We introduce the notion of pure Q-solvable algebra. The quantum matrices, q
uantum Weyl algebra, U-q(n) are the examples. It is proved that the skew fi
eld of fractions of a pure e-solvable algebra R is isomorphic to the skew f
ield of twisted rational functions. This is a quantum version of the Gelfan
d-Kirillov conjecture for solvable algebraic Lie algebras. (C) 2001 Academi
c Press.