University:
Swansea University
Course:
PM134 | Microbiology
Academic year:

2023
Views:

264

Pages:

2
Author:

Sanjeev K

DATE: 12-1-2023 ESTIMATION OF REDUCING SUGAR BY DINITRO SALICILIC ACID METHOD AIM To determine the concentration of reducing sugar by Dinitro Salicylic method PRINCIPLE Reduing sugars have the property to redme many 9 the reagente. Ene imin reagent is 3,5-di nitrosalicylic acid (DNS) 3,5-DNS in alkaline solution is reduced to 3 amino is nitrosalicylii aid. Water is used up as a reactant and oxygen gas is released during dur the reaction The formation 3-ammo-5 nitro sallylic and resudi ith a chang in the amount 540 nm. q light absorbed at wavelength MATERIALS REQUIRED UV-Vis spectrophotometer; test tubes, 3,5-DNS, dusulle, water, pipette, water bath, test tube stand, 40% Rochelle salt, wuwose standard. PROCEDURE Preparation & DNS reagent Solution A-109 3 DNS was dusolved in 200ml 2m Naon with w warming and rigorous stirring. Solution B-300g sodium potassium tartrate to tha hydrate was alssolved in 500 ml destilled water. Both solutions were mixed al were made up to IL Crith distilled water. 1. First take & test tubes, clean it and then the trebas are mariced as blank, 1, 2, 3, 4, 5, UK, and UK 2 2. In the blank tube 3 ml of dudilled water and DNS reagent in added 3. In the tube marked al 1,05mly Glucose stam dard, as mig duulled water and 3 mig DNS neagent is added. 4. In me tuve marked as 2.0.1 ml f std glucose 2 mot of distilled water and 3ml & DNS reagent 5 In the tube muked as 3, 1.5 ml & Stet gliwose, imi a distilled water and 3.0 ml of BNG reagem is added 6. In the tube marked cove, Imig is added. durilled water 2.0mlg ind 30 m ml of DNS reagent as A Standard glu- 7. In the tube marked as 5, 2.5 ml 9 std-glucose, 05ml 9 destilled water 4 3.0ml of DNS reagent is added 8. In the tube marked as UKI, adddımi q unknown guiox 1, a omi og dustilled water and 3.0m 3 DNS heagent 9. In the tube marke a as Uk 2, added aml of unknow gluvox 2, 1.0 ml gcustill a water and 30ml & DNS Preagent 10. All the bubu were kept is water hatn for batn for 5 min It After 5 min au the tubes are taken out and after sometime added imly 401. Rochelle saut to all the tuber 12. Measure the absorbame at 510nm and note the readings RESULT The concentration of the unknown Solution I is 90µg The concentration of the unknown Solution 2 is 165 ug