Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Hydroxylamine Hydrochloride Part 4, Monographs for Reagent Chemicals: General Descriptions, Specifications, and Tests eISBN: 9780841230460 Tom Tyner Chair, ACS Committee on Analytical Reagents James Francis Secretary, ACS Committee on Analytical Reagents
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ABSTRACT This monograph for Hydroxylamine Hydrochloride provides, in addition to common physical constants, a general description including typical appearance, applications, change in state (approximate), and aqueous solubility. The monograph also details the following specifications and corresponding tests for verifying that a substance meets ACS Reagent Grade specifications including: Assay, Clarity of Alcohol Solution, Residue after Ignition, Titrable Free Acid, Ammonium, Sulfur Compounds, Heavy Metals, and Iron.
NH2OH • HCl
Formula Wt 69.49
CAS No. 5470-11-1
GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . .
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colorless, hygroscopic solid determination of mercury melting point, 151 °C; decomposes above this temperature 85 g in 100 mL at 20 °C
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . ≥96.0% NH2OH · HCl Maximum Allowable Clarity of alcohol solution . . . . . . . . . . . . . . . Passes test Residue after ignition. . . . . . . . . . . . . . . . . . 0.05% Titrable free acid . . . . . . . . . . . . . . . . . . . . 25 meq/g Ammonium (NH4) . . . . . . . . . . . . . . . . . . . . Passes test Sulfur compounds (as SO4). . . . . . . . . . . . . . . 0.005% Heavy metals (by ICP–OES) . . . . . . . . . . . . . . 5 ppm Iron (Fe) . . . . . . . . . . . . . . . . . . . . . . . . . . 5 ppm
© 2017 American Chemical Society
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ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4169 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
TESTS Assay
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(By titration of the reductive capacity). Weigh accurately about 1.5 g, previously dried for 24 h over magnesium perchlorate or phosphorus pentoxide, and transfer to a 250 mL volumetric flask. Dissolve in oxygen-free water, dilute to volume with oxygen-free water, and take 25.0 mL of the sample solution. Dissolve 5 g of ferric ammonium sulfate in 30 mL of oxygenfree dilute sulfuric acid (1:50), and add this solution to the sample solution. Protect the solution from oxygen in the air, boil gently for 5 min, and cool. Dilute with 150 mL of oxygen-free water, and titrate with 0.1 N potassium permanganate volumetric solution. One milliliter of 0.1 N potassium permanganate corresponds to 0.003474 g of NH2OH · HCl.
Clarity of Alcohol Solution Dissolve 1.0 g in 25 mL of alcohol, and compare with an equal volume of alcohol. The sample solution should have no more color or turbidity than the alcohol. Retain the solution for the test for ammonium.
Residue after Ignition [Part 2: Gravimetric Methods; Residue after Ignition]. Ignite 2.0 g. Retain the residue for the test for iron.
Titrable Free Acid Dissolve 10.0 g in 50 mL of water, add 0.15 mL of bromphenol blue indicator solution, and titrate with 1 N sodium hydroxide volumetric solution to the blue end point. Not more than 2.5 mL of 1 N sodium hydroxide should be required.
Ammonium To the solution obtained in the test for clarity of alcohol solution, add 1 mL of a solution of chloroplatinic acid (2.6 g in 20 mL). The solution should remain clear for 10 min.
Sulfur Compounds Dissolve 2.0 g in 10 mL of water containing 10 mg of sodium carbonate and add 4 mL of nitric acid. Slowly add 12 mL of 10% hydrogen peroxide solution. Digest in a covered beaker until the reaction ceases, uncover, and evaporate to dryness on a hot plate (~100 °C). Dissolve the residue in 10 mL of water, add 2 mL of dilute hydrochloric acid (1:19), filter if necessary, and dilute with water to 20 mL. To 10 mL, add 1 mL of 12% barium chloride reagent solution. Any turbidity should not exceed that produced by 0.05 mg of sulfate ion (SO4) in an equal volume of solution containing the quantities of reagents used in the test. Compare sample 10 min after adding the barium chloride to the standard.
Heavy Metals ([Part 2: Trace and Ultratrace Elemental Analysis; Inductively Coupled Plasma−Optical Emission Spectroscopy (ICP–OES); Calculation of Heavy Metals (by ICP–OES) Results], by ICP–OES). Use 1.0 g sample.
Iron [Part 2: Colorimetry and Turbidimetry; Iron; Procedure for Iron, Method 1 (Ammonium Thiocyanate)]. To the residue from the test for residue after ignition, add 3 mL of dilute hydrochloric acid (1:1), cover the dish, and digest on a hot plate (~100
© 2017 American Chemical Society
B
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4169 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
Downloaded by CORNELL UNIV on May 27, 2017 | http://pubs.acs.org Publication Date (Web): February 28, 2017 | doi: 10.1021/acsreagents.4169
°C) for 15–20 min. Remove the cover, evaporate to dryness, dissolve the residue in 2 mL of hydrochloric acid, and dilute with water to 50 mL. Use the solution without further acidification.
© 2017 American Chemical Society
C
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4169 ACS Reagent Chemicals, Part 4
