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US-20260126421-A1 - METHOD OF DETERMINING AN AMOUNT OF WATER IN A SAMPLE USING A PHENOL COMPOUND

US20260126421A1US 20260126421 A1US20260126421 A1US 20260126421A1US-20260126421-A1

Abstract

A method for determining an amount of water in a sample includes the steps of providing a reagent including sulfur dioxide and/or a reaction product of sulfur dioxide and an alcohol and/or an amine, and further including a base, and a solvent; providing the sample including water; and titrating the sample with the reagent to determine the amount of water in the sample, wherein the reagent and/or the sample further includes a certain phenol compound.

Inventors

  • Roman Neufeld
  • Thomas Wendt
  • Marco Konopatzki

Assignees

  • HONEYWELL INTERNATIONAL INC.

Dates

Publication Date
20260507
Application Date
20251006

Claims (20)

  1. 1 . A method for determining an amount of water in a sample, said method comprising the steps of: A. providing a reagent comprising sulfur dioxide and/or a reaction product of sulfur dioxide and an alcohol and/or an amine; and further comprising a base; and a solvent; B. providing the sample comprising water; and C. titrating the sample with the reagent to determine the amount of water in the sample; wherein the reagent and/or the sample further comprises a phenol compound chosen from dihydroxybenzene, butylhydroxytoluol, butylhydroxyanisol, 2,2,5,7,8-pentamethyl-6-chromanol, alpha-tocopherol, and combinations thereof.
  2. 2 . The method of claim 1 wherein the reagent and/or the sample further comprises di-tert-butylphenol.
  3. 3 . The method of claim 1 wherein the phenol compound is present in the reagent and/or the sample in an amount of from about 5 to about 5000 parts by weight per one million parts by weight of the reagent and/or the sample, respectively.
  4. 4 . The method of claim 1 wherein the sulfur dioxide and/or the reaction product is present in an amount of from about 0.01 to about 5 mols per liter of the reagent.
  5. 5 . The method of claim 1 wherein the base is imidazole and/or a derivative thereof having the following structure (I): wherein each of R 1 , R 2 , and R 3 is independently a hydrogen atom, a phenyl group, or a hydrocarbyl group, provided that R 1 , R 2 , and R 3 are not all hydrogen atoms.
  6. 6 . The method of claim 5 wherein each of R 1 , R 2 , and R 3 is independently a hydrogen atom, a methyl group, an ethyl group, a propyl group or a butyl group, provided that R 1 , R 2 , and R 3 are not all hydrogen atoms.
  7. 7 . The method of claim 1 wherein the base is present in an amount of from about 0.1 to about 10 mols per liter of the reagent.
  8. 8 . The method of claim 1 wherein the solvent is chosen from xylene, acetonitrile, propionitrile, ethanol, methanol, propanol, butanol, propylene carbonate, 1-methoxypropan-2-ol, monoethylene glycol monoalkyl ether, diethylene glycol monoalkyl ether, and combinations thereof.
  9. 9 . The method of claim 1 wherein the solvent is diethylene glycol monoalkyl ether and the sample further includes an additional solvent that is chosen from xylene, butanol, and combinations thereof.
  10. 10 . The method of claim 1 wherein: the sulfur dioxide and/or the reaction product is present in the reagent in an amount of from about 0.2 to about 0.9 mols per liter of the reagent; the base is present in the reagent in an amount of from about 1 to about 1.8 mols per liter of the reagent; and the solvent is present in the reagent in an amount that makes up the weight balance of the reagent.
  11. 11 . The method of claim 1 wherein the phenol compound is butylhydroxytoluol and is present in the reagent and/or the sample in an amount of from about 100 to about 400 parts by weight per one million parts by weight of the reagent and/or the sample, respectively.
  12. 12 . The method of claim 1 wherein the phenol compound is 2,2,5,7,8-pentamethyl-6-chromanol and is present in the reagent and/or the sample in an amount of from about 50 to about 100 parts by weight per one million parts by weight of the reagent and/or the sample, respectively.
  13. 13 . The method of claim 1 wherein the phenol compound is alpha-tocopherol and is present in the reagent and/or the sample in an amount of from about 50 to about 100 parts by weight per one million parts by weight of the reagent and/or the sample, respectively.
  14. 14 . The method of claim 1 further comprising the step of measuring a stable drift time of the combination of the reagent and the sample and wherein the stable drift time is less than or equal to about 300 s.
  15. 15 . The method of claim 1 that is a volumetric method and that further comprises the step of measuring a stable drift value of the combination of the reagent and the sample and wherein the stable drift value is less than or equal to about 20 μL of water per minute.
  16. 16 . The method of claim 1 that is a coulometric method and that further comprises the step of measuring a stable drift value of the combination of the reagent and the sample and wherein the stable drift value is less than or equal to about 20 μg of water per minute.
  17. 17 . A method for determining an amount of water in a sample, said method comprising the steps of: A. providing a reagent comprising sulfur dioxide and/or a reaction product of sulfur dioxide and an alcohol and/or an amine; and further comprising a base; and a solvent; B. providing the sample comprising water; C. adding a source of iodine to the reagent and/or the sample; and D. titrating the sample with the reagent to determine the amount of water in the sample; wherein the reagent and/or the sample further comprises a phenol compound chosen from dihydroxybenzene, butylhydroxytoluol, butylhydroxyanisol, 2,2,5,7,8-pentamethyl-6-chromanol, alpha-tocopherol, and combinations thereof.
  18. 18 . The method of claim 17 wherein the reagent and/or the sample further comprises di-tert-butylphenol.
  19. 19 . A method for determining an amount of water in a sample, said method comprising the steps of: A. providing a reagent comprising sulfur dioxide and/or a reaction product of sulfur dioxide and an alcohol and/or an amine; and further comprising diethylene glycol monoalkyl ether, and imidazole or a derivative thereof having the following structure (I): wherein each of R 1 , R 2 , and R 3 is independently a hydrogen atom, a phenyl group, or a hydrocarbyl group, provided that R 1 , R 2 , and R 3 are not all hydrogen atoms; B. providing the sample comprising water and xylene; and C. titrating the sample with the reagent to determine the amount of water in the sample; the reagent and/or the sample further comprises a phenol compound chosen from dihydroxybenzene, butylhydroxytoluol, butylhydroxyanisol, 2,2,5,7,8-pentamethyl-6-chromanol, alpha-tocopherol, and combinations thereof; and wherein the phenol compound is present in the reagent and/or the sample and in an amount of from about 5 to about 5000 parts by weight per one million parts by weight of the reagent and/or the sample.
  20. 20 . The method of claim 19 wherein the reagent and/or the sample further comprises di-tert-butylphenol.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims the benefit of U.S. Provisional application No. 63/716,809, filed on Nov. 6, 2024, the entire content of which is hereby incorporated by reference. TECHNICAL FIELD The present disclosure relates to a method of determining an amount of water in a sample. Specifically, the method includes the use of a particular reagent to titrate a sample, wherein the reagent and/or the sample includes a particular phenol compound. BACKGROUND Measuring water or moisture content in various products can provide useful information for various applications and industries, e.g. product quality control, determination of shelf life of various products, etc. Karl Fischer (KF) titration is an effective technique to determine water content by utilizing the following reactions: in an alcoholic or protic solution: and in a non-alcoholic or aprotic solution: wherein B is a base and ROH is an alcohol. Unwanted side reactions like the Bunsen reaction (4) and the hydrolysis reaction of SO3 (5), lead to a deviation from the 1:1 stoichiometry of iodine (I2) and water which can result in too low water findings with an overall stoichiometry between iodine and water of 1:n, where n=1-2. This titration is carried out in two basic forms, namely as a volumetric titration and as a coulometric titration. KF titrations are typically carried out in an alcoholic solution, e.g. methanol. The use of the alcohol solution helps to stabilize the stoichiometry of the KF reactions by moving the equilibrium to reactions (1) and (2). However, unwanted side reactions (4) and (5) can still occur. KF titrations also typically utilize reagents such as pyridine in excess to balance the stoichiometry of iodine and water. However, if an excess of pyridine is used, the determinable water can be altered. For example, a pyridine-SO3 adduct can form, which takes part in a water-consuming side reaction (5) that can falsify the titration results. Apart from the above, other factors can also influence the accuracy of such titrations. For example, using compromised samples may lead to non-ideal titration conditions such as long stable drift time, which can affect the ability to determine water content accurately. Accordingly, there remains an opportunity to develop a KF titration method that provides highly accurate and efficient titrations with a variety of samples. BRIEF SUMMARY This disclosure provides a method for determining an amount of water in a sample. The method includes the steps of providing a reagent including sulfur dioxide and/or a reaction product of sulfur dioxide and an alcohol and/or an amine, and further includes a base, and a solvent; providing the sample including water; and titrating the sample with the reagent to determine the amount of water in the sample, wherein the reagent and/or the sample further includes a phenol compound chosen from dihydroxybenzene, butylhydroxytoluol, butylhydroxyanisol, 2,2,5,7,8-pentamethyl-6-chromanol, alpha-tocopherol, and combinations thereof. An additional method is also provided, wherein the method further includes the step of adding a source of iodine to the reagent and/or the sample. This disclosure further provides a method for determining an amount of water in a sample that includes water and xylene. This method utilizes a reagent that includes sulfur dioxide and/or the reaction product, and further includes diethylene glycol monoalkyl ether, and imidazole or a derivative thereof having the following structure (I): wherein each of R1, R2, and R3 is independently a hydrogen atom, a phenyl group, or a hydrocarbyl group, provided that R1, R2, and R3 are not all hydrogen atoms, and wherein the reagent and/or sample includes the phenol compound in an amount of from about 5 to about 5000 parts by weight per one million parts by weight of the reagent and/or the sample. BRIEF DESCRIPTION OF THE DRAWINGS The present disclosure will hereinafter be described in conjunction with the following drawing figures, wherein FIG. 1 is a collection of line graphs of drift, reported in the y-axis and in a unit of μg/min, as a function of time, reported in the x-axis and in a unit of s, collected from KF titrations of samples that include xylene, water, and optionally butylhydroxytoluol in concentrations of from about 0 to about 400 ppm; FIG. 2 is a collection of line graphs of drift, reported in the y-axis and in a unit of μg/min, as a function of time, reported in the x-axis and in a unit of s, collected from KF titrations of samples that include xylene, water, and optionally 2,2,5,7,8-pentamethyl-6-chromanol in concentrations of from about 0 to about 400 ppm; and FIG. 3 is a collection of line graphs of drift, reported in the y-axis and in a unit of μg/min, as a function of time, reported in the x-axis and in a unit of s, collected from KF titrations of samples that include xylene, water, and optionally alpha-tocopherol in in concentrations of from about 0 to about 400 ppm