Amygdaline is a heteroglycoside consisting from benzaldehde-cyanohydrine and gentobiose /formula C6H5CH/CN/-O-C12H21O10/. You can obtain it via step-vise ethanol extraction of fine meal of disintegrated dry almonds /dry the meal in a desicator over an anhydrone or 99 % H2SO4 and not in an owen/.
1/If you submitt isolated amygdaline to gravimetric analysis, or better to HPLC you can calculate the amount of -CN in your substrate from the quantitative data and the quantity of dry almonds or kernel meals.
2/ It is also possible to release and determine HCN via acid hydrolyse of dry meal of almonds or isolated amygdaline. Total hydrolysis of amygdaline yielding benzalhyde, glucose and toxic! The HCN release might be performed with in 3% H2SO4. Tis step should be carried out in sealed glas tube at approx. 60-80 oC. After hydrolysis cool the reaction mixture to subzero temperature, unseal the tube in a digestorium, neutralize and transer the contents into the volumetric flask.
HCN in the sample can be determined by colorimetric methods / e.g. after addition of FeSO4 yielding Fe/CN/6 stabile comlex/, or indirectly from amount of released benzaldehyde DNPH-one after precipitation with 2,4 dinitrophenylhydrazine.
Note: direct analysis of the oil is complicated and not the best idea. Maybe hot continual extraction of oil with H2O might be the first step. You should find a partrition coefficient of amygdaline in the system H2/ oil. If it is high enough, extract the amygdaline and determine HCN according to the steps 1 or 2.
Do´nt mention it.
It is possibly a standard methodic and verified by practice. In my opinion it is, however, too complicated.
My proposal follows only from my knowledge of amygdaline and its properties and reactions.
You may also determine amount of amygdaline with HPLC directly in the ethanol extract, or to use an aliquot of the amygdaline hydrolyzate and determine benzadehyde GLC or HLPC. In this case hydrolysis of the extract should be performed in a mixture of water and ethanol containing 3%H2SO4 /due to solubility of benzaldehyde. H2SO4 should be neutralized before chromatographic determination.
Calculation of HCN contents is easy since hydrolysis of amygdaline yields equimolar amounts of benzaldehyde, glucose and HCN.
Regards,
R.S.
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