Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Sodium Tartrate Dihydrate (2,3-Dihydroxybutanedioic Acid, Disodium Salt, Dihydrate) 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 Sodium Tartrate Dihydrate 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, Loss on Drying, pH of a 5% Solution at 25.0 °C, Insoluble Matter, Chloride, Phosphate, Sulfate, Ammonium, Calcium, Heavy Metals, and Iron.
(CHOHCOONa)2 • 2H2O
Formula Wt 230.08
CAS No. 6106-24-7
Suitable for standardization of Karl Fischer reagent as used for the determination of trace amounts of water (less than 1%).
GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . .
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white solid standardizing Karl Fischer reagent dehydrates at 120 °C 69 g in 100 mL at 43 °C
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99.0–101.0% Na2C4H4O6 · 2H2O Loss on drying . . . . . . . . . . . . . . . . . . . . . . 15.61–15.71% pH of a 5% solution at 25.0 °C . . . . . . . . . . . . 7.0–9.0 Maximum Allowable Insoluble matter . . . . . . . . . . . . . . . . . . . . . 0.005% Chloride (Cl) . . . . . . . . . . . . . . . . . . . . . . . 5 ppm
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4372 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
Phosphate (PO4) . . . Sulfate (SO4) . . . . . Ammonium (NH4) . . Calcium (Ca) . . . . . Heavy metals (as Pb) Iron (Fe) . . . . . . . .
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5 ppm 0.005% 0.003% 0.01% 5 ppm 0.001%
TESTS Assay (Total alkalinity by nonaqueous titration). Weigh accurately about 0.45 g, and dissolve in 100 mL of glacial acetic acid. Titrate with 0.1 N perchloric acid in glacial acetic acid volumetric solution to a green end point using crystal violet indicator solution. One milliliter of 0.1 N perchloric acid corresponds to 0.01151 g of Na2C4H4O6 · 2H2O.
Loss on Drying Weigh accurately 3.0 g into a preconditioned, low-form weighing bottle, and dry at 150 °C to constant weight (minimum 4 h).
pH of a 5% Solution at 25.0 °C [Part 2: Direct Electrometric Methods; pH Potentiometry; pH Range; Procedure for pH of a 5% Solution at 25.0 °C].
Insoluble Matter [Part 2: Gravimetric Methods; Insoluble Matter]. Use 20 g dissolved in 200 mL of water.
Chloride [Part 2: Colorimetry and Turbidimetry; Chloride]. Use 2.0 g.
Phosphate [Part 2: Colorimetry and Turbidimetry; Phosphate; Procedure for Phosphate, Method 1 (Direct Molybdenum Blue)]. Ignite 4.0 g in a platinum dish. Dissolve the residue in 5 mL of water, add 5 mL of nitric acid, and evaporate to dryness. Dissolve the residue in 25 mL of approximately 0.5 N sulfuric acid, and continue as described.
Sulfate Drive off any moisture on a hot plate, and then carefully ignite 1.0 g in an electric muffle furnace until it is nearly free of carbon. Boil the residue with 10 mL of water and 0.5 mL of 30% hydrogen peroxide for 5 min. Add 5 mg of sodium carbonate and 1 mL of hydrochloric acid, and evaporate on a hot plate (~100 °C) to dryness. Dissolve the residue in 4 mL of hot water to which has been added 1 mL of dilute hydrochloric acid (1:19), filter through a small filter, wash with two 2 mL portions of water, and dilute the filtrate to 10 mL. Add 1 mL of 12% barium chloride reagent solution, and mix well. Any turbidity produced should not be greater than that in a standard prepared as described and to which the 12% barium chloride reagent
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4372 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
solution is added at the same time it is added to the sample solution. To 10 mL of water, add 5 mg of sodium carbonate, 1 mL of hydrochloric acid, 0.5 mL of 30% hydrogen peroxide, and 0.05 mg of sulfate ion (SO4), and evaporate on a hot plate (~100 °C) to dryness. Dissolve the residue in 9 mL of water, and add 1 mL of dilute hydrochloric acid (1:19). If necessary, adjust with water to the same volume as the sample solution, add 1 mL of 12% barium chloride reagent solution, and mix well.
Ammonium Dissolve 1.0 g in 60 mL of water. To 20 mL, add 1 mL of 10% sodium hydroxide reagent solution, dilute with water to 50 mL, and add 2 mL of Nessler reagent. Any color should not exceed that produced by 0.01 mg of ammonium ion (NH4) in an equal volume of solution containing the quantities of reagents used in the test.
Calcium (By flame AAS, [Part 2: Trace and Ultratrace Elemental Analysis; Atomic Absorption Spectroscopy; Analysis; Procedure for Flame AAS]).
For the Determination of Calcium
S a m p l e S t o c k S o l u t i o n . Dissolve 10.0 g of sample with water in a 100 mL volumetric flask, add 5 mL of hydrochloric acid, and dilute to the mark with water (1 mL = 0.1 g).
For the Determination of Calcium
Element
Wavelength (nm)
Sample Wt (g)
Standard Added (mg)
Flame Type*
Background Correction
Ca
422.7
0.50
0.05; 0.10
N/A
No
*N/A is nitrous oxide/acetylene.
Heavy Metals [Part 2: Colorimetry and Turbidimetry; Heavy Metals (as Lead); Procedure for Heavy Metals, Method 1]. Dissolve 6.0 g in about 20 mL of water, and dilute with water to 30 mL. Use 25 mL to prepare the sample solution, and use the remaining 5.0 mL to prepare the control solution.
Iron [Part 2: Colorimetry and Turbidimetry; Iron; Procedure for Iron, Method 1 (Ammonium Thiocyanate)]. Use 1.0 g.
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DOI:10.1021/acsreagents.4372 ACS Reagent Chemicals, Part 4
