Determination Of Chlorine In Water Research Articles

Ion Chromatography for Rapid and Sensitive Determination of Total Chlorine in Water

In this article, we report a new method that involves adsorption, oxygen bomb combustion, and ion chromatography for the preconcentration and determination of adsorbable organic halogen. This method can be divided into four steps, including: macroporous resin adsorption enrichment, optimization, oxygen bomb combustion, and ion chromatography determination. The project studies the macroporous resin adsorb organic halide pollutants and subsequent burn by an oxygen bomb combustion analyzer. The organic halogen in the aerobic environment combusts into hydrogen chloride. The water absorbing hydrogen chloride was then determined by ion chromatography. The influences of some adsorption and combustion parameters, such as the adsorption time, adsorption solution volume, solution pH, hexachlorobenzene acid concentration, combustion oxygen pressure, among others, on their respective adsorption efficiency were investigated. In the optimal condition, the adsorption time was 3.5 h; solution volume was 20 mL; pH was 4; combustion absorption time was 15 min; and the chloride calibration working range was from 1 ppm to 20 ppm (R 2 = 0.9998). Finally, the proposed method was successfully applied to the determination of organic halogen in water samples. The recoveries of chlorine (at spiked concentrations of 10 ppm and 20 ppm into water) in real samples ranged from 92.2% to 101.0%. Intra-day precision (N = 3) in terms of peak area, expressed as relative standard deviation, was found to be within the range of 0.68%–1.97%.

Electroanalytical Applications Based on Carbon Nanotube/Prussian Blue Screen-printable Composite

A single step fabrication process of carbon nanotube/Prussian Blue (CNT/PB) paste electrodes based on screen printing technology has been studied as an amperometric sensor for the determination of hydrogen peroxide and free chlorine. Compared to the classical carbon paste (CP) electrode, the CNT paste electrode greatly enhanced the response in the presence of hydrogen peroxide due to the electrocatalytic activity of the CNT. Based on the CNT/binder paste, PB was also incorporated into a network of CNT paste and characterized. The best electroanalytical properties of PB-mixed sensors to hydrogen peroxide were obtained with PB ratio of 10 wt % composition, which showed fast response time (<TEX>$t_{90}{\leq}5$</TEX> s; 0.2 - 0.3 mM), low detection limit of 1.0 <TEX>${\mu}M$</TEX>, good linear response in the range from <TEX>$5.0{\times}10^{-5}$</TEX> - <TEX>$1.0{\times}10^{-3}$</TEX> mol <TEX>$L^{-1}$</TEX> (<TEX>$r^2$</TEX> = 0.9998), and high sensitivity of -8.21 <TEX>${\mu}AmM^{-1}$</TEX>. In order to confirm the enhanced electrochemical properties of CNT/PB electrode, the sensor was further applied for the determination of chlorine in water, which exhibited a linear response behavior in the range of 50 - 2000 ppb for chlorine with a slope of 1.10 <TEX>${\mu}Appm^{-1}$</TEX> (<TEX>$r^2$</TEX> = 9971).

Optochemical Film Sensor for the Determination of Free Chlorine in Water

An thin reagent containing optochemical film sensor for detecting and measuring free chlorine in water is described. The film sensor has been manufactured by immobilisation indicator of 3,5-dimethyl-4-hydroxybenzaldazine in a permeable transparent polymeric membrane. A linear calibration for free available chlorine can be obtained in the range between 0.05 and 3ppm. The limit of quantitation is 0.3 ppm, and the accuracy exceeds 7%. It takes about 150s to measure the relatively low occupational exposure concentration of 0.1ppm. The interference of combined chlorine has been studied. The sensor has no response to combined chlorine. And the stability of the sensors and the effect of external parameters like relative humidity (RH), temperature on the sensor response have been investigated. The sensor response is affected by varying the temperature; however, humidity in the range between 0 and 90% RH does not affect sensor response. The 3,5-dimethyl-4-hydroxybenzaldazine remained stable inside the polymeric film and no chemical reaction, crystallization or leaching occurred during 6 months of observation. Proper choice of indicator dye and polymeric material and successful application of kinetic evaluation method for the exposure experiments determine the desired features of the sensor. Introduction

A new water-soluble chromogenic indicator: an application to the determination of chlorine in aqueous solutions.

A novel compound, N,N'-bis(2,4-di-sulfobenzyl)tolidine tetrasodium salt (SBT), was synthesized for use as a chromogenic indicator for oxidizing substances, and its applicability to the colorimetric determination of chlorine in water was examined.

Comparison of Methods and Kits for Colorimetric Determination of Residual Chlorine in Water

Abstract The use of 3,3',5,5'-tetramethylbenzidine (TMB) for residual chlorine determination in water offers 2 possibilities, one at pH 1-2 and absorbance measurement at 450 nm and another at pH 3.8-5.8 and measurement at 650 nm. The reaction of chlorine with TMB reaches its maximum sensitivity at pH 1-2. The detection limit is 2 ng/mL. A calibrated scale for colorimetric determination of residual chlorine in water with 3,3',5,5'-tetramethylbenzidine (TMB), prepared with tropaeolin O (C.I. 14270), is described. This scale is stable for several months and can be useful in replacing the conventional and much less stable scale prepared from standard solutions of oxochlorate (I). Kits for determination of residual chlorine in water by visual comparison, including a 3-dimensional scale or a color scale printed on paper or a plastic material, are described in this article. A comparative study of the analytical qualities and applications of the TMB methods against other reagents methods is performed.

A Fluorescence Quenching Method for the Determination of Chlorine in Water with 2,3,7-Trihydroxy-9-Dibromo-Hydroxy-Phenylfluorone and Cetyltrimethylammonium Bromide

Abstract A highly sensitive and selective fluorescence quenching method was developed to determine chlorine with 2,3,7-trihydroxy-9-dibromo-hydroxy-phenylfluorone as fluoregenic reagent. In the presence of CTMAB, a red compound was produced, its maximum excitation wavelength is 495nm, its emission wavelength is 520nm. The detection limit is 0.10μg/25ml. The linear calibration range is 0.10–3.0μg/25ml. This method may be used for the determination of chlorine in water.

Pneumatoamperometric determination of chlorine in water

Free chlorine in water can be determined by acidifying the water sample, purging it with nitrogen and determining the chlorine present in the nitrogen stream with a gold porous electrode. The current response of gold porous electrode is related to the concentration of free chlorine by using a calibration curve. This pneumatoamperometric method gives results fully comparable to the standard o-toluidine photometric method used for water supplies. It is uninfluenced by the presence of other dissolved oxidants and requires only one milliliter of sample.

Communication. Stabilisation of DPD (N,N-dimethyl-p-phenylenediamine sulphate) reagent for the determination of free available residual chlorine in water

Communication. Stabilisation of DPD (N,N-dimethyl-p-phenylenediamine sulphate) reagent for the determination of free available residual chlorine in water

Determination of chlorine in water by luminol chemiluminescence

Determination of chlorine in water by luminol chemiluminescence

The absorptiometric determination of chlorine in water

The absorptiometric determination of chlorine in water

Determination of Chlorine in Water

Determination of Chlorine in Water

Photodiscoloration of Orthotolidine and Artificial Standards for Free Chlorine Test in Water

As deterioration of the reagent used may seriously affect the accuracy of the determination of free chlorine in water, it seemed important to find out whether the discoloration and precipitate which we have observed in orthotolidine on its exposure to sunlight actually impaired its value. Ellms and Hauser (1) have found that the reagent does not deteriorate on standing; they do not mention the effect of direct sunlight, however, or of other extreme conditions. In order to ascertain this, one liter of orthotolidine solution was divided in half and put into clear glass bottles. One portion was exposed to south light and the other was stored in a dark cupboard. These two solutions were used at various intervals in free chlorine determinations. The color of the ortholidine reagents was also observed. The results of these observations are given in table 1. The reagent exposed to the light showed a discoloration at the end of about six weeks, and after two months, the solution became unreliable. The solution stored in the dark for eleven months showed no evidence of deterioration.

On the determination of chlorine in water

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