Estimation of Reducing Sugar by Dinitro Salicylic Acid Method

DATE : 12.1.2023 ESTIMATION OF REDUCING SUGAR BY DINITRO SALICYLIC ACID METHOD AIM TO determine the concentration of reducing sugar by Dinitro Salicylic method PRINCIPLE Reducing sugars have the property to redue many of the reagents. One sun reagent is 3,5-di nitrosalicylic and (DNS). 3,5- DNS in alkaline solution is redue a to 3 amino 5 nitro salicylic aud. water is used up as a realtant and oxygen gas is released during the reaction results The in formation a 3-ammo-5 nitrosalicylic acid chang in of the amount of light absorbed at wavelength 540 nm. MATERIALS REQUIRED UV-VIS spectrophotometer test tubes, 3,5-DNS distulle water , pipette, water bath, test tube stand, 40% Rochelle salt, alluose standard. PROCEDURE Preparation of DNS reagent Solution A - 10g of DNS was dissolved in 200ml 2M NaOH with warming and rigon stirring. hydrate was arssolved g in 500 ml Solution B - 300 sodium potassium distilled tartrate water tetra- Both solutions were mixed al were made up to IL with distilled water. 1. First take 8 test tubes, clean it and then the tubes are mariad as blank, 1, 2, 3, 4,5, UK, and UK2

2. In the blank whe 3 ml of distilled water and DNS 3. reagent In the tube is added marked as 1,05ml of surrose DNS Stan- dard, 2.5 ml of distilled wall and 3 ml of A In the tube marked as 2.0.1 ml of Std. glucose reagent is added 2 ml of distilled water and 3 ml of DNS reagent is In the tube marked as 3, 1.5 ml of Std glumose, 1 ml of distilled waue and 3.0ml of DNb reagent is added 6. In the tube marke d as A, 2.0mlg standard glu- cose, 1mlq discilled water and 30 ml of DNS reagent is added 7. In the tube marked as 5, 2.5 ml of Std glucose, 05ml of destille a water m 3. 0ml of DNS reagent is added 8. In the tube marked as UKI, ad delim of unknown gumox 1, 2. oml of distilled water an a 3.0ml of DNS reagent 9. In the tube marke a as UK2, added 2ml of unknow glumose 2, 1.0 ml of dustille a water and 3.0ml of DNS reagent 10 All the tubes were kept is water bath for 5 min 11 After 5 min all the tuhes are taken out and after sometime added 'ml of 401. Rochell salt to all the tubes 12. Measure the absorbance at 5101 n m an a note the readings. RESULT The concentration of the unknown Solution I is 90 90mg The concentration of the unknown solution 2 IS 165 Mg