Page 80 - Feed Lab

Suguna Management System Ver 1.0 / SOP / FQL / P2 - 10 Page 1 of 3

10. Estimation of Phosphorus

SCOPE
To estimate the Phosphorus in feed and feed stuffs by
Photoelectric colorimetric method.

PRINCIPLE
Phosphorus in the sample is converted to
phosphomolybdic acid by adding a ammonium
molybdate. Phosphomolybdic acid in the presence of
Picture-1 Picture-2
a reluctant sodium meta bisulphate and sodium
sulphite and 1-amino-2-naphthol-4-sulphonic acid
(ANSA) gives a blue colour whose intensity is
measured by photo metrically using a wavelength of
660 nm.

Apparatus
FAnalytical Balance, 1 mg / 0.1 mg accuracy
(Picture-1)
FSilica Crucible, 25 ml (Picture-2)
Picture-3 Picture-4
FBeaker, glass, 250 ml, 100 ml, 50 ml (Picture-3)
FVolumetric flask, 500 ml, 250 ml, 100 ml (Picture-4)
FVolumetric pipette, 25 ml, 10 ml (Picture-5)

FPipette, graduated, 1 ml, 5 ml, 10 ml, (Picture-6)
FTest tubes and test tube stands (Picture-7)
FPlastic funnel, 70 mm diameter (Picture-8)
FFilter paper, fluted (Picture-9)
FHot Air Oven - pre calibrated (Picture-10)
Picture-5 Picture-6
FMuffle furnace - pre calibrated (Picture-11)
FColorimeter. (Picture-12)

Prepared by : Approved by :
68 Director - Technical