Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Tartaric Acid (2,3-Dihydroxybutanedioic Acid) 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 Tartaric Acid 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, Insoluble Matter, Residue after Ignition, Chloride, Oxalate, Phosphate, Sulfur Compounds, Heavy Metals, and Iron.
HOOC(CHOH)2COOH
Formula Wt 150.09
CAS No. 87-69-4
GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . .
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colorless solid complexing agent melting point, 170 °C 139 g in 100 mL at 20 °C
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . ≥99.0% C4H6O6 Maximum Allowable Insoluble matter . . . . . . . . . . . . . . . . . . . . . 0.005% Residue after ignition. . . . . . . . . . . . . . . . . . 0.02% Chloride (Cl) . . . . . . . . . . . . . . . . . . . . . . . 0.001% Oxalate (C2O4) . . . . . . . . . . . . . . . . . . . . . . Passes test Phosphate (PO4) . . . . . . . . . . . . . . . . . . . . . 0.001%
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4392 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
Sulfur compounds (as SO4). . . . . . . . . . . . . . . 0.002% Heavy metals (as Pb) . . . . . . . . . . . . . . . . . . 5 ppm Iron (Fe) . . . . . . . . . . . . . . . . . . . . . . . . . . 5 ppm
TESTS Assay (By acid–base titrimetry). Weigh accurately about 3.0 g of sample, and transfer to a 250 mL conical flask with about 75 mL of carbon dioxide-free water. Add 0.15 mL of phenolphthalein indicator solution, and titrate with 1 N sodium hydroxide volumetric solution to a faint-pink end point that persists for at least 30 s. One milliliter of 1 N sodium hydroxide corresponds to 0.07504 g of C4H6O6.
Insoluble Matter [Part 2: Gravimetric Methods; Insoluble Matter]. Use 20.0 g dissolved in 200 mL of water.
Residue after Ignition [Part 2: Gravimetric Methods; Residue after Ignition]. Ignite 5.0 g, and moisten the char with 2 mL of sulfuric acid.
Chloride [Part 2: Colorimetry and Turbidimetry; Chloride]. Use 1.0 g.
Oxalate Dissolve 5.0 g in 30 mL of water, and divide into two equal portions. Neutralize one portion with ammonium hydroxide, using litmus paper as the indicator. Add the other portion, and dilute with water to 40 mL. Shake well, cool, and allow to stand at 15 °C for 15 min. Filter, and to 20 mL of the filtrate, add an equal volume of a saturated, filtered solution of calcium sulfate. No turbidity or precipitate should appear in 2 h. (Limit about 0.1%.)
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For the Determination of Phosphate, Sulfur Compounds, and Heavy Metals
S a m p l e S o l u t i o n A . To 10.0 g, add about 10 mg of sodium carbonate, 5 mL of nitric acid, and 5 mL of 30% hydrogen peroxide. Digest in a covered beaker on a hot plate (~100 °C) until reaction ceases. Wash down the cover glass and the sides of the beaker, and evaporate to dryness. Repeat the treatment with nitric acid and peroxide, and again evaporate to dryness. Dissolve the residue in about 30 mL of water, filter if necessary, and dilute with water to 50 mL (1 mL = 0.2 g).
Phosphate† [Part 2: Colorimetry and Turbidimetry; Phosphate; Procedure for Phosphate, Method 1 (Direct Molybdenum Blue)]. Dilute 10 mL of sample solution A (2 g sample) with water to 20 mL, add 25 mL of 0.5 N sulfuric acid, and continue as described.
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4392 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
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Sulfur Compounds
[Part 2: Colorimetry and Turbidimetry; Sulfate; Procedure for Sulfate, Method 1]. Use 4.2 mL of sample solution A (0.84 g sample).
Heavy Metals† [Part 2: Colorimetry and Turbidimetry; Heavy Metals (as Lead); Procedure for Heavy Metals, Method 1]. Dilute 20 mL of sample solution A (4 g sample) with water to 25 mL.
Iron [Part 2: Colorimetry and Turbidimetry; Iron; Procedure for Iron, Method 1 (Ammonium Thiocyanate)]. Use 2.0 g.
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4392 ACS Reagent Chemicals, Part 4
