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y, , 5.14 Complexometric Titration, ’5.8 DETERMINATION OF CALCIUM GLUCONATE_ ~ ) |, Requirements:, Calcium gluconate, disodium edetate, mordant black I indicator, ammonia butte, (oH, 10), calcium chloride, magnesium sulphate, distilled water, volumetric flask, conical fas, , burette, pipette etc., Principle: }, Complexometric titration (sometimes chelatometry) is a form of volumetric analysis iy, which the formation of a coloured complex is used to indicate the end point of a titration,, Complexometric titrations are particularly useful for the determination of a mixture of, different metal ions in solution. An indicator capable of producing an unambiguous colour, change is usually used to detect the end-point of the titration., , Pharmaceutical Analysis, , , , , , Ca’? + Eriochrome Black T/Mordant Black II (Indicator), (Wine red colour), , HOOC—Ch, ], a _7CHCOOH, N—CH,—CH,—N, HOOC—CH, CH,COOH, , (Titrant: Ethylene diamine tetra acetic acid/ EDTA), , Ca-EDTA Complex + Free Mordant black II indicator, (Colourless) + (Blue colour), (Final colour at the end point is Blue), , Preparation of Reagents:, Preparation of 0.05 M CyoHi4N2Na20g 2H20:, , Weigh accurately 18.612 g of CigHig4N2Na20g 2H,0. Dissolve in 200 ml distilled wa, and make up the final volume upto 1000 ml in a volumetric flask., Preparation of bromine water:, , Dissolve 3 ml Br2 in distilled water and make up the final volume upto 100 ml., Preparation of 2N NaOH:, , Accurately weigh and dissolve 8.0 g of NaOH in distilled water and make up the fel, volume upto 100 ml., Preparation of ammonia buffer (pH 10):, , Accurately weigh and dissolve 5.4 g of NH,Cl in 70 ml of SN ammonia and dilute wil, , water to 100 ml.

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pharmaceutical Analysis 5.15 Complexometric Titrations, , experimental Methodology:, , 4, Accurately weight about 800 mg of granulated Zn and dissolve in 12 ml of dil. HCI by, gentle warming. Add approximate 5 drops of bromine water and warm the solution till, the boiling., , 2, —xcess amount of bromine will be removed after boiling; then cool the resulting solution., Add distilled water to produce the final volume 200 ml., , 3, Pipette out 20 ml of the above Prepared solutio, 2.N NaOH solution and monitored by pH paper,, , 4. Dilute the neutralized solution upto 150 ml, buffer solution (pH 10) to dissolve the Precipit:, in excess., , 5. Add 3-4 drops of mordant black-Il/eriochrom, and colour of the solution turns blackish-blue,, , 6. Titrate the above solution with Prepared sodium edetate solution until the colour turns, to light green and note the end point., , 7. Accurately weigh about 0.8 g of calcium, water containing 5mi dil. HCl., , n into a conical flask and neutralize with, , and add sufficient amount of ammonia, ate (if any) and add 5 ml of buffer solution, , eblack T (EBT)/solochrome black indicator, , gluconate and dissolve in 150 ml of distilled, , Add 5 ml of 0.05 M MgSO, solution and 10 ml of ammonia buffer solution (PH 10)., , Titrate the content of the flask against 0.05 M disodium edetate solution using mordant, black Il indicator until the solution turns green., Calculations:, , ZnClp=Zn?* = 1000 m!IM, 65.38g Zn = 1000mIM, 3.269g Zn = 1000 ml0.05M, 0.003269 g Zn = 1 ml of 0.05 M disodium ethylenediaminetetracetate, 0.08 g of Zn is present in the 20 ml solution., So, ea = 24.47 ml.0.05 M EDTA., , 0,05 x 24.47, Volume of EDTA consumed, Fach ml of 0.05 Mm CioHy4NgNa2Og 2H20 = 0.02242 g of CygH22CaOy4H2O, Volume of EDTA x Actual molarity of EDTA x 0.02242 x 100, Weight of Cy2H22CaO4 (in g) x 0.05 (Expected molarity of EDTA), , Actual Molarity of EDTA =, , * Purity of CizH22CaQi4 =, Resutt:, , Percentage Purity of the given sample of calcium gluconate was found to be x %., , a

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Pharmaceutical Analysis * 5.16 Complexometric Titrations, , , , , , , , , , , Colour at the end point, , int, Colour at the end poin ‘Uehtgresn), , (Light green), , 0.05 EDTA, , Mordant Black-II, (3-4 drops), , 10 ml buffer, 5 ml 0.05 M MgSO,, , 145 ml DW +, 5 ml dil. HCI, , 0.8 g CygH,,CaOj,, , Mordant Black-II, (3-4 drops), Ammonia buffer (pH 10), , 20 ml of Zn solution, , Step1 Step 2, , Fig. 5.2: Assay of C12H22CaO,, - HO, , , , [5.9 DETER, , Requirements:, , , , Magnesium gluconate, disodium edetate, mordant black I indicator, ammonia buffer *, (pH 10), magnesium sulphate, distilled water, volumetric flask, conical flask, burette, pipett®, etc., , Principle:, , Complexometric titration (sometimes chelatometry) is a form of volumetric analysis i”, which the formation of a coloured complex is used to indicate the end point of a titration, Complexometric titrations are particularly useful for the determination of a mixture of, different metal ions in solution. An indicator capable of producing an unambiguous colou!, change is usually used to detect the end-point of the titration., , A