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The mineral composition of apples. XI. An extraction technique suitable for the rapid determination of calcium, but not potassium and magnesium, in the fruit
Author(s) -
Perring Michael A.
Publication year - 1974
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740250302
Subject(s) - ashing , hydrochloric acid , potassium , chemistry , magnesium , calcium , extraction (chemistry) , phosphorus , chromatography , inorganic chemistry , physics , organic chemistry , quantum mechanics
Practically all the calcium could be extracted from apple tissue, provided that particle size was reduced initially by a blending procedure, by heating with 6 N‐hydrochloric acid for 10 min. Tests with commercial samples indicated that including the time required to remove the seeds, a determination of calcium could be completed within 45 min of receiving a sample of 20 apples. Potassium, phosphorus and hydrochloric acid were the main factors interfering with the determination of 0.25 to 1.25 parts/million of calcium in solutions similar to those of apple ash or extracts by emission in a flame spectrophotometer. Average proportions of these and the other main constituents of the ash were added to standard calcium solutions to overcome interferences in routine analyses after dry ashing or extraction with hydrochloric acid. Recoveries of potassium and magnesium were low when the extraction procedure was used.