Ion-exchanger Colorimetry Research Articles

Visual Threshold Detection of Iron(III) at ppb Level Based on Homo-binuclear Complex Formation System Equipped with Ion-exchanger Colorimetry

Visual Threshold Detection of Iron(III) at ppb Level Based on Homo-binuclear Complex Formation System Equipped with Ion-exchanger Colorimetry

Microdetermination of vanadium by ion-exchanger colorimetry

A microdetermination method for vanadium by ion-exchanger colorimetry has been developed. Vanadium is sorbed on the anion-exchanger Dowex 1-X8 as vanadium-benzohydroxamic acid complex in 3 M HCl medium. The resin-phase absorbance at 516 and 800 nm is measured directly. The detection limit is 0.28 μg/liter and the distribution ratio is 340. It is possible to enhance the sensitivity by increasing the sample volume.

Microdetermination of iron in water by ion-exchanger colorimetry with ferrozine

The use of ion-exchanger colorimetry for determination of microamounts of iron in water with 3-(2-pyridyl)-5,6-bis(4-phenylsulphonic acid)-1,2,4-triazine disodium salt as colour reagent is described. The advantages are the high sensitivity, ease of operation, good reproducibility, and simplicity of apparatus. Also, because of concentration by the ion-exchanger resin the detection limit of the method may be as low as the μg ml level.

Determination of nitrite in sea-water by ion-exchanger colorimetry

A microdetermination method (at theμg/l level for nitrite) has been developed, based on ion-exchanger colorimetry. The nitrite is reacted with sulphanilamide andN-(1-naphthyl)ethylenediamine to form an azo dye which is then sorbed on Dowex 50W-X2. The resin phase absorbance at 550 and 800 nm is measured directly. The relative detection limit is 0.27μg/l and the distribution ratio is 2.6×104. The method has been applied to determination of nitrite in 500-ml sea-water samples and compared with a conventional technique.

Coagulated Ion-exchanger Colorimetry for the Determination of Trace Amounts of Sulfide as Methylene Blue

Abstract Sulfide ion was converted to Methylene Blue through the reaction with N,N-dimethyl-p-phenylenediamine in the presence of iron(III) ion. The dye produced was fixed by batch method onto the coagulated mixture of finely divided anion and cation exchange resins. The coagulated material was collected by filtration on a filter paper as a disk of thin layer, which was then soaked in an acetate buffer solution, and subjected to the spectrophotometric analysis. The calibration graph was linear over the range 1.03–10.3 nmol of sulfide. The method was applied to some hot spring waters.

The Coagulated Ion-exchanger Colorimetry of Cobalt(II)–Thiocyanate Complex

Abstract The coagulated ion-exchanger colorimetry was applied to the determination of a trace amount of cobalt(II). Cobalt(II)–thiocyanate complex was fixed by a batch method on the coagulated material composed of fine particles of anion and cation exchangers. The coagulated material was collected on a filter paper and a colored thin layer was prepared. The coloration of the compound was further intensified by dipping the thin layer in a concentrated thiocyanate solution, and the absorbance was determined by a densitometer. The calibration curve showed a good linearity in the range of 1–15 μg of cobalt(II). Iron(III) and copper(II) showed interfering coloration, but these ions were effectively masked by the addition of fluoride and egta, respectively. Zinc(II) gave seriously negative error.

ChemInform Abstract: APPLICATION OF COAGULATED ION‐EXCHANGER COLORIMETRY TO THE DETERMINATION OF TRACE AMOUNTS OF PHOSPHATE IN WATER

Chemischer InformationsdienstVolume 14, Issue 4 Other Subjects ChemInform Abstract: APPLICATION OF COAGULATED ION-EXCHANGER COLORIMETRY TO THE DETERMINATION OF TRACE AMOUNTS OF PHOSPHATE IN WATER K. MATSUHISA, K. MATSUHISASearch for more papers by this authorK. OHZEKI, K. OHZEKISearch for more papers by this authorT. KAMBARA, T. KAMBARASearch for more papers by this author K. MATSUHISA, K. MATSUHISASearch for more papers by this authorK. OHZEKI, K. OHZEKISearch for more papers by this authorT. KAMBARA, T. KAMBARASearch for more papers by this author First published: January 25, 1983 https://doi.org/10.1002/chin.198304377AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume14, Issue4January 25, 1983 RelatedInformation

Application of Coagulated Ion-exchanger Colorimetry to the Determination of Trace Amounts of Phosphate in Water

Abstract The combined use of finely divided anion and cation exchange resins reported previously was partly modified and applied to the determination of trace amounts of phosphate in some environmental water samples, such as rain, snow, lake water and seawater. Both orthophosphate and total phosphate were determined and satisfactory results were obtained.

Ion-exchanger colorimetry—VIII Microdetermination of copper in natural waters

A microdetermination method for copper by ion-exchanger colorimetry has been developed. The porphyrin α,β,γ,gd-tetrakis(4- N-methylpyridyl)porphine was used as the colour reagent. After the complexation at pH 4.5 and 40°, the surplus ligand was converted into the protonated species by addition of sulphuric acid. The complex and the ligand were easily sorbed on the cation-exchange resin, Dowex 50W-X2-H + (100–200 mesh). The resin-phase absorbances of the complex species at 424 nm and of the resin background at 510 nm were used for the measurements. There were no interferences by the foreign ions expected to be present in natural waters, at up to 1000 times the concentration of copper. With a 1 -litre sample the detection limit is 0.072 μg/l. It is possible to determine copper at μg/l. or lower levels in natural waters.

Ion-exchanger colorimetry—VII Microdetermination of iron(II) and iron(III) in natural water

A trace method for iron, based on ion-exchanger colorimetry, has been developed. 1,10-Phenanthroline is used as the colour reagent for iron(II) and citrate as the masking reagent for iron(III). Total iron can be determined after reduction of iron(III) to iron(II) with hydroxylamine. It is possible to determine iron at μg/l.-levels in different oxidation states in natural waters.

An Improved Ion-exchanger Colorimetry for the Determination of a Trace Amount of Phosphate

Abstract A highly sensitive and selective method has been developed for the determination of a trace amount of phosphate. It is based on the concentration of phosphate as the familiar molybdenum blue complex on the coagulated material prepared from finely divided anion and cation exchangers, collection of the mixed resin on a filter paper, and the subsequent measurement of the absorbance of the complex on the resulting thin layer of resin phase. The calibration curve shows a good proportionality in the concentration range of 1 to 6 μg P1−1. The absorbance corresponding to 1 μg P1−1 is 0.095. The method is successfully applied to the determination of phosphate in a tap water and a river water.

Ion-exchanger colorimetry—VI Microdetermination of nickel in natural water

Ion-exchanger colorimetry with 1-(2-pyridylazo)2-naphthol (PAN) has been developed for the determination of nickel at the μg/l. level in natural water. With 1 litre of sample the detection limits are 1.3 × 10 −9 M i.e., 0.077 μg/l. for fresh water and 5.8 × 10 −9 M i.e., 0.34 μg/l. for sea-water. The distribution ratio is 5 × 10 4. Copper and zinc, which form coloured species with PAN in the resin phase, can be completely eluted with a masking solution composed of EDTA and thioglycollic acid (pH 7.8). Cobalt can be determined simultaneously by measurement at 628 nm.

Ion-exchanger colorimetry—IV microdetermination of bismuth in water

Ion-exchanger colorimetry for the microdetermination of bismuth(III) in water samples is described. The yellow bismuth—iodide complexes are specifically sorbed and concentrated on an anion-exchange resin in the sulphate form. The resin-phase absorbances at 492 and 700 nm are measured directly. Bismuth in the ppb—ppm range can be determined without interference, except in presence of a large amount of copper(II), silver(I) and lead(II). The detection limit is 6.4 × 10 −9 M, i.e., 1.3 ppb. The distribution ratio is larger than 10 7. It is, therefore, possible to enhance the sensitivity by increasing the sample volume. The method is useful for the determination of bismuth in natural waters and industrial effluents.

Ion exchanger colorimetry by means of a coagulated material composed of finely divided anion and cation exchange resins

Finely divided ion exchange resin particles can collect ions from solution more rapidly than the beads of conventional size, and by the addition of oppositely charged resin particles, they coagulate each other to form a bulky material which is easily separated by filtration. The coagulated resins are collected on a filter paper as a uniform and thin layer which is directly subjected to the spectrophotometric measurements. A trace amount of chromium(VI) is determined as follows. A 100-ml sample solution containing less than 1.0μg of chromium(VI) and sulfuric acid in the concentration of approximately 0.01 mol dm-3 is taken into a separatory funnel. Then 3.0 ml of anionic resin suspension (7.22×10-3 meq ml-1), 1.0 ml of cationic resin suspension (13.3×10-3 meq ml-1) and finally 1 ml of 0.4% diphenylcarbazide in 50% acetonewater solution are added. The mixture is shaken for 12 min and the resulting coagulated material is collected onto a filter paper (Toyo Roshi No. 5A) set on a holder. The purple colored resins thus obtained form a disk of 17 mm diameter and about 0.3 mm in thickness. To stabilize the coloration, the filter strip is dipped into an acetate buffer solution for 10s and then the absorbance is measured against reagent blank at the absorption maximum of 550 nm and at 700 nm where the complex has no absorption. The net absorbance is obtained as the difference. The working curve deviates slightly from the proportionality, the relative standard deviation being 2.1% (n=6) for 1 μg of chronium(VI) and 3.3% (n=5) for 0.4μg. The sensitivity of the present method is approximately 100-fold higher than the ordinary solution method using 1-cm cell. As a 1-μg portion of chromium(VI) is quantitatively recovered from 400-ml sample solution, the sensitivity is 400-fold higher than the ordinary method.

Ion-exchanger colorimetry—III microdetermination of zinc in water

An ion-exchanger colorimetric method for the determination of zinc(II) with Zincon has been developed. Zinc in a water sample can be determined by sorption onto an anion-exchange resin from 2 M chloride solution followed by transformation into a coloured complex with Zincon. With use of a 1-litre sample the sensitivity is 10 times greater than that for conventional colorimetry. Most metals, except cadmium(II), lead(II) and bismuth(III), do not interfere when present in up to 100 times the concentration of zinc. The zinc: Zincon ratio of the complex in the resin phase was found to be 1 : 1 by the molar ratio method.

Ion-exchanger colorimetry—II microdetermination of chromium in natural waters

Ion-exchanger colorimetry for chromium(VI) with 1,5-diphenylcarbohydrazide has been developed for the determination of chromium at μg/l. concentrations in natural water samples. About 90% of the chromium(VI) in a 1-litre sample solution is concentrated in 200–400 mesh Dowex 50W-X4 resin within half an hour. It is possible to obtain higher sensitivity by employing a larger amount of sample solution. Total chromium can be determined by oxidizing chromium(III) to chromium(VI) with ceric sulphate.

Ion-exchanger colorimetry—I: Micro determination of chromium, iron, copper and cobalt in water

A new sensitive, colorimetric method based on the direct measurement of light-absorption by an ion-exchange resin phase, which has sorbed the sample complex species, has been developed. Determinations ofchromium(VI) with diphenylearbazide, iron(II) with 1,10-phenanthroline, copper with Zincon and cobalt with thiocyanate have more than ten times the sensitivity obtainable with conventional solution colorimetry. The present method can be applied to natural water samples containing very low levels of these metals.