The alkaloid content can be determined gravimetrically by method of Haborne,
1973). For which 5 g of each sample is to weighed using a weighing balance and dispersed into 50 ml of 10% acetic acid solution in ethanol. The mixture is well shaken and then allow to stand for about 4 h before it is filtered. The filtrate is then evaporated to one quarter of its original volume on hot plate. Concentrated ammonium hydroxide is added drop wise in order to precipitate the alkaloids. A pre-weighed filter paper is used to filter off the precipitate and it was then washed with 1% ammonium hydroxide
solution. The filter paper containing the precipitate is dried on an oven at 60 oC for 30 min, transfer into desiccators to cool and then reweigh until a constant weight is obtained. The constant weight is recorded. The weight of the alkaloid can be determined by weight difference of the filter paper and expressed as a percentage of the sample weight analyzed
Determination of Total Alkaloids
Alkaloid subjected to quantitative estimation by gravimetrically according to Woo et al., (1977)
About (10 g) of the plant powder were extracted with 90 % ethanol till exhaustion (tested with Mayer's reagent). The alcoholic extract of the plant was concentrated under reduced pressure at a temperature not exceeding 40 °C acidified with HCl (3 %), and filtered; the filtrate obtained was extracted with chloroform to remove undesirable matters. The acidic aqueous layer was adjusted to alkaline media with ammonia and the liberated alkaloid bases were extracted with chloroform till exhaustion (tested by Mayer and Dragendroff's reagents). The chloroform extract was filtered over anhydrous sodium sulphate and evaporated under reduced pressure till dryness, then weighed it to calculate the percent w/w (Woo et al., 1977).
Is it possible to use that gravimetric methods to extract alkaloids from liquid phertilizer?
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