How to prepare standard solution
Composition of Prepared Reagents
Reagent grade chemicals should be used in the preparation of all solutions. These reagents should be prepared only in a well-equipped laboratory, under the supervision of an experienced chemist. It is advisable to purchase these solutions from a laboratory supply house if complete laboratory facilities are not available for their preparation.
Acetic Acid-Sodium Acetate Buffer
A solution of 136 gm sodium acetate trihydrate, in distilled water. Add 40 ml 1N acetic acid and dilute to 1 liter.
Alkaline Potassium Iodide
Dissolve 700-g potassium hydroxide in 700 ml distilled water and cool. Dissolve 150-g potassium iodide in 200 ml distilled water and cool. Mix the two solutions and dilute to 1.0 liter with distilled water.
Aluminium standard
A solution of 8.792 g aluminium potassium sulfate (potassium alum), AlK (SO4)2. 12H2O in distilled water diluted to 1 liter in a volumetric flask. Solution is 500 ppm as Al. Appropriate dilutions of this stock should be made immediately prior to constructing the calibration curve.
Ammonium Molybdate Solution
Add 53-ml sulfuric acid to 500 ml-de-ionized water. Add 18.4 g ammonium molybdate (NH4)6 Mo7O24 . 4H2O to solution. Mix and adjust volume to 1 liter with deionized water.
Ammonium standard
A 1000-ppm ammonia as N solution is prepared by dissolving 3.819 g anhydrous NH4Cl in 1liter of ammonia-free water.
Ascorbic Acid Solution
A solution of 0.1-g ascorbic acid in distilled water.
Barium Chloride, 10%
A 10.0 per cent solution of barium chloride in distilled water.
Bromothymol Blue Indicator
Dissolve 0.04 g of 3'3" dibromothymolsulfonephthalein-sodium salt in 90 ml of distilled water. Adjust pH to 6.8 with sodium hydroxide or hydrochloric acid. Make up final volume to 100 ml with distilled water.
Brucine Reagent
Brucine is a toxic alkaloid. For this reason the reagent is best purchased commercially.
Calcium Indicator
A dispersion of 0.20-g murexide (ammonium purpurate) in 100 g C.P. potassium chloride, ground so it will pass through a 30 mesh screen.
Calcium Standard Solution, 50 ppm as CaCO3
Weigh 1.00 g anhydrous CaCO3 into a 500 ml Erlenmeyer flask. Place a funnel in the neck of the flask and add 50% hydrochloric acid until all the salt has dissolved. Add 200 ml deionized water and boil for a few minutes to expel carbon dioxide. Dilute to 1 litre with deionized water. This solution is 1000 ppm as CaCO3. Dilute quantitatively 1:20 for a 50 ppm CaCO3 standard.
Chelant Blank Reagent
Double-distilled water.
Chelant Buffer Reagent (Dry)
40 per cent anhydrous sodium borate powder, 60 per cent boric acid powder. Powders are uniformly mixed.
Chelant Demand Reagent P1
A difficult reagent to prepare. Commercially available preparations are recommended.
Chelant Demand Reagent P2
A difficult reagent to prepare. Commercially available preparations are recommended.
Chelant Demand Reagent P3
A difficult reagent to prepare. Commercially available preparations are recommended.
Chelant Demand Reagent P4
A difficult reagent to prepare. Commercially available preparations are recommended.
Chelant Indicator No.1
Dissolve 1 g of methylene blue in about 500 ml of distilled water and dilute to 1 litre.
Chelant Indicator No.2
Dissolve 1 g of 1-(2-pyridylazo)-2 naphthol in 500 ml of isopropyl alcohol (99 per cent).
Dilute to 1 litre with isopropyl alcohol.
Chelant Indicator No.3
Dissolve 0.6 g of 1-(1hydroxy-4- methyl-2 phenolazo) -2 naphthol-4-sulfonic acid) in 500 ml of distilled water. Dilute to 1 litre with distilled water when completely dissolved.
Chelant Liquid Buffer
Dilute 405 ml of concentrated ammonium hydroxide to 1 litre with distilled water.
Chromate Reagent
Dissolve 2.0 g of 1,5-diphenylcarbazide in 1 litre of anhydrous isopropanol containing 1 ml of syrupy phosphoric acid. Note : the compound dissolves slowly with stirring and the alcohol lost due to evaporation must be replaced.
Chromate Standard
Dissolve 127 mg of potassium dichromate in distilled water and dilute to 1 litre. Solution is 100 ppm as CrO4.
Chromium Reagent
Dissolve 27 g of cerric sulfate, H4Ce (SO4)4 in 6N sulfuric acid and make up to 1 litre with the 6N acid. The 6N acid is not standardized and it is prepared by pouring 168 ml of concentrated sulfuric acid into 1 litre of distilled water.
Conductivity Standard
Dissolve 2.5 g of C.P. sodium chloride that has been dried to constant weight at 105c in a litre of distilled water. This standard has a specific conductance of 4600 micromhos at 25C.
Copper Reagent P1
Add 238 ml of concentrated ammonium hydroxide into 500 ml of distilled water. Slowly add 111 ml of glacial acetic acid. Make up to a final volume of 1 litre with distilled water.
Copper Reagent P2
Add one level brass dipper of sodium diethyldithicarbamate to 100 ml of distilled water.
Dissolve powder completely. This solution is stable for two weeks.
Copper Standard
Dissolve 3.93 g of CuSO4. 5H2O in 1 litre of water. This is a 1000 ppm, as Cu, standard.
DPD Indicator
A 0.1 per cent solution of DPD oxalate in a litre of chlorine-free distilled water containing 8 ml of 25 per cent sulfuric acid and 200 mg disodium ethlenediamine tetraacetate dihydrate. Store in a brown glass stoppered bottle, and discard when discolored. (The buffer and indicator are commercially available as a combined reagent in stable powder form.)
Disodium Ethylenediamine Tetraacetate (EDTA) Solution, 0.01M
A solution of 3.7 g of di-sodium ethylenediamine tetraacetate dihydrate in distilled water, diluted to 1 liter.
EDTA Standard Solution
Dilute 500 ml of Hardness Titrating Solution, (1 ml = 1 mg CaCO3) to 1 litre with distilled
water.
EDTA Titrating Solution
Dissolve 2.150 g of zinc acetate Zn (C2H3O2)2. 2H2O in approximately 900 ml of distilled water., dilute to 2 litres.
Eriochrome Cyanine R Dye Indicator
Dissolve 300 mg of the dye in 50 ml distilled water. Adjust the pH from about 9 to 2.9 with 1:1 acetic acid. Dilute to 1 liter with distille water. This reagent solution is stable for at least six months.
Glycerol Sulfate Solution
Weigh out 50.0 g of NaCl and 26.5g of AlCl3.6H2O. Dissolve the salts in approximately 500-ml of distilled water. By means of a graduate, transfer 20 ml of concentrated HCl to the solution. Dilute to 750 ml with distilled water. Pour 250 ml of glycerin into the solution and mix well.
Hardness Buffer Reagent
The dry hardness buffer is prepared using special solvents, mixing, evaporation and grinding. Special equipment is necessary.
A liquid buffer reagent, stable for approximately three months, can be prepared by dissolving 10 g sodium hydroxide, 10 g sodium sulfide, 40 g sodium tetraborate (Na2B4O7.10H2O) and 10 g sodium potassium tartrate (NaKC4H4O6. 4H2O) in a liter of distilled water. In the hardness test, 0.5 ml of the liquid buffer is used.
Hardness Indicator
The dry hardness indicator is prepared using special solvents, mixing and grinding. Special equipment is necessary. A liquid hardness indicator, stable for approximately three months, can be prepared by dissolving 10 g Eriochrome black T in 300 ml of 0.2 per cent sodium carbonate solution. Then dilute to 1.0 litre with isopropyl alcohol (99 per cent), adjusting pH to 9.0 with 0.1N sodium carbonate. In the hardness test, use four to six drops of the liquid indicator.
Hardness Titrating Solution
1 ml = 1 mg CaCO3
A distilled water solution of 4.0 g disodium ethylene diaminetetraacetate dihydrate and
0.86 g sodium hydroxide per liter, standardized so that 1 ml = 1 mg CaCo3
Hydrazine Reagent A
Dissolve 4 g of paradimethylaminobenzaldehyde powder in 200 ml of methyl alcohol (absolute). When dissolved, add 15 mg of concentrated hydrochloric acid.
Hydrazine Reagent B
Mix 200-ml methyl alcohol and 15 ml concentrate hydrochloric acid.
Hydrazine Reagent C
Dilute 74 ml concentrated hydrochloric acid to 1 litre with distilled water.
Hydrazine Reagent D
Pipet 10 ml hydrazine standard solution into 1 litre volumetric flask. Make up to 1 litre with reagent C. One ml of Reagent D is equal to 0.001-mg hydrazine as N2H4.
Hydrazine Standard
A solution of 0.328-g hydrazine hydrochloride (N2H4.2HCL) in 100 ml distilled water and 74 ml concentrated hydrochloric acid. Dilute to 1 litre with distilled water.
Hydrochloric Acid, 0.02N
A solution of hydrochloric acid in distilled water standardized to 0.02N.
Hydrochloric Acid, 2%
Add 20 ml concentrated acid to 800 ml-deionized water. Adjust volume to 1 litre with deionized water.
Hydrochloric Acid, 10%
A 10.0 per cent by volume solution of concentrated hydrochloric acid in distilled water.
Hydrochloric Acid, 50 %
A 50 per cent by volume solution of concentrated hydrochloric acid in distilled water.
Hydrogen Peroxide, 3%
Commercially available.
Iodide Crystals
Reagent grade potassium iodide.
Iron Reagent
Dissolved 100 g of hydroxylamine hydrochloride in 200 ml of distilled water. Adjust the pH to 8.0 with 20 per cent NaOH. Makeup to 600 ml. Add 100 ml of glacial acetic acid. Dissolved 22 g of Al (NO3) 3. 9H2O in 150 ml of distilled water. Add 4.0 g of disodium ethylenediamine tetraacetate dihydrate and dissolve it completely. Pour this solution into the above solution and make final volume up to 1 litre.
Iron Standard
Add slowly 20 ml concentrated H2SO4 to 50 ml distilled water and dissolve 1.404g Fe (NH4)2(SO4)2. 6H2O. Add 0.1N KMnO4 drop-wise until a faint pink color persists. Dilute to 1 liter with iron free distilled water. Solution is 200 ppm as Fe.
Manganous Sulfate
Dissolve 480g MnSO4.4H2O in distilled water, filter, and dilute to 1 litre.
Methyl Orange Indicator
A 0.05 per cent solution of methyl orange in distilled water.
Methyl Purple Indicator
A commercially available proprietary dispersion of an organic dye sensitive to essentially the same pH range as methyl orange indicator.
Molybdate Reagent
Dissolve 25 g (NH4)6 Mo7O24.4H2O in 175 ml deionized water. Cautiously add 280 ml concentrated H2SO4 to 400 ml deionized water. Cool and add to other solution. Bring to 1 litre with deionized water.
NTA Standard Solution
Dilute 780 ml of Hardness Titrating Solutions (1 ml = 1 mg CaCO3) to 1 litre with distilled
water.
NTA Titrating Solution
Dissolve 2.08 g of cadmium acetate Cd (C2H3O2)2. 2H2O in 500 ml of distilled water and makeup final volume to 1 litre with distilled water.
Nessler Reagent
A solution of 4 N NaOH containing 100 g HgI2 and 70 g KI per litre. Prepare using ammonia-free water.
(Caution: Toxic Avoid Ingestion)
Neutral Barium Chloride Solution
Dissolve 50.0 g of barium chloride and 80.0 of tetrasodium ethylenediamine tetraacetate into approximately 900 ml of distilled water. Adjust the pH of the solution to 7.0 using dilute HCl. Dilute the solution to 1 litre with distilled water.
Nitrate Standard
Dissolve 1.631 g of oven dried (105C) potassium nitrate (KNO3) in 1 litre of distilled water. Solution is 1000 ppm as NO3.
Nitric Acid, 10 %
A 10 per cent by volume solution of concentrated nitric acid in distilled water.
Orthophenenthroline Reagent
Dissolve 1.0 g of orthophenanthroline monohydrate in 1 litre of distilled water.
Phenolphthalein Indicator
0.5 per cent solution of phenolphthalein in 50 per cent ethyl alcohol.
Phosphate Buffer Solution
A solution of 24 g anhydrous disodium hydrogen phosphate and 46 g anhydrous potassium dihydrogen phosphate in distilled water. Combine with 100 ml distilled water in which 800-mg of disodium ethylenediamine tetraacetate dihydrate have been dissolved. Dilute to 1 litre with distilled water and add 20-mg mercuric chloride.
Phosphate Standard
Dissolve 0.143 g KH2PO4 in 800 ml deionized water. Bring to 1-litre total volume.
Solution is 100 ppm as PO4.
Potassium chromate indicator
A 5.0 per cent solution of potassium chromate in distilled water.
Potassium Iodide-Iodate
1 ml=0.5 mg SO3
A solution of 0.31 g sodium bicarbonate. 435-g potassium iodide and 0.45g potassium iodate per litre, standardized to 0.0125N.
Potassium Permanganate 0.1N
An aged solution of potassium permanganate in distilled water, standardized to 0.1N
Potassium Permanganate Solution
A solution containing 891 mg potassium permanganate/100 ml of distilled water. Dilute 10.00ml of the stock solution to 100 ml with distilled water in a volumetric flask. When 1.00 ml of this solution is diluted to 100 ml with distilled water, a chlorine equivalent of 1.00 ppm will be produced in the DPD reaction.
Silica Standard
Add 4.74 g Na2SiO3 . 9H2O to 800 ml of deionized water. Bring to 1 litre with deionized water. Solution is 1000 ppm as SiO2.
Silver Nitrate
1 ml = 1 mg Cl
An approximately 0.03N solution of silver nitrate in distilled water, standardized so that 1 ml=1 mg Cl.
Sodium Carbonate 0.02N
Accurately weigh 1.06 g of dry Na2CO3 and dilute to 1 litre in a volumetric flask with distilled water.
Sodium Carbonate 0.045N
Dissolve 2.407 g oven-dried Na2CO3 in 1 litre of carbon dioxide free water. Seal tightly and store in a Pyrex bottle.
Sodium Fluoride Solution 3%
Dissolved 30 g of sodium fluoride in approximately 900 ml of distilled water. Dilute to 1 litre with distilled water when completely dissolved.
Sodium hydroxide 1.0N
A solution of sodium hydroxide in distilled water standardized to 1.0N.
Sodium hydroxide 14N
Dissolved 560.0 g NaOH in approximately 500 ml distilled water. Cool. Dilute to 1 litre with distilled water.
Sodium Sulfite Solution
Add 170 g of sodium sulfite (Na2SO3) to 800 ml deionized water and make up volume to 1 litre with deionized water.
Sodium Thiosulfate, 0.1N
A solution of sodium thiosulfate in distilled water, standardized to 0.1N
Stannous Chloride Reagent
Dissolve 2.5 g of fresh SnCl2. 2H2O in 100 ml glycerol. Heat in a water bath and stir with a glass rod to hasten solution. This reagent is stable and requires neither preservatives nor special storage.
Starch Indicator
A 0.5 per cent solution of c.p. starch in distilled water.
Starfamic Indicator
A proprietary dispersion of cold water soluble starch in a crystalline acid medium.
Sulfamic Acid
Reagent grade sulfamic acid.
Sulfate Standard
Dissolve 148 mg of anhydrous sodium sulfate in distilled water and dilute to 1 litre.
Solution is 100 ppm as SO4.
Sulfite Indicator
A proprietary dispersion of cold water soluble starch in a crystalline acid medium. (U.S. Patent No. 2,963,442)
Sulfuric Acid 0.02N
A solution of sulfuric acid in distilled water standardized to 0.02N.
Sulfuric Acid 1.0N
A solution of sulfuric acid in distilled water, standardized to 1.0N.
Sulfuric Acid 6.0N
A solution of sulfuric acid in distilled water, standardized to 6.0N.
Sulfuric Acid 5%
A 5.0 per cent by volume solution of concentrated sulfuric acid in distilled water.
Sulfuric Acid 10%
A 10 per cent by volume solution of concentrated sulfuric acid in distilled water.
Sulfuric Acid 30%
A 30 per cent by volume solution of concentrated sulfuric acid in distilled water.
Sulfuric Acid 50%
A 50 per cent by volume solution of concentrated sulfuric acid in distilled water.
Zinc Reagent P1
Dissolve 150 g of sodium acetate in approximately 500 ml of double-distilled water. Add 15 g of sodium fluoride and stir until dissolved. Add 400 ml of double-distilled water. Adjust the pH to exactly 6.2 using glacial acetic acid and a pH meter. Store in a plastic container.
Zinc Reagent P2
Add 10 g of 3,5 dimethyltetrahydro 1,3,5, -2H-thiadiazine -2-thione to 1 litre of double- distilled water. Mix. Allow the solution to stand tightly stoppered for at least an hour. Decant the clear supernatant into a glass container. The clear solution is stable for a week.
Zinc Reagent P3
Prepare a 0.3 per cent aqueous solution of xylenol orange-tetra sodium salt. Solution is unstable and must be prepared daily.
Homogeneous commercial mixtures of dye and inert diluents are stable for one year. The powder mixture can be encapsulated.
Zinc Standard
Dissolve 0.1000g of zinc metal (30 mesh) in 1 ml of 1:1 hydrochloric acid. (Warming is necessary). Dilute the dissolved metal to 1.0 litre with distilled water. Store in glass bottle. Solution is 100 ppm Zn.