Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Thorium Nitrate Tetrahydrate 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 Thorium Nitrate Tetrahydrate provides, in addition to common physical constants, a general description including typical appearance, applications, 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, Chloride, Sulfate, Heavy Metals, Iron, Rare Earth Elements, Titanium, and Calcium, Magnesium, Potassium, Sodium.
Th(NO3)4 • 4H2O
Formula Wt 552.11
CAS No. 13470-07-0
GENERAL DESCRIPTION Typical appearance . . . . . . . . . . . . . . . . . . . white solid Applications . . . . . . . . . . . . . . . . . . . . . . . . titrant in fluoride determination Aqueous solubility . . . . . . . . . . . . . . . . . . . . very soluble
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98.0–102.0% Th(NO3)4 · 4H2O
Insoluble matter . . . . . Chloride (Cl) . . . . . . . Sulfate (SO4) . . . . . . . Heavy metals (as Pb) . . Iron (Fe) . . . . . . . . . . Rare earth elements (as Titanium (Ti) . . . . . . . Calcium (Ca) . . . . . . . Magnesium (Mg) . . . . .
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© 2017 American Chemical Society
Maximum Allowable 0.01% 0.002% 0.01% 0.002% 0.002% 0.2% 0.01% 0.01% 0.005%
A
DOI:10.1021/acsreagents.4403 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
Potassium (K) . . . . . . . . . . . . . . . . . . . . . . . 0.005% Sodium (Na) . . . . . . . . . . . . . . . . . . . . . . . . 0.05%
TESTS Assay (By gravimetry). Weigh accurately about 1.0 g, and dissolve in 100 mL of water in a beaker. Add 2 mL of 10% sulfuric acid, heat to boiling, and add 20 mL of a hot 10% oxalic acid solution. Cool, filter, wash with a little water, and ignite the precipitate to constant weight.
Insoluble Matter [Part 2: Gravimetric Methods; Insoluble Matter]. Use 10.0 g dissolved in 100 mL of water. Reserve the filtrate and washings for the preparation of sample solution A.
†
For the Determination of Chloride, Sulfate, Heavy Metals, Iron, Rare Earth Elements, and Titanium
S a m p l e S o l u t i o n A . Transfer the filtrate and washings reserved from the test for insoluble matter to a 200 mL volumetric flask, and dilute with water to 200 mL (1 mL = 0.05 g).
Chloride† [Part 2: Colorimetry and Turbidimetry; Chloride]. Dilute 10 mL (0.5 g sample) of sample solution A with water to 20 mL.
Sulfate† Dilute 10 mL (0.5 g sample) of sample solution A with water to 20 mL. Add 5 mL of 2 N ammonium acetate solution (described below), and transfer the solution to a separatory funnel. Extract with successive 10 mL portions of 0.2 M Nphenylbenzohydroxamic acid (described below) in chloroform until the color of the chloroform layer remains unchanged. Wash the aqueous layer twice with 5 mL portions of chloroform. Transfer the aqueous solution to a beaker, and evaporate on a hot plate (~100 °C) to 2–3 mL. Add 2 mL of nitric acid and 2 mL of hydrochloric acid, cover, and digest on the hot plate (~100 °C) until any reaction ceases. Uncover, wash down the sides of the beaker, and evaporate to dryness. Dissolve the residue in 4 mL of water plus 1 mL of dilute hydrochloric acid (1:19). Filter if necessary through a small filter, wash with two 2 mL portions of water, and dilute with water 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 that has been treated exactly like the sample. Compare 10 min after adding the barium chloride to the sample and standard solutions.
For the Determination of Sulfate
A m m o n i u m A c e t a t e S o l u t i o n , 2 N . Dissolve 15.4 g of ammonium acetate in water, and dilute to 100 mL. N - Ph e n y l b e n z o h y d r o x a m i c A c i d S o l u t i o n , 0 . 2 M . Dissolve 4.26 g of N-phenylbenzohydroxamic acid in chloroform, and dilute to 100 mL with chloroform.
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4403 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
Heavy Metals
†
[Part 2: Colorimetry and Turbidimetry; Heavy Metals (as Lead); Procedure for Heavy Metals, Method 1]. Use 30 mL of sample solution A (1.5 g sample) to prepare the sample solution, and use 10 mL of sample solution A to prepare the control solution.
Iron† [Part 2: Colorimetry and Turbidimetry; Iron; Procedure for Iron, Method 1 (Ammonium Thiocyanate)]. Use 10 mL of sample solution A (0.5 g sample).
Rare Earth Elements† Dilute 5.0 mL (0.25 g sample) of sample solution A to 90 mL with water. Use a pH meter to adjust to pH 4.5 with sodium acetate–acetic acid buffer solution (described below), and dilute with water to 100 mL. To 10 mL in a separatory funnel, add 10 mL of 0.2 M N-phenylbenzohydroxamic acid solution (described above), shake vigorously, allow the layers to separate, and draw off and discard the chloroform layer. Repeat the extraction with 5 mL portions of 0.2 M Nphenylbenzohydroxamic acid solution two more times, drawing off and discarding the chloroform layer each time. Wash the aqueous layer with 5 mL of chloroform, and draw off and discard the chloroform. Add 2 mL of alizarin red S reagent solution, and dilute with water to 50 mL. Adjust the pH of the solution to 4.68 with 0.5 N sodium acetate. Any red color should not exceed that produced by 0.05 mg of lanthanum that has been treated exactly like the 10 mL of the sample.
For the Determination of Rare Earth Elements
S o d i u m A c e t a t e – A c e t i c A c i d B u ff ffeer S o l u t i o n . Dissolve 54.4 g of sodium acetate in water, add 23 mL of acetic acid, and dilute with water to 200 mL.
Titanium† Dilute 10 mL (0.5 g sample) of sample solution A with water to 20 mL and add 0.5 mL of 30% hydrogen peroxide. Any yellow color should not exceed that produced by 0.05 mg of titanium ion (Ti) in an equal volume of solution containing the quantities of reagents used in the test.
Calcium, Magnesium, Potassium, Sodium (By flame AAS, [Part 2: Trace and Ultratrace Elemental Analysis; Atomic Absorption Spectroscopy; Analysis; Procedure for Flame AAS]).
For the Determination of Calcium, Magnesium, Potassium, Sodium
S a m p l e S t o c k S o l u t i o n B . Dissolve 10.0 g of sample in 80 mL of water, add 2 mL of nitric acid (1:1), transfer to a 100 mL volumetric flask, dilute to the mark with water, and mix (1 mL = 0.10 g). S a m p l e S t o c k S o l u t i o n C . Transfer 5.0 mL (0.50 g) of sample stock solution B to a 100 mL volumetric flask, dilute to the mark with water, and mix (1 mL = 0.005 g).
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4403 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
For the Determination of Calcium, Magnesium, Potassium, Sodium
Element
Wavelength (nm)
Sample Wt (g)
Standard Added (mg)
Flame Type*
Background Correction
Ca
422.7
1.0
0.05; 0.10
N/A
No
Mg
285.2
0.20
0.005; 0.01
A/A
Yes
K
766.5
1.0
0.025; 0.05
A/A
No
Na
589.0
0.04
0.01; 0.02
A/A
No
*A/A is air/acetylene; N/A is nitrous oxide/acetylene.
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4403 ACS Reagent Chemicals, Part 4
