Product Description

pKa: < 2, 2.7, 8.8, and 9.51

Melting Point: 241 C, with decomposition

Synonym: EGTA

EGTA is a reagent that is used to chelate Ca2+ in the presence of Mg2+.2

EGTA chelates Ca2+ at a ratio of 1:1. The log (stability constants) for several cations are as follows:1

Mg = 5.2

Ca = 11.0

Mn = 12.1

Fe = 11.8

Co = 12.3

Ni = 11.8

Cu = 17.7

Zn = 12.9

A protocol for the determination of free calcium in calcium-EGTA solutions has been reported.3 A procedure for making a calibration standard for calcium ion concentration, with detection accurate to 10 mM in a mixture of EGTA, HEDTA, and NTA has been reported.4

EGTA can be used as an anti-coagulant when dissolved at 1 g per 100 ml blood. EDTA is more commonly used for the same purpose; either agent chelates the calcium ion from blood.

Precautions and Disclaimer

For Laboratory Use Only. Not for drug, household or other uses.

Preparation Instructions

Solubility at:

pH 8.38 > 0.52 M

pH 5.4 > 0.48 M

pH 4.5 = 0.45 M

pH 4.2 = 0.42 M

pH 4.0 = 0.31 M

A saturated solution at room temperature was found to be 2 mM in EGTA and had a pH of 2.72. The solubility in 1 M NaOH was 10 g/90 ml, and yielded a clear, colorless solution.