# US 10,309,937 B2 · Method for detecting impurities in ammonium hydroxide > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,309,937 B2 - Document ID: US10309937B2 - Status: Granted - Kind: B2 - Application number: 15/393,731 - Filed: 2016-12-29 - Published: 2017-08-03 - Granted: 2019-06-04 - Earliest claimed: 2016-02-03 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Kihyun Kim; Sooyeon Kim; JungDae Park; Min Soo Suh; Hyang Bong Lee; Kwangshin Lim - Web page: https://patentgrep.com/patent/US10309937B2 ## CPC - G01N 30/06: Preparation - C01C 1/28: Methods of preparing ammonium salts in general - G01N 2030/067: {by reaction, e.g. derivatising the sample} - G01N 2030/8872: {impurities} - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - C01C: AMMONIA; CYANOGEN; COMPOUNDS THEREOF ({metal hydrides, monoborane, diborane or addition complexes thereof C01B6/00}; salts of oxyacids of halogens C01B11/00; peroxides, salts of peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium or tellurium C01B19/00; azides C01B21/08; {compounds other than ammonia or cyanogen, containing nitrogen, non-metals and optionally metals C01B21/082}; metal imides or amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; compounds containing silicon C01B33/00; compounds containing boron C01B35/00) ## Abstract Provided is a method for detecting impurities in ammonium hydroxide. The method for detecting impurities in ammonium hydroxide includes preparing a potassium permanganate solution, preparing ammonium hydroxide, and adding the potassium permanganate solution several times to the ammonium hydroxide so as to detect impurities in the ammonium hydroxide. Potassium permanganate contained in the potassium permanganate solution is added for each time in the range of 0.0001 mol to 0.01 mol per 1 g of ammonia contained in the ammonium hydroxide. ## Claims ### Claim 1 A method for detecting impurities in ammonium hydroxide, the method comprising: preparing ammonium hydroxide having a concentration in a range of 1 wt % to 5 wt %; preparing a liquid chromatography separation system comprising a stationary phase and water; injecting the ammonium hydroxide prepared having a concentration in a range of 1 wt % to 5 wt % into the liquid chromatography separation system; and detecting whether impurities are present in the ammonium hydroxide injected into the liquid chromatography separation system, wherein the stationary phase comprises: silica; and a functional group that is combined with a surface of the silica and is represented by the following chemical formula, wherein, R is n-octadecyl, and a symbol of * means that the functional group is combined with the surface of the silica. ### Claim 2 (depends on 1) The method of claim 1, further comprising adjusting the liquid chromatography separation system to have a pH in a range of 2 to 11.5. ### Claim 3 (depends on 1) The method of claim 1, wherein the detecting whether impurities are present in the ammonium hydroxide comprises measuring absorbance of an eluate flowing out of the liquid chromatography separation system. ### Claim 4 (depends on 3) The method of claim 3, wherein the absorbance measured is ultraviolet light absorbance. ### Claim 5 (depends on 1) The method of claim 1, wherein the liquid chromatography is performed at a pH maintained in a range from about 2 to about 9. ### Claim 6 (depends on 1) The method of claim 1, wherein the stationary phase of the liquid chromatography system has a weaker interaction with the impurities than with ammonium hydroxide. ### Claim 7 (depends on 1) The method of claim 1, wherein the impurities comprise hydrogen peroxide. ### Claim 8 A method for detecting impurities in ammonium hydroxide, the method comprising: injecting ammonium hydroxide having a concentration in a range of 1 wt % to 5 wt % into a liquid chromatography separation system; and detecting whether impurities are present in the ammonium hydroxide injected into the liquid chromatography separation system, wherein the liquid chromatography separation system comprises a stationary phase and water; and wherein the stationary phase comprises silica and a functional group combined with a surface of the silica having the following chemical formula: wherein, R is n-octadecyl, and a symbol of * means that the functional group is combined with the surface of the silica. ### Claim 9 (depends on 8) The method of claim 8, further comprising adjusting the liquid chromatography separation system to have a pH in a range of about 2 to about 11.5. ### Claim 10 (depends on 8) The method of claim 8, wherein the detecting whether impurities are present in the ammonium hydroxide comprises measuring absorbance of an eluate flowing out of the liquid chromatography separation system. ### Claim 11 (depends on 10) The method of claim 10, wherein the absorbance measured is ultraviolet light absorbance. ### Claim 12 (depends on 8) The method of claim 8, wherein the impurities comprise hydrogen peroxide. ### Claim 13 (depends on 1) The method of claim 1, wherein the method can detect impurities present at a concentration of about 5 ppm to about 100 ppm in the ammonium hydroxide. ### Claim 14 (depends on 8) The method of claim 8, wherein the method can detect impurities present at a concentration of about 5 ppm to about 100 ppm in the ammonium hydroxide.