Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Dimethylglyoxime (2,3-Butanedione Dioxime)
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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
ABSTRACT This monograph for Dimethylglyoxime 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: Melting Point, Suitability for Nickel Determination, Insoluble in Alcohol, and Residue after Ignition.
CH3C:NOHC:NOHCH3
Formula Wt 116.12
CAS No. 95-45-4
GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . .
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white, crystalline solid nickel-specific complexing reagent; determination of palladium melting point, 238–241 °C, with decomposition 0.06 g in 100 mL at 20 °C
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . ≥99.0% (gravimetric) Melting point . . . . . . . . . . . . . . . . . . . . . . . Approximately 240 °C Suitability for nickel determination . . . . . . . . . Passes test Maximum Allowable Insoluble in ethanol . . . . . . . . . . . . . . . . . . . 0.02% Residue after ignition. . . . . . . . . . . . . . . . . . 0.05%
© 2017 American Chemical Society
A
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4122 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
TESTS Melting Point [Part 2: Measurement of Physical Properties; Melting Point].
Suitability for Nickel Determination Dissolve 0.665 g of nickel sulfate hexahydrate in water, and dilute with water to 50 mL. Dilute 20 mL of this solution with water to 100 mL, heat to boiling, and add 0.25 g of the dimethylglyoxime in 25 mL of alcohol. Add dilute ammonium hydroxide (1: 4) dropwise until the solution is alkaline to litmus, cool, and filter. To the filtrate, add 1 mL of the nickel sulfate solution and heat to boiling. A substantial precipitate of red nickel dimethylglyoxime should appear.
Downloaded by CORNELL UNIV on May 28, 2017 | http://pubs.acs.org Publication Date (Web): February 28, 2017 | doi: 10.1021/acsreagents.4122
Insoluble in Alcohol Gently boil 2.0 g with 100 mL of alcohol under a reflux condenser until no more dissolves. Filter through a tared, preconditioned filtering crucible, wash with 50 mL of alcohol in small portions, and dry at 105 °C.
Residue after Ignition [Part 2: Gravimetric Methods; Residue after Ignition]. Ignite 2.0 g.
© 2017 American Chemical Society
B
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4122 ACS Reagent Chemicals, Part 4
