Word Origin & History. critical 1580s, censorious, from critic + -al (1). Meaning pertaining to criticism is from 1741; medical sense is from c.1600; meaning of the nature of a crisis is from 1640s; that of crucial is from 1841.
Calcium citrate is the calcium salt of citric acid. It is commonly used as a food additive (E333), usually as a preservative, but sometimes for flavor.In this sense, it is similar to sodium citrate.alcium citrate is also found in some dietary calcium supplements (e.g. Citracal).
Citrate is an anticoagulant which binds calcium in the blood. Calcium is required for blood clotting. Since it is bound up the blood cannot clot resulting in a whole blood sample, red blood cells and PLASMA. Coagulation tubes are filled with buffered tri-sodium citrate solution. Citrate concentrations of either 0.109 mol/l (3.2 %) or 0.129 mol/l (3.8 %) are available.