Annex VII STANDARD METHOD FOR DETERMINING FLOTATION INDEX (ARTICLE 7(3))

Prepare an aqueous solution of sodium nitrate of specific weight 1,25 and conserve it at 35 °C.

Place in the solution 100 grains of maize from a representative sample of maximum moisture content 14,5 %.

Shake the solution at 30 second intervals for five minutes to eliminate air bubbles.

Separate the floating from the submerged grains and count them.

The flotation index is calulated as follows:

Flotation index for trial = (number of floating grains/number of submerged grains) × 100

Repeat five times.

The flotation index is the arithmetic mean for the five trials excluding the two extreme values.