Ferric Chloride Hexahydrate - ACS Reagent Chemicals (ACS

Monograph pubs.acs.org/doi/book/10.1021/acsreagents

Ferric Chloride Hexahydrate (Iron(III) Chloride Hexahydrate)

Downloaded by CORNELL UNIV on June 12, 2017 | http://pubs.acs.org Publication Date (Web): February 28, 2017 | doi: 10.1021/acsreagents.4143

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 Ferric Chloride Hexahydrate 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, Nitrate, Sulfate, Phosphorus Compounds, Calcium, Copper, Magnesium, Potassium, Sodium, Zinc, and Ferrous Iron.

FeCl3 · 6H2O

Formula Wt 270.29

CAS No. 10025-77-1

GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . .

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brownish-yellow deliquescent solid clinical reagent (amino acids in urine) melting point, 37 °C 92 g in 100 mL

SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97.0–102.0% FeCl3 · 6H2O

Insoluble matter . . . . . . . . . . Nitrate (NO3) . . . . . . . . . . . . Sulfate (SO4) . . . . . . . . . . . . Phosphorus compounds (as PO4) Calcium (Ca) . . . . . . . . . . . . Copper (Cu) . . . . . . . . . . . . . Magnesium (Mg) . . . . . . . . . .

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© 2017 American Chemical Society

Maximum Allowable 0.01% 0.01% 0.01% 0.01% 0.01% 0.003% 0.005%

A

ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.

DOI:10.1021/acsreagents.4143 ACS Reagent Chemicals, Part 4

ACS Reagent Chemicals

Monograph

pubs.acs.org/doi/book/10.1021/acsreagents

Potassium (K) . . . . Sodium (Na) . . . . . Zinc (Zn) . . . . . . . Ferrous iron (Fe++).

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0.005% 0.05% 0.003% 0.002%

TESTS


Assay (By iodometric titration of oxidative capacity of FeIII). Weigh accurately about 1.0 g, and transfer to an iodine flask with 50 mL of water. Add 3 mL of hydrochloric acid and 3.0 g of potassium iodide. Stopper, swirl, and allow to stand in the dark for 30 min. Dilute with 100 mL of water, and titrate the liberated iodine with 0.1 N sodium thiosulfate, adding 3 mL of starch indicator solution near the end of the titration. Correct for a blank. One milliliter of 0.1 N sodium thiosulfate corresponds to 0.02703 g of FeCl3 · 6H2O.

Insoluble Matter [Part 2: Gravimetric Methods; Insoluble Matter]. Use 10.0 g dissolved in 50 mL of dilute hydrochloric acid (1:49).

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For the Determination of Nitrate and Sulfate

S a m p l e S o l u t i o n S . In a 150 mL beaker, dissolve 10.0 g in 75 mL of water, heat to boiling, and pour slowly with constant stirring into 200 mL of dilute ammonium hydroxide (1:3). Filter through a folded filter while still hot, wash with hot water until the volume of the filtrate plus washings measures 300 mL, and thoroughly mix the solution (1 mL = 0.033 g).

Nitrate† [Part 2: Colorimetry and Turbidimetry; Nitrate; Procedure for Nitrate, Method 1 (Brucine Sulfate)].

For the Determination of Nitrate

S a m p l e S o l u t i o n A . Add 42 mL of brucine sulfate reagent solution and 2 mL of water to 6 mL of sample solution S (0.2 g sample). C o n t r o l S o l u t i o n B . Add 42 mL of brucine sulfate reagent solution and 2 mL of nitrate ion (NO3) standard solution to 6 mL of sample solution S. B l a n k S o l u t i o n C . Add 42 mL of brucine sulfate reagent solution to 8 mL of water.

Continue with the procedure as described.


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Monograph


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Sulfate

[Part 2: Colorimetry and Turbidimetry; Sulfate; Procedure for Sulfate, Method 1]. Evaporate 15 mL of sample solution S to 10 mL. Allow 30 min for turbidity to form.


Phosphorus Compounds In a 250 mL beaker, dissolve 5.0 g in 40 mL of dilute nitric acid (1:1), and evaporate on a hot plate (~100 °C) to a syrupy residue. Dissolve the residue in about 80 mL of water, dilute with water to 100 mL, and dilute 20 mL of this solution with water to 100 mL. For the test solution, dilute 10 mL (0.1 g sample) with water to 70 mL. Prepare a standard containing 0.01 mg of phosphate ion (PO4) in 70 mL of water. To each solution, add 5 mL of 10% ammonium molybdate reagent solution, and adjust the pH to 1.8 (using a pH meter) by adding dilute hydrochloric acid (1:1) or dilute ammonium hydroxide (1:1). Cautiously heat the solutions to boiling but do not boil, and cool to room temperature. If a precipitate forms, it will dissolve when the solution is acidified in the next step. To each solution, add 10 mL of hydrochloric acid, and dilute each with water to 100 mL. Transfer the solutions to separatory funnels, add 35 mL of diethyl ether to each, shake vigorously, and allow to separate. Draw off and discard the aqueous phases. Wash the ether phases twice with 10 mL portions of dilute hydrochloric acid (1:9), discarding the washings each time. To the washed ether phases, add 10 mL of dilute hydrochloric acid (1:9) to which has just been added 0.2 mL of a freshly prepared 2% stannous chloride reagent solution (in hydrochloric acid). Shake the solutions, and allow the phases to separate. Any blue color in the ether phase from the solution of the sample should not exceed that in the ether phase from the standard.

Calcium, Copper, Magnesium, Potassium, Sodium, and Zinc (By flame AAS, [Part 2: Trace and Ultratrace Elemental Analysis; Atomic Absorption Spectroscopy; Analysis; Procedure for Flame AAS]).

For the Determination of Calcium, Copper, Magnesium, Potassium, Sodium, and Zinc

S a m p l e S t o c k S o l u t i o n A . Dissolve 10.0 g of sample with water in a 100 mL volumetric flask, and dilute to the mark with water (1 mL = 0.10 g). S a m p l e S t o c k S o l u t i o n B . Transfer 5.0 mL (0.50 g) of sample stock solution A to a 100 mL volumetric flask, dilute to the mark with water, and mix (1 mL = 0.005 g).

For the Determination of Calcium, Copper, Magnesium, Potassium, Sodium, and Zinc

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

Cu

324.7

1.0

0.03; 0.06

A/A

Yes

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

Zn

213.9

0.20

0.005; 0.01

A/A

Yes

*A/A is air/acetylene; N/A is nitrous oxide/acetylene.

Ferrous Iron Dissolve 10 g in 80 mL of 1:19 hydrochloric acid, then dilute to 100 mL with 1:19 hydrochloric acid. To 20 mL of sample, add 2.0 mL of water. To 10 mL of sample, add 2.0 mL of 0.01 mg/mL ferrous iron standard and 10 mL of water. Add 0.1 mL of


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Monograph



freshly prepared 5% potassium ferricyanide solution to sample and standard. Stopper and mix. Any blue-green color in the sample should not exceed that in the standard. (Limit about 0.002%.)


D



Ferric Chloride Hexahydrate - ACS Reagent Chemicals (ACS

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