Diethanolamine

2,2′-Iminobisethanol; C₄H₁₁NO₂ = 105.1 (111-42-2)

Viscous, clear, slightly yellow liquid or deliquescent crystals melting at about 28°, very soluble in water, in acetone and in methanol.

, about 1.09.

pH(2.2.3) 10.0 to 11.5 for a 5.0% w/v solution.

Diethanolamine used in the test for alkaline phosphatase complies with the following additional test.

Ethanolamine Not more than 1.0% w/w when determined in the following manner. Dissolve 1.00 g of 3-aminopropanol (internal standard) in sufficient acetone to produce 10 mL (solution A). Dissolve 0.5 g of ethanolamine in sufficient acetone to produce 10 mL (solution B). Carry out the method for gas chromatography, Appendix III B, using the following solutions. For solution (1) add 1 mL of solution A to 5 g of the substance being examined and dilute to 10 mL with acetone. For solution (2) dissolve 5 g of the substance being examined in sufficient acetone to produce 10 mL. For solution (3) add 1 mL of solution A to 0.5 mL of solution B and dilute to 10 mL with acetone. Prepare solution (4) in the same manner as solution (3) but adding 1 mL of solution B in place of 0.5 mL of solution B. Prepare solution (5) in the same manner as solution (3) but adding 2 mL of solution B in place of 0.5 mL of solution B.

The chromatographic procedure may be carried out using a column (1 m × 4 mm) packed with diphenylphenylene oxidepolymer (180 to 250 µm) and using 40 mL per minute as the flow rate of the carrier gas. Maintain the temperature of the column at 125° for 3 minutes and then raise to 300° at a rate of 12° per minute. Maintain the temperature of the injection port at 250° and that of the detector at 280°.