a similar effect on the oral health indexes. 24
... HClO (Hahn et al, 1994 hydrolysis kill these microorganisms in both aer-50 obic and anaerobic environments quickly, even 51 at low concentrations. Because of the irrevers-52 ibility of these processes, it is difficult for these 53 microorganisms to develop resistance to this 54 active principle. ...
The aim of the present study was to evaluate the clinical efficacy of an experimental dentifrice (CH) containing an antimicrobial agent (1% chloramine-T).
A clinical, fully randomised, double-blind comparative study was designed for 30 selected patients aged 15 to 50 years, with no periodontal disease, decay or other oral diseases, good general health and the presence of dental plaque and sulcus bleeding. Baseline Turesky modified plaque index (PI) and sulcus bleeding index (SBI) were scored for all patients. Volunteers randomly received the experimental dentifrice (CH) or a commercial-brand dentifrice containing triclosan (TR). Both dentifrices were provided in identical, number-labelled tubes, and the subjects were instructed to use the supplied dentifrice only for their usual oral hygiene, three times a day for a duration of 7 days. After 7-day use of dentifrices, the PI and SBI were assessed again. The data obtained were subjected to the Kruskal– Wallis test, followed by Dunn's post hoc test.
After 7-day use of dentifrices, the PI scores diminished significantly for both evaluated dentifrices. The SBI values decreased significantly for both experimental and commercial-brand dentifrices.
Both dentifrices reduced PI and SBI. By comparing the experimental and gold-standard dentifrice, it was found that there was no statistically significant difference between the PI and SBI scores after their use, suggesting that they exerted a similar effect on the oral health indexes.
... Significantly less mercury than by Tiutol ® is remobilized by the two disinfectants Aseptoclean2 ® and Orotol Ultra ® (p _< 0.05). The difference between Tiutol and Aseptoclean 2 ® is probably eansed by the higher amount of chloramine T, its and the amalgams pH-dependent oxidation power (Hahn et al. 1994, Sob el al. 1991) and by the fact that Aseptoclean 2 ® is a powder and therefore part of the amount used may be retained in the hose system of the aspirator kit.Table 2. Standard reduction potentials of disinfectant components (in volts) and elemental mercury* (We, st and Alprojet D ® are in agreement with results reported earlier (Ktimmerer et al. 1996). S&M marie ® and Green and Clom ® dissolved less mercury than the other disinfectants (p _< 0.05) compared to water and Ascpto¢loan D ® and Ascptoclean DD ®, p _< 0.01 compared to the disinfectants containing highly oxidi~ng agents. ...
Dental aspirator kits are equipped with amalgam separators, which eliminate the particulate matter from the effluent. When the aspirator kits are disinfected, the disinfectant solution is in contact with the separated amalgams over night and over the weekend. Oxidizing components of the disinfectants dissolve mercury from the separated amalgam. The dissolved mercury is released into the environment along with the effluent on the beginning of the following workday. The degree of mercury remobilization depends on the amount and oxidizing power of the disinfectant components. The mercury concentrations measured in the effluent of the aspirator kits after the application of seven different disinfectants were 18.4 micrograms/l-1396 micrograms/l. The emission of mercury by dental aspirator kits is lowered substantially by using disinfectants which contain no oxidizing substances. Disinfecting of dental aspirator kits for hygienic reasons is not necessary. Therefore we propose only cleaning rather than disinfecting dental aspirator kits.
... Sodium N-chloro-p-toluenesulphonamide (chloramine T) is used as a disinfectant against bacteria, viruses and fungi. Hahn et al. [1] studied the stability of N-chloro-ptoluenesulphonamide in aqueous solutions. Over a period of 60 days a loss of N-chloro-p-toluenesulphonamide was found and p-toluenesulphonamide was formed in stoichiometric amounts. ...
A bacterium capable of utilising p-toluenesulphonamide was isolated from activated sludge. The isolated strain designated PTSA was identified as a Pseudomonas sp. using chemotaxonomic and genetic studies. Pseudomonas PTSA grew on p-toluenesulphonamide in a chemostat with approximately 90% release of sulphate and 80% release of ammonium. The isolate was also able to grow on 4-carboxybenzenesulphonamide and 3,4-dihydroxybenzoate but did not grow on p-toluenesulphonate. The transient appearance of 4-hydroxymethylbenzenesulphonamide and 4-carboxybenzenesulphonamide during p-toluenesulphonamide degradation proves oxidation of the methyl group is the initial attack in the biodegradation pathway. Both metabolites of p-toluenesulphonamide degradation were identified by high-performance liquid chromatography-mass spectrometry. 4-Carboxybenzenesulphonamide is probably converted into 3,4-dihydroxybenzoate and amidosulphurous acid. The latter is a chemically unstable compound in aqueous solutions and immediately converted into sulphite and ammonium. Both sulphite and ammonium were formed during degradation of 4-carboxybenzenesulphonamide.
The shortage and pollution of drinking water are becoming severe problems in many parts of the world. Sanitary water supply is a vital issue for human life. For water disinfection, it is essential to control the concentration of free and combined chlorine appropriately. The authors constructed a flow injection analysis (FIA) system to simultaneously determine free and combined chlorine based on the difference in the photolysis reaction rate. The proposed system contained a Y-branch to separate the injected sample solution into light-irradiated and non-light-irradiated channels. The signals derived from the sample solution, divided into these channels, were detected individually with a time difference, and the simultaneous determination with a single sample injection became available. This study demonstrated the simultaneous determination of hypochlorite ion and chloramine T in the mixture using a pair of simultaneous equations based on pre-prepared relationship curves. The analytical results obtained by the proposed system coincided with the added amount in the mix.
After administration, pharmaceuticals are excreted by patients into the aquatic environment via wastewater. Unused medications are sometimes disposed of in drains. The drugs may enter the aquatic environment and eventually reach drinking water, if they are not biodegraded or eliminated during sewage treatment. Additionally, antibiotics and disinfectants are suspected of disturbing the wastewater treatment process and the microbial ecology in surface waters. Furthermore, resistant bacteria may be selected in the aeration tanks of STPs by the present antibiotic substances.
After administration, pharmaceuticals are excreted and released into the aquatic environment via wastewater effluent. Unused drugs are sometimes disposed of down drains, and, unless they are biodegraded or eliminated during sewage treatment, traces may enter the aquatic environment and eventually reach drinking water. It is also hypothesised that antibiotics and disinfectants disturb the wastewater treatment process and the microbial ecology in surface waters. Furthermore, resistant bacteria may be selected in the aeration tanks of STPs by the antibiotic substances present.
A simple and selective flow-injection method for the determination of cysteine and methionine is proposed. The method is based on the reaction of the amino acid with chloramine-T and the subsequent reaction of the excess of chloramine-T with an acidic solution of iodide producing a stoichiometric amount of tri-iodide (diminution of the flow-injection analysis (FIA) peak) which is determined biamperometrically using two platinum electrodes polarized at 100 mV. The calibration graph is linear up to 10 μg ml−1 of cysteine and 30 μg ml−1 of methionine; the limit of detection is 0.06 and 0.1 μg ml−1; the repeatability (also as percent of a series of 70 continuous FIA peaks of 5 μg ml−1 of cysteine or 15 μg ml−1 of methionine) is 1.1 and 0.7 for cysteine and methionine, respectively. The sample throughput is 220 h−1 in both cases. A large study on the influence of foreign substances is performed especially focused on the rest of l-amino acids. The method is applied to the determination of cysteine, methionine and N-acetyl-cysteine, penicillamine and cystine as structurally related compounds in pharmaceutical and veterinary samples. Finally, the proteins methionine enkephalin and oxytocin are determined on the basis of their contents in both amino acids.
This article reviews recent developments in the characterization of antibiotics. Many capillary electrophoretic techniques have been utilized in their analyses, addressing various aspects of quantifying, profiling and monitoring. Sensitive electrochemical and laser-induced fluorescence detection systems have been utilized, demonstrating trace level determinations in clinical settings and in environmental samples. Different sample introduction methods have been explored, enhancing detection sensitivity, or reducing or eliminating sample manipulation prior to injection.
In the present reevaluation of the Cu-Zn system, the ordering in the β phase is described using a two sublattice model, whereas
four sublattices are used to model theγ phase. A self-consistent set of coefficients has been obtained, allowing both the
equilibrium phase diagram and the thermodynamic properties to be calculated in close agreement with experimental observations.
A flow injection assembly for the determination of chloramine-T is proposed. The sample (213 μl) is inserted into the carrier, de-ionized water flowing at 4.1 ml min−1. This carrier merges with a mixture of potassium iodide and sulphuric acid, and the resulting solution flows to the flow cell through a reactor 66 cm long. The chloramine-T oxidises the iodide to tri-iodide. The resulting iodide/iodine ratio is biamperometrically tested. The calibration graph is linear up to 65 μg ml−1 chloramine-T; the limit of detection is 0.5 μg ml−1; the relative standard deviation (r.s.d) of the calibration slope is 2.8% for a series of eight independent calibrations. The r.s.d. of a series of 74 peaks for 40 μg ml−1 chloramine-T) is 0.8%, and the sample throughput 220 h−1. Few foreign substances interfered. The method is applied to pharmaceutical, veterinary and waste water samples.
To evaluate cytotoxicity and bactericidal effects of chloramine-T.
In vitro study of various concentrations and exposure times to preparations containing human fibroblasts or 1.5 x 10 colony forming units per milliliter (CFU/mL) of 3 gram-positive bacteria-Staphylococcus aureus, methicillin-resistant S aureus, and vancomycin-resistant Enterococcus faecalis-and 2 gram-negative bacteria-Escherichia coli and Pseudomonas aeruginosa-with and without fetal bovine serum present.
Percentage reduction of bacterial growth and percentage of viable fibroblasts 48 hours after exposure.
All gram-positive growth was reduced by 95% to 100%, regardless of dose, with or without serum. E coli (gram-negative; with/without serum) was reduced 94% to 100% at antiseptic concentrations of 300 and 400 ppm. At 200 ppm, E coli growth was fully inhibited without serum present and by 50% with serum. P aeruginosa (gram-negative) was not significantly affected under any conditions. At 100 and 200 ppm, cell viability remained greater than 90% under all experimental conditions. A 300-ppm, 3-minute exposure to chloramine-T resulted in cell viability of up to 70%, with longer exposures producing lower viabilities. Serum did not affect cell viability in any condition.
In vitro, chloramine-T at 200 ppm for 5 to 20 minutes was effective against 3 virulent gram-positive bacteria without fibroblast damage. At 300 ppm and 3 and 5 minutes, 30% of fibroblasts were damaged and 95% to 100 % of E coli were inhibited, respectively.
A number of reducible compounds, such as nitrates, nitrites, nitro, nitroso, azoxy compounds, aldehydes, carbon tetrachloride, oximes, and chloramine T, can be determined by reducing them with chromium(II) ion prepared in an aqueous solution in a special vessel and measuring the absorbance of the resulting chromium(III) in the solution. In this reducing process, nitrate and nitrite are reduced to hydroxylamine quantitatively in hydrochloric acid at room temperature; carbon tetrachloride, nitrobenzene, and chloramine T each consume definite amounts of chromium(II) in an acidic medium at room temperature; propionaldehyde and azoxybenzene react with the reagent only in a basic solution; dimethylglyoxime and 1-nitroso-2-naphthol react only under heating at 80 °C in an basic medium. The absorbance of the resulting chromium(III) ion in the presence of the excess chromium(II) is found to obey Beer’s law at the wavelengths of 410–425 nm over the range of 4×10−3–8×10−2 mol/l of chromium(III). This concentration range corresponds to about 10−5–10−4 mol of the reducible compounds mentioned above. A rapid and precise method has been established with few disadvantages.
Zwischen dem Redoxpotential und dem log der Jodkonzentration jodidhaltiger wäßriger Lösungen
besteht unabhängig vom pH-Wert über 3–4 Zehnerpotenzen ein weitgehend linearer Zusammenhang, der eine einfache und genaue quantitative Bestimmung von Jod ermöglicht. Da unter diesen Bedingungen sehr viele Oxydationsmittel äußerst rasch und quantitativ unter Bildung von Jod (bzw. Trijodid) reagieren, kann die Methode sehr vielseitig angewandt werden (z. B. zur Bestimmung von Chlor, Brom, O- und N-Halogenverbindungen, Ozon u. a.).
A new spectrophotometric method for the assay of very small amounts of chloramine-T has been developed using sulfanilamide. This method is simple and accurate within the limits described.
A novel ultraviolet spectrophotometric method for the assay of microgram amounts (1–80 μg/ml) of CAT and CAB in aqueous solution has been developed. The method is highly sensitive, simple, and rapid within the limits of the experimental conditions described. The present method is also applicable for the determination of these two compounds present in a mixture since they have identical λmax and nearly the same ξmmax. The ultraviolet spectra of the compounds have been presented and the values of λmax and ξax are reported.
Flow-injection determination of chloramine-T, dichloramine-T, dibromamine-T, bromamine-T, chloramine-B, dichloramine-B, dibromamine-B, bromamine-B and dichloramine-N in solution, through a spectrophotometric procedure is described. A simplified flow-injection apparatus with a two-channel system is employed. The carrier streams are starch-KI mixture (0.55.0%) and 1 M H2SO4 and are merged before injection of haloamine. A sampling frequency of 280h–1 has been achieved. The effect of reagent concentrations, flow parameters and interferents on the analysis has been investigated. Concentrations of haloamines were in the range of 1–60 ppm.Die spektralphotometrische FIA-Analyse folgender Verbindungen wird beschrieben: Chloramin-T, Dichloramin-T, Dibromamin-T, Bromamin-T, Chloramin-B, Dichloramin-B, Dibroamin-B, Bromamin-B und Dichloramin-N. Ein vereinfachtes 2-Kanal-FIA-Gert wird benutzt. Trgerlsungen sind KI-Strke (5.00.5%) und 1 M Schwefelsure, die vor der Injektion gemischt werden. Ein Probendurchsatz von 280h–1 wurde erreicht. Einflsse von Reagenskonzentrationen, Flieparametern und Strsubstanzen wurden untersucht. Die untersuchten Konzentrationen lagen im Bereich von 1–60 ppm.
Nach theoretischen Errterungen ber die Redoxpotentiale des Ascorbinsure-Dehydroascorbinsure-Systems und Besprechung der mglichen Reduktionsreaktionen werden Vorschriften gegeben zur ascorbinometrischen Bestimmung von Hexacyanoferrat(III), Hexacyanoferrat(II), Dichromat, Permanganat, Jodat, Bromat und Chloramin T im Mikromastab mit Hilfe eines automatischen Mikrotitrators.The reaction between hexacyanoferrate(III) and ascorbic acid has been applied to the ascorbinometric micro-titration of hexacyanoferrate(III), hexacyanoferrate(II), dichromate, permanganate, bromate and iodate ions as well as chloramine T. Titrations are carried out with an automatic titrimeter which records the potentiometric titration curve. Despite the small amounts of ions involved accuracy and precision of these methods are satisfactory.
Aqueous chloramine-T solutions in strongly alkaline medium are quite stable even up to 60 degrees . In 0.2-2 M sulphuric or perchloric acid at 25-30 degrees , there is no loss in titre, but in hydrochloric acid solutions > 0-5M, there is a loss in titre which increases with increase in hydrochloric acid concentration. This is ascribed to oxidation of chloride to chlorine. In the pH range 2.65-5.65 there is a small but reproducible loss in oxidative titre which is maximal at pH 4.7. This is ascribed to side-reactions occurring during partial disproportionation of monochloramine-T to dichloramine-T and p-toluenesulphonamide.
A high pressure liquid chromatographic (HPLC) method for determining chloramine-T (N-chloro-N-sodium-p-toluenesulfonadmie) in foods such as ice cream, minced meat, and shrimp is described. Deproteinized samples are treated with sulfite to convert chloramine-T to p-toluenesulfonamide (p-TSA) and extracted, and HPLC analysis is performed on concentrated extracts. Sample extracts are chromatographed on a reverse phase 10 micrometers Lichrosorb RP-18 column with acetonitrile-water (190), and quantitated by an ultraviolet detector (220 nm) and digital integrator. The relationship between recorded peak area and concentration was linear to 0.600 micrograms p-TSA/microL. The detection limit was 2.5 ng pTSA/microL, corresponding to a chloramine-T concentration of 0.8 mg/kg in samples. Recoveries of added chloramine-T were 88% for ice cream, 73% for minced meat, and 51% for shrimp. Precision data indicate a relative standard deviation of 1.54 and 2.14% for the complete analysis of ice cream with levels of 15 and 63 mg chloramine-T/kg (n = 5 determinations), respectively. The HPLC method was applied to chloramine-T determinations in 62 ice cream, 25 minced meat, and 25 shrimp samples.