S.L. 437.76 Art. 5flask with boil and keep volume with the first 30 ml of the quantity (15 and transfer to 5.1.2. 5.1.2. Weigh out the muffle and leave to - 30 ml) of to an oven at (3.1) and make to filter. Discard 5.1.3. Weigh out the muffle Treat the ash and then dry Treat the ash using warm Mix and filter the filt

Procedure 5.1. Preparation of the sample solution 5.1.1. Feeding stuffs composed exclusively of mineral substances Weigh out to the nearest mg 5 g of the sample into a 500 ml graduated 250 to 300 ml water. Add 40 ml hydrochloric acid (3.1), bring to the the liquid gently boiling for 30 minutes. Leave to cool, make up to water, mix and filter into a dry beaker through a dry pleated filter. Discard filtrate. In the presence of silica, treat 5 g of sample with a sufficient - 30 ml) of hydrochloric acid (3.2), evaporate to dryness on a water bath an oven at 105ºC for one hour. Proceed as from the third sentence of

Feeding stuffs composed predominantly of mineral substances to the nearest mg 5 g of the sample into a crucible and ash at 550ºC in furnace until an ash which is free from carbonaceous particles is obtained, cool. In order to eliminate silica, add to the ash a sufficient quantity (15 hydrochloric acid (3.2), evaporate to dryness on a water bath and transfer 105ºC for one hour. Treat the residue with 10 ml hydrochloric acid transfer to a 500 ml graduated flask using warm water. Leave to cool and volume with water. Mix and filter into a dry beaker through a dry pleated the first 30 ml of the filtrate.

Feedingstuffs composed predominantly of organic substances to the nearest mg 5 g of the sample into a crucible and ash at 550ºC in furnace until an ash which is free from carbonaceous particles is obtained. with 5 ml hydrochloric acid (3.2), evaporate to dryness on a water bath for one hour in the oven at 105ºC in order to render the silica insoluble. with 5 ml hydrochloric acid (3.1), transfer to a 250 ml graduated flask water, bring to the boil, leave to cool and make up to volume with water. into a dry beaker through a dry pleated filter. Discard the first 30 ml of

Measurement by atomic absorption the standard solution (3.5) with water, prepare at least 5 reference increasing concentration, corresponding to the optimal measuring range spectrophotometer. Add to each solution 10 ml strontium salt solution (3.4) up the volume to 100 ml with water. Dilute with water one aliquot filtrate obtained from 5.1.1, 5.1.2 or 5.1.3, so as to obtain a magnesium which is within the limits of concentration of the reference solutions. hydrochloric acid concentration of this solution must not exceed 0ꞏ4 N. Add 10 salt solution (3.4) and then make up the volume to 100 ml with water. absorption of the solution to be determined and of the reference 285ꞏ2 nm. Calculation of results the quantity of magnesium in the sample by relation to the reference Express the result as a percentage of the sample.

Repeatability difference between the results of two parallel determinations carried out on sample must not exceed 5%, in relative value.

Chapter III Determination of Crude Fibre Purpose and scope makes it possible to determine fat-free organic substances in feeding are insoluble in acid and alkaline media and are conventionally crude fibre. Principle The sample, defatted where necessary, is treated successively solutions of sulphuric acid and potassium hydroxide of specified concentrations. residue is separated by filtration on a sintered-glass filter washed, and ashed within a range of 475 to 500ºC. The loss of weight resulting corresponds to the crude fibre present in the test sample.