  We address the problem of the interaction of powerful laser radiation with a
transparent substance containing a low concentration of strongly absorbing
nanoparticles under the condition of Stimulated Brillouin scattering (SBS)
whose behavior in such media was unexplored. SBS energies in
N-methyl-2-pyrrolidone (NMP) and water are measured at the wavelength of 532
nm. An experimental value $g_B = 18.6 \pm 1.8$ cm/GW for a previously unknown
Brillouin gain factor of NMP is reported. A strong SBS quenching in the liquids
by graphene nanoflakes is found. SBS threshold linear dependences on graphene
absorption coefficient (concentration) are established and found suitable for
the detection of small nanoparticles quantities in water with a minimal
detectable concentration of $5 \cdot 10^{-8}$ g/ml. The effect is considered
through an electrostriction - thermal expansion antagonism induced by carbon
vapor bubbles formation. It is found to be very sensitive to changes in
density, refractive index and acoustic absorption coefficient. Using the SBS
method, their determination and the bubbling nanosecond time-scaling can be
performed. The effect is advantageous for SBS suppression when it is
undesirable in laser technologies and optical telecommunication networks.
