(troe meth' a meen).
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C4H11NO3 121.14

1,3-Propanediol, 2-amino-2-(hydroxymethyl)-.
2-Amino-2-(hydroxymethyl)-1,3-propanediol [77-86-1].
» Tromethamine contains not less than 99.0 percent and not more than 101.0 percent of C4H11NO3, calculated on the dried basis.
Packaging and storage— Preserve in tight containers.
USP Reference standards 11
USP Tromethamine RS Click to View Structure
B: To 4.5 mL of a saturated solution of salicylaldehyde add 0.5 mL of glacial acetic acid, and mix. Add 4.0 mL of a solution of Tromethamine (1 in 5), and mix: a yellow color is produced.
C: To 0.5 mL of a 4 in 10 solution of ceric ammonium nitrate in 2 N nitric acid add 3 mL of water and 0.5 mL of a solution of Tromethamine (1 in 5), and mix: the color changes from light yellow to orange.
Melting range 741: between 168 and 172.
pH 791: between 10.0 and 11.5, in a solution (1 in 20).
Loss on drying 731 Dry it at 105 for 3 hours: it loses not more than 1.0% of its weight.
Residue on ignition 281: not more than 0.1%.
Assay— Dissolve about 250 mg of Tromethamine, accurately weighed, in 100 mL of water, add bromocresol purple TS, and titrate with 0.1 N hydrochloric acid VS to a yellow endpoint. Each mL of 0.1 N hydrochloric acid is equivalent to 12.11 mg of C4H11NO3.
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(SM32010) Monographs - Small Molecules 3
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USP35–NF30 Page 4966
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