by Cupric Sulphate, 0.02 M:
Dissolve 5.0 g of cupric sulphate in water and dilute to 1000 ml with water. Standardize the solution in the following manner.
To 20.0 ml add 2 g of sodium acetate and titrate with 0.02 M disodium edetate, using 0.1 ml of pyridylazonaphthol solution as indicator, until the colour changes from violet-blue to bright green, adding the titrant slowly towards the end-point. 1 ml of 0.02 M disodium edetate is equivalent to 0.004994 g of CuSO4,5H2O.
Dioctyl Sodium Sulphosuccinate, 0.0005 M:
Dissolve 0.225 g of dicotyl sodium sulphosuccinate in warm water, cool and dilute to 1000 ml with water. Standardize the solution in the following manner.
To 25.0 ml add 25.0 ml of a solution containing 20 per cent w/v of anhydrous sodium sulphate and 2 per cent w/v sodium carbonate, 50 ml of chloroform and 1.5 ml of bromophenol blue solution and mix. Titrate with 0.01 M tetrabutylammonium iodide until about 1 ml remains to be added for the end-point. Stopper the flask, shake vigorously for 2 minutes and continue the titration, in increments of 0.5 ml, shaking vigorusly and allowing the flask to stand for about 10 seconds after each addition. Continue the titration until a blue colour just appears in the chloroform layer. 1 ml of 0.01 M tetrabutylammonium iodide is equivalent to 0.004446 g of C20H37NaO7S.
Disodium Edetate, 0.1 M:
Dissolve 37.2 g of disodium edetate in sufficient water to produce 1000 ml. Standardize the solution in the following manner.
Weigh accurately about 0.8 g of granulated zinc, dissolve by gentle warming in 12 ml of dilute hydrochloric acid and 0.1 ml of bromine water. Boil to remove excess bromine, cool and add sufficient water to produce 200.0 ml. Pipette 20.0 ml of the resulting solution into a flask and nearly neutralise with 2 M sodium hydroxide. Dilute to about 150 ml with water, add sufficient ammonia buffer pH 10.0 to dissolve the precipitate and add 5 ml in excess. Add 50 mg of mordant black II mixture and titrate with the disodium edetate solution until the solution turns green. 1 ml of 0.1 M disodium edetate is equivalent to 0.000654 g of
Zn.
Ferric Ammonium Sulphate, 0.1 M:
Ammonium Iron(III) Sulphate, 0.1M: Dissolve 50 g of ferric ammonium sulphate in a mixture of 300 ml of water and 6 ml of sulphuric acid and dilute with sufficient freshly boiled and cooled water to produce 1000 ml. Standardize the solution in the following manner.
To 25.0 ml add 3 ml of hydrochloric acid and 2 g of potassium iodide, allow to stand for 10 minutes and titrate the liberated iodine with 0.1 M sodium thiosulphate using starch solution, added towards the end of the titration, as indicator.
1 ml of 0.1 M sodium thiosulphate is equivalent to 0.004822 g of FeNH4(SO4)2,12H2O.
Ferrous Ammonium Sulphate, 0.1 M;
Ammonium Iron(II) Sulphate, 0.1M; Dissolve 40 g of ferrous ammonium sulphate in a previously cooled mixture of 40 ml of sulphhuric acid and 200 ml of water, dilute with sufficient freshly boiled and cooled water to produce 1000 ml. Standardize the solution in the following manner.
Measure accurately 25.0 ml of the solution into a flask, add 2 drops of 1,10-phenanthroline solution and titrate with 0.1 M ceric ammonium sulphate until the red colour is changed to pale blue. 1 ml of 0.1 M ceric ammonium sulphate is equivalent to 0.03921g of Fe(NH4)2(SO4)2, 6H2O.
Hydrochloric Acid, 1 M:
Dilute 85 ml of hydrochloric acid with water to produce 1000 ml. Standardize the solution in the following manner.
Weigh accurately about 1.5 g of anhydrous sodium carbonate, previously heated at about 270º for 1 hour. Dissolve it in 100 ml of water and add 0.1 ml of methyl red solution. Add the acid slowly from a burette, with constant stirring, until the solution becomes faintly pink. Heat the solution to boiling, cool and continue the titration. Heat again to boiling and titrate further as necessary until the faint pink colour is no longer affected by continued boiling. 1 ml of 1 M hydrochloric acid is equivalent to 0.05299 g of
Na2CO3.
Hydrochloric Acid, 0.5 M Methanolic:
Take 40 ml of water in a 1000-ml volumetric flask and slowly add 43 ml of hydrochloric acid. Cool and add methanol to volume. Standardize the solution in the following manner.
Weigh accurately about 800 mg of anhydrous sodium carbonate, previously heated at about 270º for 1 hour, and proceed as directed under 1 M hydrochloric acid.
Iodine, 0.05 M:
Dissolve about 14 g of iodine in a solution of 36 g of potassium iodide in 100 ml of water, add three drops of hydrochloric acid and dilute with water to 1000 ml. Standardize the solution in the following manner.
Weigh accurately about 0.15 g of arsenic trioxide, previously dried at 105º for 1 hour, and dissolve in 20 ml of 1 M sodium hydroxide by warming, if necessary. Dilute with 40 ml of water, add 0.1 ml of methyl orange solution and add dropwise dilute hydrochloric acid until the yellow colour is changed to pink. Add 2 g of sodium carbonate, dilute with 50 ml of water and add 3 ml of starch solution. Titrate with the iodine solution until a permanent blue colour is produced. 1 ml of 0.05 M iodine is equivalent to 0.004946 g of As2O3. Store in amber-coloured, glass stoppered bottles.
Lead Nitrate, 0.1 M:
Dissolve 33.12 g of lead nitrate in sufficient water to produce 1000 ml. Standardize the solution in the following manner.
Pipette 50.0 ml of the solution into a flask, add 50 mg of xylenol orange mixture and sufficient hexamine to produce a violetpink colour and titrate with 0.1 M disodium edetate to a lemon yellow end point. 1 ml of 0.1 M disodium edetate is equivalent to 0.03312 g of Pb(NO3)2.
Lithium Methoxide, 0.1 M:
Dissolve in small portions 0.7 g of freshly cut lithium in 150 ml of anhydrous methanol, cooling the flask during the addition of the metal. When reaction is complete add sufficient toluene to produce 1000 ml. If cloudiness or precipitation occurs, add sufficient anhydrous methanol to clarify the solution. Standardize the solution immediately before use in the following manner.
Weigh accurately about 0.25 g of benzoic acid, dissolve in 25 ml of dimethylformamide. Titrate with lithium methoxide solution, using quinaldine red solution as the indicator and protecting the solution from atmospheric carbon dioxide throughout the titration. Perform a blank determination and make any necessary correction. 1 ml of 0.1 M lithium methoxide is equivalent to 0.01221 g of C7H6O2. Store the solution in a manner suitably protected from carbon dioxide and moisture.
Magnesium Sulphate, 0.05 M:
Dissolve 12.5 g of magnesium sulphate in sufficient water to produce 1000 ml. Standardize the solution in the following manner.
Pipette 30.0ml of solution into a flask, add 20 ml of water, 10 ml of strong ammonia-ammonium chloride solution and 50 mg of mordant black 11 mixture . Titrate with 0.1 M disodium edetate until the colour changes from violet to full blue. 1 ml of 0.1 M disodium edetate is equivalent to 0.02465 g of MgSO4,7H2O.
Mercuric Nitrate, 0.02 M:
Dissolve 6.85 g of mercuric nitrate in 20 ml of 1 M nitric acid and add sufficient water to produce 1000 ml. Standardize the solution in the following manner.
Dissolve 15 mg of sodium chloride in 50 ml of water and titrate with the mercuric nitrate solution determining the endpoint potentiometrically, using a platinum or mercury indicator electrode and a mercury-mercurous sulphate reference electrode. 1 ml of 0.02 M mercuric nitrate is equivalent to 0.002338 g of NaCl.
Nitric Acid, 1 M:
Dilute 63 ml of nitric acid with sufficient water to produce 1000 ml. Standardize the solution in the following manner.
Dissolve 2 g of anhydrous sodium carbonate in 50 ml of water and titrate with the nitric acid solution using methyl orange solution as indicator until the solution becomes reddish yellow. Boil for 2 minutes, cool and continue the titration until the reddish yellow colour is restored. 1 ml of 1 M nitric acid is equivalent to 0.053 g of Na2CO3.
Perchloric Acid, 0.1 M:
Mix 8.5 ml of perchloric acid with 500 ml of anhydrous glacial acetic acid and 25 ml of acetic anhydride, cool and add anhydrous glacial acetic acid to produce 1000 ml. Allow the prepared solution to stand for 1 day for the excess acetic anhydride to be combined and carry out the determination of water. If the water content exceeds 0.05 percent, add more acetic anhydride. If the solution contains no titratable water, add sufficient water to obtain a content of water between 0.02 per cent and 0.05 per cent. Allow the solution to stand for 1 day and again titrate the water content. The solution so obtained should contain between 0.02 per cent and 0.05 per cent of water. Standardize the solution in the following manner.
Weigh accurately about 0.35 g of potassium hydrogen phthalate, previously powdered lightly and dried at 120º for 2 hours and dissolve it in 50 ml of anhydrous glacial acetic acid. Add 0.1 ml of crystal violet solution and titrate with the perchloric acid solution until the violet colour changes to emerald-green. Peform a blank determination and make any necessary correction. 1 ml of 0.1 M perchloric acid is equivalent to 0.02042 g of C8H5KO4.
Other strengths of perchloric acid should be prepared by diluting 0.1 M perchloric acid appropriately with anhydrous glacial acetic acid. In the tests and assays of the Pharmacopoeia, this solution is specified as “0.1 M perchloric acid”. Thus the solution in anhydrous glacial acetic acid is to be used unless the words “in dioxan” are stated.
Potassium Dichromate, 0.0167 M:
Weigh 4.9 g of potassium dichromate, previously powdered and dried in a desiccator for 4 hours, and dissolve in sufficient water to produce 1000 ml. Standardize the solution in the following manner.
To 20.0 ml of the solution add 1 g of potassium iodide and 7 ml of 2 M hydrochloric acid. Add 250 ml of water and titrate with 0.1 M sodium thiosulphate, using 3 ml of starch solution,
added towards the end point of the titration, as indicator until the colour changes from blue to light green. 1 ml of 0.1 M sodium thiosulphate is equivalent to 0.0049 g of K2Cr2O7.
Potassium Hydrogen Phthalate, 0.05 M:
Dissolve 10.21 g of potassium hydrogen phthalate in about 800 ml of anhydrous glacial acetic acid, heat on a water-bath until completely dissolved, protected from humidity, cool to 20° and add sufficient anhydrous glacial acetic acid to produce 1000 ml.
Potassium Hydroxide, 0.1 M:
Dissolve about 6 g of potassium hydroxide in sufficient carbon dioxide free water to produce 1000 ml. Standardize the solution in the following manner.
Titrate 20.0 ml of the solution with 0.1 M hydrochloric acid using 0.5 ml of phenolphthalein solution as indicator. 1 ml of 0.1 M hydrochloric acid is equivalent to 0.005611 g of KOH.
Potassium Hydroxide, 0.1 M Ethanolic:
Dissolve about 6 g of potassium hydroxide in 5 ml of water and add sufficient aldehyde-free ethanol (95 per cent) to produce 1000 ml. Allow the solution to stand in a tightly-stoppered bottle for 24 hours. Then quickly decant the clear supernatant liquid
into a suitable, tightly-closed container and standardize the solution in the following manner.
Pipette 20.0 ml of 0.1 M hydrochloric acid into a flask, dilute with 50 ml of water, add 0.1 ml of phenolphthalein solution and titrate with the ethanolic potassium hydroxide solution until a permanent pale pink colour is produced. 1 ml of 0.1 M hydrochloric acid is equivalent to 0.00561 g of KOH. Store protected from light and moisture.
Potassium Hydroxide in ethanol (60 per cent), 0.5 M:
Dissolve 30 g of potassium hydroxide in sufficient ethanol (60 per cent) to produce 1000 ml. Standardize the solution in the following manner.
Pipette 20.0 ml of standardize 0.5 M hydrochloric acid into a flask, add 0.1 ml of phenolphthalein solution and titrate with the ethanolic potassium hydroxide solution until permanent pale-pink colour is produced. 1 ml of 0.5 M hydrochloric acid is equivalent to 0.02806 g of KOH.
Potassium Iodate, 0.05 M:
Weigh accurately 10.7 g of potassium iodate, previously dried at 110º to constant weight, in sufficient water to produce 1000 ml. Standardize the solution in the following manner.
Dilute 25.0 ml of the solution to 100 ml with water and to 20.0 ml of this solution add 2 g of potassium iodide and 10 ml of 1 M sulphuric acid. Titrate with 0.1 M sodium thiosulphate using 1 ml of starch solution, added towards the end of the titration, as indicator. 1 ml of 0.1 M sodium thiosulphate is equivalent to 0.003566 g of KIO3.
Potassium Permanganate, 0.02 M:
Dissolve 3.2 g of potassium permanganate in 1000 ml of water, heat on a water-bath for 1 hour, allow to stand for 2 days and filter through glass wool. Standardize the solution in the following manner.
To 25.0 ml of the solution in a glass-stoppered flask add 2 g of potassium iodide, followed by 10 ml of 1 M sulphuric acid. Titrate the liberated iodine with 0.1 M sodium thiosulphate, using 3 ml of starch solution, added towards the end of the titration, as indicator. Perform a blank determination and make necessary correction. 1 ml of 0.1 M sodium thiosulphate is equivalent to 0.003161 g of KMnO4.
Store protected from light.
Silver Nitrate, 0.1 M:
Disslove 17.0 g in sufficient water to produce 1000 ml. Standardize the solution in the following manner.
Weigh accurately about 0.1 g of sodium chloride, previously dried at 110° for 2 hours and dissolve in 5 ml of water. Add 5 ml of acetic acid, 50 ml of methanol and 0.15 ml of eosin solution. Stir, preferably with magnetic stirrer, and titrate with the silver nitrate solution. 1 ml of 0.1 M silver nitrate is equivalent to 0.005844 g of NaCl. Store protected from light.
Sodium Dodecyl Sulphate, 0.001 M:
Dissolve 0.2884 g of sodium dodecyl sulphate, calculated with reference to the substance dried at 105° for 2 hours, in sufficient water to produce 1000 ml. Standardize the solution in the following manner.
To 50.0 ml add 15 ml of chloroform, 10 ml of 1 M sulphuric acid and 1 ml of dimethyl yellow-oracet blue solution and titrate with 0.004M benzethonium chloride, shaking vigorously and allowing the layers to separate after each addition, until the chloroform layer acquires a permanent clear green colour. 1 ml of 0.004 M benzethonium chloride is equivalent to 0.001154 g of C12H25NaO4S.
Sodium Hydroxide, 1 M:
Dissolve 42 g of sodium hydroxide in sufficient carbon dioxide-free water to produce 1000 ml. Standardize the solution in the following manner.
Weigh accurately about 5 g of potassium hydrogen phthalate, previously powdered and dried at 120° for 2 hours, and dissolve in 75 ml of carbon dioxide-free water. Add 0.1 ml of phenolphthalein solution and titrate with the sodium hydroxide solution until a permanent pink colour is produced. 1 ml of 1 M sodium hydroxide is equivalent to 0.2042 g of C8H5KO4. Store in bottles with well-fitted suitable stoppers which prevent access to atmospheric carbon dioxide. Volumetric solutions of sodium hydroxide must be restandardize frequently. Solutions of lower concentrations are prepared by quantitatively diluting accurately measured volumes of 0.1 M sodium hydroxide with sufficient carbon dioxide-free water to give the desired concentration.
Sodium Hydroxide, 0.1 M Ethanolic:
Dissolve 4.2 g of sodium hydroxide in 5 ml of water and add sufficient aldehyde-free ethanol to produce 1000 ml. Allow the solution to stand in a tightly-stoppered bottle for 24 hours. Then quickly decant the clear supernatant liquid into a suitable, tightly-closed container. Standardize the solution in the following manner.
Weigh accurately about 0.6 g of benzoic acid, dissolve in a mixture of 30 ml of ethanol (95 per cent) and 6 ml of water and titrate with the ethanolic sodium hydroxide solution, using 0.2 ml of thymolphthalein solution as indicator. 1 ml of 0.1 M ethanolic sodium hydroxide is equivalent to 0.01221g of C7H6O2. Store protected from light and moisture.
Sodium Methoxide, 0.1 M:
Cool 150 ml of anhydrous methanol in ice water and add, in small portions, about 2.5 g of freshly cut sodium. When the metal has dissolved, add sufficient toluene, previously dried over sodium wire, to produce 1000 ml. Standardize the solution in the following manner immediately before use.
Weigh accurately about 0.4 g of benzoic acid, dissolve in 80 ml of dimethylformamide, add 0.15 ml of thymolphthalein solution and titrate with sodium methoxide solution to a blue end-point. Protect the solution from atmospheric carbon dioxide throughout the titration. Perform a blank determination and make any necessary correction. 1 ml of 0.1 M sodium methoxide is equivalent to 0.01221 g of C7H6O2. Store protected from carbon dioxide and moisture.
Sodium Nitrite, 0.1 M: D
issolve 7.5 g of sodium nitrite in sufficient water to produce 1000 ml. Standardize the solution in the following manner.
Dissolve 0.3 g of sulphanilic acid in 50 ml of 2 M hydrochloric acid, add 3 g of potassium bromide, cool in ice and titrate with the sodium nitrite solution determining the end-point potentiometrically. 1 ml of 0.1 M sodium nitrite is equivalent to 0.01732 g of
C6H7NO3S.
Sodium Thiosulphate, 0.1 M:
Dissolve 25 g of sodium thiosulphate and 0.2 g of sodium carbonate in carbon dioxide-free water and dilute to 1000 ml with the same solvent. Standardize the solution in the following manner.
Dissolve 0.200 g of potassium bromate, weighed accurately, in sufficient water to produce 250.0 ml. To 50.0 ml of this solution add 2 g of potassium iodide and 3 ml of 2 M hydrochloric acid and titrate with the sodium thiosulphate solution using starch solution, added towards the end of the titration, as indicator until the blue colour is discharged. 1 ml of 0.1 M sodium thiosulphate is equivalent to 0.002784 g of KBrO3. Restandardize the solution frequently.
Sulphuric Acid, 0.5 M:
Add slowly, with stirring, 30 ml of sulphuric acid to about 1000 ml of water, allow to cool 25° and standardize against anhydrous sodium carbonate as described under 1 M hydrochloric acid. 1 ml of 0.5 M sulphuric acid is equivalent to 0.05299 g of Na2CO3.
Sulphuric Acid, 0.25 M Ethanolic:
Add slowly, with stirring, 13.9 ml of sulphuric acid to a sufficient quantity of ethanol to produce 1000 ml. Cool and standardize against anhydrous sodium carbonate as described under 0.5 M methanolic hydrochloric acid.
Tetrabutylammonium Hydroxide, 0.1 M:
Dissolve 40 g of tetrabutylammonium iodide in 90 ml of dehydrated methanol in a glass-stoppered flask. Place in an ice-bath, add 20 g of powdered silver oxide, insert the stopper and agitate vigorously for 1 hour. Centrifuge a few ml, and test the supernatant liquid for iodides. If the test is positive, add an additional 2 g of silver oxide and continue to stand for 30 minutes with intermittent agitation. When all of the iodide has reacted, filter through fine sintered-glass filter. Rinse the flask and filter with three quantities, each of 50 ml, of anhydrous toluene. Add the washings of the filtrate and dilute to 1000 ml with anhydrous toluene. Flush the solution for 10 minutes with dry, carbon dioxide-free nitrogen. Store protected from carbon dioxide and moisture, and discard after 60 days. Alternatively, prepare the solution by diluting a suitable volume of commercially available tetrabutylammonium hydroxide solution in methanol with a mixture of four volumes of anhydrous toluene and 1 volume of dehydrated methanol. Standardize the solution in the following manner immediately before use.
Weigh accurately about 0.4 g of benzoic acid, dissolve in 80 ml of dimethylformamide, add a few drops of a 1 per cent w/v solution of thymol blue in dimethylformamide and titrate with the tetrabutylammonium hydroxide solution to a blue endpoint.
Protect the solution from atmospheric carbon dioxide throughout the titration. Perform a blank determination and make any necessary correction. 1 ml of 0.1 M tetrabutylammonium hydroxide is equivalent to 0.01221 g of C7H6O2.
Titanium Trichloride, 0.1 M:
Dilute 100 ml of titanium trichloride solution with 200 ml of hydrochloric acid and add sufficient freshly boiled and cooled water to produce 1000 ml. Standardize the solution immediately before use by titrating with it, in an atmosphere of carbon dioxide, 25 ml of 0.1 M ferric ammonium sulphate acidified with sulphuric acid, using ammonium thiocyanate solution, adjust before the endpoint, as indicator. 1 ml of 0.1 M ferric ammonium sulphate is equivalent to 0.01543 g of TiCl3.
Zinc Chloride, 0.1 M:
Dissolve 6.6 g of granulated zinc, previously washed with 0.1 M hydrochloric acid and then with water, in the minimum amount of 2 M hydrochloric acid and add sufficient water to produce 1000 ml. Standardize the solution in the following manner.
To 25.0 ml of the solution add 4 g of ammonium acetate and 25 ml of water. Add 50 mg of xylenol orange mixture and sufficient hexamine, and titrate with 0.1 M disodium edentate until the colour changes to yellow. 1 ml of 0.1 M disodium edetate is equivalent to 0.013630 g of ZnCl2.
Zinc Sulphate, 0.1 M:
Dissolve 29 g of zinc sulphate in sufficient water to produce 1000 ml. Standardize the solution in the following manner.
To 20.0 ml add 5 ml of 2 M acetic acid and carry out the method for the determination of zinc. 1 ml of 0.1 M disodium edetate is equivalent to 0.02875 g of ZnSO4,7H2O.
