Method for the estimation of Fulvic acid content

Method for the estimation of  Fulvic acid content

Solvents  & chemical Required :

Methyl Alcohol L.R. Grade

Ethyl Acetate L.R. Grade

Chloroform L.R. Grade

Acetone L.R. Grade

Activated Carbon

0.1 N Sodium Hydroxide Solution

2 N Hydrochloric Acid

Nitrogen gas

Glass wares and Apparatus Required  :

Round Bottom Flask (250mL capacity)

Beaker 250mL

Separating funnel

Stoppered cylinder 50mL

Evaporating dish – 100mL capacity

Procedure :

Weigh accurately about 10gm of dry extract powder or 15gm raw material (20#) in a round bottom flask. Add 50 mL chloroform and reflux for 30 minutes on water bath. Decant & discard chloroform layer. Add 50mL of ethyl acetate to the residue & reflux for 30 minutes on water bath. Decant & discard the ethyl acetate layer. Add 50mL of methyl alcohol and again reflux for 30 minutes on water bath. Decant and discard the methyl alcohol layer. Take residue and dissolve it in 200mL of 0.1N sodium hydroxide and sake thoroughly. Pass nitrogen gas in this alkali solution for 5-6 minutes & keep over night. Filter through Whatman No.1 filter paper. Take filtrate and make it acidic up to pH 3.0 to 3.5 with (2N HCl). Keep this solution for over night. Add charcoal (3.5 gm) to this solution and reflux for 1 hour. Filter under vacuum. Take charcoal and dry up to complete removal of water. Suspend the charcoal part in 100 mL of acetone and shake well. Heat for 15 minutes and filter it in a tared petridish. Evaporate acetone part and dry in an oven 105⁰C upto constant weight. 

Calculation:

Percentage of Fulvic acid (w/w) is calculated as:

            Weight of residue    

   =     ---------------------------  X 100

                         Weight of sample

Method for the estimation of  Fulvic acid content By Titration

Solvents  & chemical Required :

Distilled water,Indigosulphonic acid, Potassium permanganate solution,0.1M Hydrochloric acid

Glass wares and Apparatus Required  :

Funnel,1000 ml conical flask,Measuring cylinder 100ml, 500ml,Burette,Pipette

Procedure :

1. Take 0.1 gm sample and add 50 ml of water, add 1ml 0.1M Hydrochloric acid.
2. Sonicate for 15 minutes, and filter through filter paper. Wash Filter paper by 25 ml distilled water. Collect all filtrate.
3. Add distilled water to make solution 750 ml. Add 25ml of Indigosulphonic acid solution as an indicator.
4. Titrate with constant stirring against N/10 Potassium Permanganate solution till colour change from blue to golden-yellow colour.
5.  1 ml of N/10 pottasium permanganate is equivalent to 0.001701 gm of Fulvic compounds, calculated as a Galic acid.
6. Run a blank test by Titrating 25 ml of Indigosulphonic acid in 750 ml of water as Blank.

Calculation:

Calculate the percentage of  Fulvic acid (w/w) is calculated as:

                      ( A – B)  X  0.001701 X 100 x N

 Assay =   ---------------------------------------------------

                                  W  X 0.1

A  = Volume of 0.1N KMnO4 consumed in titration (Test)

B  = Volume of 0.1N KMnO4 consumed in titration (Blank)

W = Weight of material taken in gm

N  = Normality of Potassium permanganate

Preparation of Indigosulphonic acid : Weigh 500mg Indigo caramine indicator in a volumetric  flask. Add 50ml Conc. Sulphuric acid and make up it with water to 1000ml.