The extraction of turmeric was
successfully done using dichloromethane with the
aid of magnetic stirrer and heat at reflux for 60 min.
The extract was filtered and concentrated in water
bath at 50 o
C, and the residue obtained was further
redissolved in hexane. Plates were developed three
times using dichloromethane–MeOH (99: 1 v/v).
The RF value obtained for curcumin was 0.52.
The ability of two-dimensional TLC for
analysis of three curcuminoids in the rhizomes of C.
phaeocaulis, C. kwangsiensis, C. wenyujin and C.
longa has been investigated by Zhang et al. (2008).
The chromatographic separation was achieved on
silica gel 60F254 plate using eluent mixture of
CHCl3–MeOH–formic acid (20:1:0.2, v/v/v) and
petroleum ether–ethyl acetate (9:1,v/v) for twice
development. The chromatogram spots were colorized
using 1% vanillin–in sulfuric acid. The presence of
curcuminoids in these plants was semi-quantified
densitometrically at λ scan and λ reference of 518
and 800 nm, respectively. The authors stated that the
developed TLC method can be used as a technique
for quality control of Curcuma rhizomes. Table 1
compiled some of the published research related to
the use of TLC and its high performance (HPTLC)
for analysis of curcuminoids.