Extraction and analysis of amesto acids from apple tree material

Two extractants are suggested for use with apple tree material: ethanol/water/N‐HCI, 75 : 25 :2 by vol., for all tissues except leaves; and ethanol‐chloroform‐water, 12 : 5 : 3 by vol., for leaves. The ability of these solutions to extract the nitrogenous constituents of apple tree tissues has been compared with that of other extractants. Some improvements are suggested for the analysis of amides by hydrolysis and of amino acids by thin‐layer electrophoresis/thin‐layer chromatography. Details of the recommended methods for freeze‐drying and milling tree material and for the extraction and quantitative analysis of amino acids are also given.