Determination of Water by Karl Fischer Titration in Presence of Ferric Salts

Laurene, A. H.

doi:10.1021/ac60069a036

Cited by 5 publications

(3 citation statements)

References 3 publications

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“…Although ferric ion itself can interfere in the determination of water by Fischer titration, its reduction by iodide can be prevented by the presence of the complexing agent 8-hydroxy quinoline. 6 Complexing by the heme of metmyoglobin probably has the same effect. Myoglobin holds water as strongly as lysozyme yet does not show the artifact observed when apparently dry lysozyme is titrated with Fischer reagent.2 This supports our previous argument that the artifact is due to some interaction of lysozyme with the reagent rather than to uptake of water from the glass walls of the vacuum line or during transfer to the titration apparatus.…”

Section: Discussionmentioning

confidence: 98%

Measurement of the strongly held water of myoglobin by drying

Rao

Bryan

1978

Biopolymers

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SynopsisThe Karl Fischer reagent method has been used to study the drying of whale skeletal muscle myoglobin. Drying curves for metmyoglobin were obtained by mechanical pumping (moderate vacuum) and diffusion pumping (high vacuum) a t 20,10,0, -10, and -2OOC. Strongly held water is present in about the same amounts as were previously observed with lysozyme. Nearly all of this strongly held water is still present during the drying of acid denatured metmyoglobin. This suggests that a core structure containing strongly held water is still present a t pH 4.0. Comparison of the drying of metmyoglobin, deoxymyoglobin, and oxymyoglobin indicates that the iron-coordinated water of metmyoglobin is the second most strongly held water of that molecule.

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Section: Discussionmentioning

confidence: 98%

Measurement of the strongly held water of myoglobin by drying

Rao

Bryan

1978

Biopolymers

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“…A spectrophotometric method for the determination of urea utilizes a reaction with p-dimethylaminobenzaldehyde in dilute hydrochloric acid to produce a pigment having an absorption maximum at about 420 mg; hydrazine and semicarbazide interfere, but methods for their removal are given (398). Difficulties in determining water by the Karl Fischer titration when ferric salts are present have been overcome by preliminary complexation of the ferric ion with 8-quinolinol in absolute methanol (222). A reagent slightly different from the Karl Fischer reagent consists of a solution of sulfur dioxide and bromine in chloroform; a visual end point in the titration of samples for water content has been found satisfactory with this reagent; however, alcohols interfere in the titration (24).…”

Section: Sugars and Carbohydratesmentioning

confidence: 99%

Review - Pharmaceuticals and Natural Drugs

Marsh¹,

Hilty²

1955

Anal. Chem.

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“…From the perspective of chemical reactions and industrial applications, water has been often regarded as one of the most common impurities in organic solvents; therefore, to detect and quantify water content is crucial. 1 At present, there are some traditional technologies for the detection of water content, such as Karl Fischer titration, 2 Fourier transform infrared spectroscopy, 3 and electrochemical analysis, 4 etc; however, these methods generally have disadvantages such as high cost, lengthy processes, and low operability. 5 What is more, these general methods only hold for a specific range (usually trace amounts of water) that is difficult to meet in practical situations.…”

Section: ■ Introductionmentioning

confidence: 99%

Two-Stage Three-Dimensional Luminescent Sensing Strategy for Precisely Detecting a Wide Range of Water Content in Tetrahydrofuran

Zhang

et al. 2022

Anal. Chem.

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The development of efficient sensors for detecting water content in organic solvents is highly desirable for various cases in the chemical industry. Relevant sensors based on luminescent materials are promising due to their superior sensitivity and visualization. However, reported luminescent probes are either aggregation-caused quenching-type molecules, which present an emission quenching effect in high water content, or aggregation induced emission-type luminogens, which exhibit weak emission in organic solvents. This factor narrows the targeted water-content sensing range. Herein, we developed a series of indoline-based donor−acceptor−donor luminogens involving twist intramolecular charge transfer and an aggregation-induced emission effect, which exhibited a unique "on−off−on" emission behavior in tetrahydrofuran with the continuous increase of water content from 0% to 99%. Simultaneously, the emission wavelength underwent a process of first red-shift and then blue-shift. Three-dimensional working curves based upon the log value of wavelength and emission intensity ratio versus water content in tetrahydrofuran were established with two-stage characteristics, aiming to visually detect a wide range of water content in organic solvents. Such a sensing method offers extra sensitivity, convenience, and accuracy.

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Determination of Water by Karl Fischer Titration in Presence of Ferric Salts

Cited by 5 publications

References 3 publications

Measurement of the strongly held water of myoglobin by drying

Measurement of the strongly held water of myoglobin by drying

Review - Pharmaceuticals and Natural Drugs

Two-Stage Three-Dimensional Luminescent Sensing Strategy for Precisely Detecting a Wide Range of Water Content in Tetrahydrofuran

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