AOAC Official Method
Aminopyrine
First Action 1923
Final Action
A. Qualitative Tests
(a) Dissolve g test portion in 2 mL H2O and add few drops of
yellow HNO3 (containing HNO2). Purplish blue solution is produced.
(b) Dissolve g test portion in 2 mL H2O and add 1 mL 10%
FeCl3 solution. Purple to violet color develops, which becomes red
on addition of H2SO4 (1 + 9).
(c) Dissolve g test portion in 2 mL H2O and add few drops of
5% AgNO3 solution. After few s, purple to violet color is produced,
and on standing, deposit of metallic Ag results (useful for detecting
aminopyrine in antipyrine).
(d) Dissolve – g test portion in 2 mL H2O, add 1 or 2 drops
% NaNO2 solution and few drops of H2SO4 (1 + 9), and shake few
seconds. Purplish blue color develops and then gradually fades, leav-
ing colorless solution. Excess NaNO2 destroys aminopyrine color. On
addition of few more drops of NaNO2 solution and dilute H2SO4, yel-
lowish green color remains after purple disappears if antipyrine is
present. (Useful for detecting antipyrine in presence of aminopyrine.)
References: JAOAC 7, 29(1923); 8, 40(1924); 8, 544(1925).
B. Quantitative Method
Place 1 g powdered test portion in 100 mL volumetric flask, add
60 mL .05M H2SO4 , (see ), and shake several minutes
to ensure complete solution of aminopyrine. Dilute to volume with
.05M H2SO4. Filter, if not clear, through dry filter, rejecting first part
of filtrate. Pipet 20 mL aliquot of test solution or filtrate into separa-
tor; make distinctly alkaline with either NH4OH or 5% NaOH; and
extract with 20, 15, 10, 10, and 5 mL portions CHCl3. Combine
CHCl3 extracts in second separator and wash with 2 mL H2O. Filter
CHCl3 solution into weighed beaker through cotton pledget satu-
rated with CHCl3. Extract wash H2O with 5 mL CHCl3 and add this
to combined CHCl3 extracts. Evaporate combined CHCl3 extracts
just to dryness on H2O bath with aid of air current and dry residue
10 min at 100°C. Cool in desiccator, and weigh as aminopyrine.
Identify aminopyrine by its mp, –109°C, and qualitative tests,
A, or microchemical tests, Table (see ).
References: JAOAC 11, 51, 350(1928); 23, 60, 742(1940).
CAS-58-15-1 (aminopyrine)
© 2000 AOAC INTERNATIONAL
