Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Strontium Nitrate 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 Strontium Nitrate 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, pH of a 5% Solution at 25.0 °C, Insoluble Matter, Loss on Drying, Chloride, Sulfate, Barium, Calcium, Magnesium, Sodium, Heavy Metals, and Iron.
Sr(NO3)2
Formula Wt 211.63
CAS No. 10042-76-9
GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . .
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white solid preparation of strontium standard solutions melting point, 570 °C 66 g in 100 mL at 20 °C
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . ≥99.0% Sr(NO3)2 pH of a 5% solution at 25.0 °C . . . . . . . . . . . . 5.0–7.0
Insoluble matter . Loss on drying . . Chloride (Cl) . . . Sulfate (SO4) . . . Barium (Ba) . . . . Calcium (Ca) . . . Magnesium (Mg) .
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© 2017 American Chemical Society
Maximum Allowable 0.01% 0.1% 0.002% 0.005% 0.05% 0.05% 0.10%
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DOI:10.1021/acsreagents.4381 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
Sodium (Na) . . . . . . . . . . . . . . . . . . . . . . . . 0.10% Heavy metals (by ICP–OES) . . . . . . . . . . . . . . 5 ppm Iron (Fe) . . . . . . . . . . . . . . . . . . . . . . . . . . 5 ppm
TESTS Assay (By complexometric titration of strontium). Weigh accurately about 0.8 g, transfer to a 250 mL beaker, and dissolve in 50 mL of water. Add 5 mL of diethylamine and 25 mg of methylthymol blue indicator mixture. Titrate immediately with 0.1 M EDTA volumetric solution until the blue color just turns to colorless or gray. One milliliter of 0.1 M EDTA corresponds to 0.02116 g of Sr(NO3)2.
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 10.0 g dissolved in 100 mL of water.
Loss on Drying Weigh accurately 2.0 g, and dry at 105 °C for 4 h.
Chloride [Part 2: Colorimetry and Turbidimetry; Chloride]. Use 0.50 g.
Sulfate [Part 2: Colorimetry and Turbidimetry; Sulfate; Procedure for Sulfate, Method 2]. Use 6.0 mL of dilute hydrochloric acid (1:1), and do two evaporations. Allow 30 min for turbidity to form.
Barium, Calcium, Magnesium, and Sodium (By flame AAS, [Part 2: Trace and Ultratrace Elemental Analysis; Atomic Absorption Spectroscopy; Analysis; Procedure for Flame AAS]).
For the Determination of Barium, Calcium, Magnesium and Sodium
S a m p l e S t o c k S o l u t i o n . Dissolve 1.0 g of sample in 50 mL of water in a 100 mL volumetric flask, add 5 mL of nitric acid, and dilute to the mark with water (1 mL = 0.01 g).
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4381 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
For the Determination of Barium, Calcium, Magnesium and Sodium
Element
Wavelength (nm)
Sample Wt (g)
Standard Added (mg)
Flame Type*
Background Correction
Ba
553.6
0.20
0.10; 0.20
N/A
No
Ca
422.7
0.05
0.02; 0.04
N/A
No
Mg
285.2
0.02
0.01; 0.02
A/A
Yes
Na
589.0
0.02
0.01; 0.02
A/A
No
*A/A is air/acetylene; N/A is nitrous oxide/acetylene.
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 2.0 g sample.
Iron Dissolve 2.0 g in 10 mL of dilute hydrochloric acid (1:1), and evaporate to dryness. Repeat the evaporation. Dissolve the residue in 20 mL of water, and add 2 mL of hydrochloric acid. Add 0.10 mL of 0.1 N potassium permanganate volumetric solution, dilute with water to 50 mL, and allow to stand for 5 min. Add 3 mL of ammonium thiocyanate reagent solution. Any red color should not exceed that produced by 0.01 mg of iron ion (Fe) treated exactly as the sample.
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4381 ACS Reagent Chemicals, Part 4
