Control, Standard, and Stock Solutions - ACS Reagent Chemicals

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

Control, Standard, and Stock Solutions Part 3, Solutions and Mixtures Used in Tests eISBN: 9780841230460 Tom Tyner Chair, ACS Committee on Analytical Reagents James Francis Secretary, ACS Committee on Analytical Reagents

Downloaded by CORNELL UNIV on May 11, 2017 | http://pubs.acs.org Publication Date (Web): February 28, 2017 | doi: 10.1021/acsreagents.3002

ABSTRACT Many of the tests for impurities require comparison of the color or the turbidity produced under specified conditions by an impurity ion with the color or the turbidity produced under similar conditions by a known amount of the impurity. Three types of solutions are used to determine the amounts of impurities in reagent chemicals: blank, standard, and control.

CONTROL SOLUTIONS Many of the tests for impurities require comparison of the color or the turbidity produced under specified conditions by an impurity ion with the color or the turbidity produced under similar conditions by a known amount of the impurity. Three types of solutions are used to determine the amounts of impurities in reagent chemicals: 1) blank, 2) standard, and 3) control. 1. B l a n k . A solution containing the quantities of solvents and reagents used in the test. 2. S t a n d a r d . A solution containing the quantities of solvents and reagents used in the test plus an added known amount of the impurity to be determined. 3. C o n t r o l . A solution containing the quantities of solvents and reagents used in the test plus an added known amount of the impurity to be determined and a known amount of the reagent chemical being tested. Some of the chemical being tested must be added to the solution because it is known that the chemical interferes with the test. Throughout this book, the expressions “for the control, …” or “for the standard, add X mg of Y ion” mean to add the proper aliquot of one of the standard solutions listed below. These solutions must be prepared at the time of use or checked often enough to make certain that the tests will not be affected by changes in strength of the standard solution during storage. Calibrated volumetric glassware must be used in preparing these solutions.

STANDARD AND STOCK SOLUTIONS Note: In place of standard solutions prepared as described below, commercially available standards may be used after proper dilution. Required quantities may be made per usage or in smaller quantities, as long as the concentration remains the same.

Acetaldehyde (0.1 mg of CH3CHO in 1 mL) Prepare in water by appropriate dilution of an assayed acetaldehyde solution.

© 2017 American Chemical Society

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

DOI:10.1021/acsreagents.3002 ACS Reagent Chemicals, Part 3

ACS Reagent Chemicals

Preparation

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

Acetone (0.1 mg of (CH3)2CO in 1 mL) Dilute 6.4 mL of acetone with water to 1 L. Dilute 2.0 mL of this solution with water to 100 mL. Prepare the solution at the time of use.

Aluminum (0.01 mg of Al in 1 mL) Dissolve 0.100 g of metallic aluminum in 10 mL of dilute hydrochloric acid (1:1), and dilute with water to 100 mL. To 10 mL of this solution, add 25 mL of dilute hydrochloric acid (1:1), and dilute with water to 1 L.

Ammonium (0.01 mg of NH4 in 1 mL)


Dissolve 0.296 g of ammonium chloride in water, and dilute with water to 100 mL. Dilute 10 mL of this solution with water to 1 L.

Antimony (0.1 mg of Sb in 1 mL) Dissolve 0.2743 g of antimony potassium tartrate hemihydrate in 100 mL of water. Add 100 mL of hydrochloric acid, and dilute with water to 1 L.

Arsenic (0.001 mg of As in 1 mL) Dissolve 0.132 g of arsenic trioxide in 10 mL of 10% sodium hydroxide reagent solution, neutralize with 10% sulfuric acid reagent solution, add an excess of 10 mL, and dilute with water to 1 L. To 10 mL of this solution, add 10 mL of 10% sulfuric acid reagent solution, and dilute with water to 1 L.

Barium (0.1 mg of Ba in 1 mL) Dissolve 0.178 g of barium chloride dihydrate in water, and dilute with water to 1 L.

Bismuth (0.01 mg of Bi in 1 mL) Dissolve 0.232 g of bismuth trinitrate pentahydrate in 10 mL of dilute nitric acid (1:9), and dilute with water to 100 mL. Dilute 10 mL of this solution plus 10 mL of nitric acid with water to 1 L.

Bromate (0.1 mg of BrO3 in 1 mL) Dissolve 0.131 g of potassium bromate in water, and dilute with water to 1 L.

Bromide (0.1 mg of Br in 1 mL) Dissolve 1.49 g of potassium bromide in water, and dilute with water to 100 mL. Dilute 10 mL of this solution with water to 1 L.

Cadmium (0.025 mg of Cd in 1 mL) Dissolve 0.10 g of cadmium chloride 2.5-hydrate in water, add 1 mL of hydrochloric acid, and dilute with water to 500 mL. To 25 mL of this solution, add 1 mL of hydrochloric acid, and dilute with water to 100 mL.


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Preparation


Calcium I (0.1 mg of Ca in 1 mL) Dissolve 0.250 g of calcium carbonate in 20 mL of water and 5 mL of 10% hydrochloric acid reagent solution, and dilute with water to 1 L.

Calcium II (0.01 mg of Ca in 1 mL) Dilute 100 mL of calcium I standard solution with water to 1 L.

Carbon (4 mg of C in 1 mL) Dissolve 8.5 g of potassium hydrogen phthalate in water, and dilute to 1 L.


Carbonate (0.3 mg of CO3 , 0.2 mg of CO2, or 0.06 mg of C in 1 mL) Dissolve 0.53 g of sodium carbonate in carbon dioxide-free water, and dilute with carbon dioxide-free water to 1 L. Prepare the solution at the time of use.

Chloride (0.01 mg of Cl in 1 mL) Dissolve 0.165 g of sodium chloride in water, and dilute with water to 100 mL. Dilute 10 mL of this solution with water to 1 L.

Chlorine (0.01 mg of Cl2 in 1 mL) Dilute 1.0 mL of a 2.5% sodium hypochlorite solution with water to 1 L. Correct for any assay not equal to 2.5%. Standardize the sodium hypochlorite solution before use by the following method: Pipette 3 mL into a tared, glass-stoppered flask. Weigh accurately and add 50 mL of water, 2 g of potassium iodide, and 10 mL of acetic acid. Titrate the liberated iodine with 0.1 N sodium thiosulfate volumetric solution, adding 3 mL of starch indicator solution near the end point. Prepare this solution at the time of use. One milliliter of 0.1 N sodium thiosulfate corresponds to 3.723 mg of NaOCl.

Chlorobenzene (0.1 mg of C6H5Cl in 1 mL) Dilute 1.0 mL of chlorobenzene to 100 mL with 2,2,4-trimethylpentane. Dilute 9.0 mL of this solution to 100 mL with 2,2,4trimethylpentane.

Chromate (0.01 mg of CrO4 in 1 mL) Dissolve 1.268 g of potassium dichromate in water, and dilute with water to 1 L. Dilute 1.0 mL of this solution to 100 mL.

Copper Standard for Dithizone Test (0.001 mg of Cu in 1 mL) Dilute 1 mL of the copper stock solution with water to 100 mL. This dilute solution must be prepared immediately before use.

Copper Stock Solution (0.1 mg of Cu in 1 mL) Dissolve 0.393 g of cupric sulfate pentahydrate in water, and dilute with water to 1 L.

Ferric Iron (0.1 mg of Fe3+ in 1 mL) Dissolve 0.863 g of ferric ammonium sulfate dodecahydrate in water, and dilute with water to 1 L.


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Preparation


2+

Ferrous Iron (0.01 mg of Fe

in 1 mL)

Dissolve 0.702 g of ferrous ammonium sulfate hexahydrate in 10 mL of 10% sulfuric acid reagent solution, and dilute with water to 100 mL. Before use, make a further dilution: To 1.0 mL of the first solution, dilute with water to 100 mL containing 0.10 mL of sulfuric acid.

Fluoride Standard Solution (0.005 mg in 1 mL) Transfer 5.0 mL of the fluoride stock solution to a 1 L plastic volumetric flask, dilute with water to the mark, and store in a plastic bottle. Prepare the solution at the time of use.

Fluoride Stock Solution (1 mg of F in 1 mL)


Dissolve 2.21 g of sodium fluoride, previously dried at 110 °C for 2 h, and dissolve with 200 mL of water in a 400 mL plastic beaker. Transfer to a 1 L volumetric flask, dilute with water to the mark, and store the solution in a plastic bottle.

Formaldehyde I (0.1 mg of HCHO in 1 mL) Dilute 2.7 g (2.7 mL) of 37% formaldehyde solution to 1 L with water (prepare freshly as needed). Dilute 10 mL of this solution to 100 mL.

Formaldehyde II (0.01 mg of HCHO in 1 mL) Dilute 10 mL of formaldehyde I standard solution with water to 100 mL. Prepare the solution at the time of use.

Hydrogen Peroxide (0.1 mg of H2O2 in 1 mL) Dilute 3.0 mL of 30% hydrogen peroxide with water to 100 mL. Dilute 1.0 mL of this solution with water to 100 mL. Prepare the solution at the time of use.

Iodate I (0.10 mg of IO3 in 1 mL) Dissolve 0.123 g of potassium iodate in water, and dilute to 1 L.

Iodate II (0.01 mg of IO3 in 1 mL) Dilute 10 mL of iodate I standard solution to 100 mL.

Iodide (0.01 mg of I in 1 mL) Dissolve 0.131 g of potassium iodide in water, and dilute with water to 100 mL. Dilute 10 mL of this solution with water to 1 L.

Iron (0.01 mg of Fe in 1 mL) Dissolve 0.702 g of ferrous ammonium sulfate hexahydrate in 10 mL of 10% sulfuric acid reagent solution, and dilute with water to 100 mL. To 10 mL of this solution, add 10 mL of 10% sulfuric acid reagent solution, and dilute with water to 1 L.

Lead Standard for Dithizone Test (0.001 mg of Pb in 1 mL) Dilute 1 mL of lead stock solution to 100 mL with dilute nitric acid (1: 99). This solution must be prepared immediately before use.


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Preparation


Lead Standard for Heavy Metals Test (0.01 mg of Pb in 1 mL) Dilute 10 mL of lead stock solution to 100 mL with water. This dilute solution must be prepared at the time of use.

Lead Stock Solution (0.1 mg of Pb in 1 mL) Dissolve 0.160 g of lead nitrate in 100 mL of dilute nitric acid (1:99), and dilute with water to 1 L. The solution should be prepared and stored in containers free from lead. Its strength should be checked every few months to determine whether the lead content has changed by reaction with the container.

Magnesium I (0.01 mg of Mg in 1 mL)


Dissolve 1.014 g of clear crystals of magnesium sulfate heptahydrate in water, and dilute with water to 100 mL. Dilute 10 mL of this solution with water to 1 L.

Magnesium II (0.002 mg of Mg in 1 mL) Dilute 100 mL of magnesium I standard solution with water to 500 mL. Prepare the solution at the time of use.

Manganese (0.01 mg of Mn in 1 mL) Dissolve 3.08 g of manganese sulfate monohydrate in water, and dilute with water to 1 L. Dilute 10 mL of this solution with water to 1 L.

Mercury (0.05 mg of Hg in 1 mL) Dissolve 1.35 g of mercuric chloride in water, add 8 mL of hydrochloric acid, and dilute with water to 1 L. To 50 mL of this solution, add 8 mL of hydrochloric acid, and dilute with water to 1 L.

Methanol (0.1 mg of CH3OH in 1 mL) Dilute 5.1 mL of methanol with water to 200 mL. Dilute 5.0 mL of this solution with water to 1 L. Prepare the solution at the time of use.

Molybdenum (0.01 mg of Mo in 1 mL) Dissolve 0.150 g of molybdenum trioxide in 10 mL of dilute ammonium hydroxide (1:9), and dilute with water to 100 mL. Dilute 10 mL of this solution with water to 1 L.

Nickel (0.01 mg of Ni in 1 mL) Dissolve 0.448 g of nickel sulfate hexahydrate in water, and dilute with water to 100 mL. Dilute 10 mL of this solution with water to 1 L.

Nitrate (0.01 mg of NO3 in 1 mL) Dissolve 0.163 g of potassium nitrate in water, and dilute with water to 100 mL. Dilute 10 mL of this solution with water to 1 L.


E




Preparation


Nitrilotriacetic Acid (10 mg of (HOCOCH2)3N in 1 mL) Transfer 1 g of nitrilotriacetic acid to a 100 mL volumetric flask. Dissolve in 10 mL of 10% potassium hydroxide solution, and dilute to the mark with water.

Nitrite I (0.01 mg of NO2 in 1 mL) Dissolve 0.150 g of sodium nitrite in water, and dilute with water to 100 mL. Dilute 1.0 mL of this solution with water to 100 mL. This solution should be freshly prepared.

Nitrite II (0.001 mg of NO2 in 1 mL) Dilute 0.1 mL of nitrite I standard solution with water to 100 mL. This solution must be prepared at the time of use.


Nitrogen (0.01 mg of N in 1 mL) Dissolve 0.382 g of ammonium chloride in water, and dilute with water to 100 mL. Dilute 10 mL of this solution with water to 1 L.

Phosphate (0.01 mg of PO4 in 1 mL) Dissolve 0.143 g of monobasic potassium phosphate in water, and dilute with water to 100 mL. Dilute 10 mL of this solution with water to 1 L.

Platinum–Cobalt Standard (APHA No. 500) See [Part 2: Measurement of Physical Properties; Color (APHA)].

Potassium (0.01 mg of K in 1 mL) Dissolve 0.191 g of potassium chloride in water, and dilute with water to 1 L. Dilute 100 mL of this solution with water to 1 L.

Potassium Bromide (0.003 mg of KBr in 1 mL) Dissolve 3 mg of potassium bromide in 1 L of water. Prepare fresh before use.

Selenium (1 µg of Se in 1 mL) Transfer 0.10 mL of selenium standard (1000 µg/g Se, commercially available standard) to a 100 mL volumetric flask, and dilute to the mark with water. Prepare fresh before use.

Silica (0.01 mg of SiO2 in 1 mL) Dissolve 0.473 g of sodium silicate in 100 mL of water in a platinum or polyethylene dish. Dilute 10 mL of this solution (polyethylene graduate) with water to 1 L in a polyethylene bottle.

Silver (0.1 mg of Ag in 1 mL) Dissolve 0.157 g of silver nitrate in water, and dilute with water to 1 L. Store in an opaque plastic bottle.


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Preparation


Sodium (0.01 mg of Na in 1 mL) Dissolve 0.254 g of sodium chloride in water, and dilute with water to 1 L. Dilute 100 mL of this solution with water to 1 L.

Strontium I (0.1 mg of Sr in 1 mL) Dilute 10 mL of strontium stock solution with water to 100 mL.

Strontium II (0.01 mg of Sr in 1 mL) Dilute 10 mL of strontium stock solution with water to 1 L.

Strontium Stock Solution (1 mg of Sr in 1 mL) Downloaded by CORNELL UNIV on May 11, 2017 | http://pubs.acs.org Publication Date (Web): February 28, 2017 | doi: 10.1021/acsreagents.3002

Dissolve 0.242 g of strontium nitrate in water, and dilute with water to 100 mL.

Sulfate (0.01 mg of SO4 in 1 mL) Dissolve 0.148 g of anhydrous sodium sulfate in water, and dilute with water to 100 mL. Dilute 10 mL of this solution with water to 1 L.

Sulfide (0.01 mg of S in 1 mL) (Note: If liquid is observable on crystals, blot the crystals with filter paper and then weigh.) Dissolve 0.75 g of sodium sulfide nonahydrate in water, and dilute with water to 100 mL. Dilute 10 mL of this solution with water to 1 L. This solution must be prepared immediately before use.

Tin (0.05 mg of Sn in 1 mL) Dissolve 0.100 g of metallic tin (Sn) in 10 mL of dilute hydrochloric acid (1:1), and dilute with water to 100 mL. Dilute 5 mL of this solution with dilute hydrochloric acid (1:9) to 100 mL. This solution must be prepared immediately before use.

Titanium I (0.1 mg of Ti in 1 mL) Cool separately in small beakers surrounded by crushed ice 3.96 g (2.3 mL) of titanium tetrachloride and 25 mL of 20% hydrochloric acid. Add dropwise the titanium tetrachloride to the chilled hydrochloric acid. Allow the mixture to stand at ice temperature until all the solid dissolves. Transfer to a 1 L volumetric flask, and dilute to the mark with water. Dilute 10 mL of this solution to 100 mL in a volumetric flask.

Titanium II (0.01 mg of Ti in 1 mL) Dilute 10 mL of titanium I standard solution to 100 mL in a volumetric flask. Prepare fresh at time of use.

Zinc Standard for Dithizone Tests (0.001 mg of Zn in 1 mL) Dilute 1 mL of zinc stock solution with water to 100 mL. This dilute solution must be prepared immediately before use.

Zinc Stock Solution (0.1 mg of Zn in 1 mL) Dissolve 0.124 g of zinc oxide in 10 mL of dilute sulfuric acid (1:9), and dilute with water to 1 L.


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Control, Standard, and Stock Solutions - ACS Reagent Chemicals

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