Waters ACQUITY UPC^2 BEH 2-EP (2-ethylpyridine) column with dimensions of
150 3.0 mm i.d. and 1.7μm particle size. The mobile phase consisted of CO 2 as
solvent A, and isopropanol: acetonitrile (80:20) with 1% water as solvent B.
The PDA was set to scan from 190–400, and 220 nm was used for the quantifi-
cation. Mass spectrometry was performed using a Waters ACQUITY single
quadrupole mass spectrometer (Waters Corporation, Milford, MA, USA). The MS
electrospray ionization (ESI) source was operated in full scan mode (positive and
negative) in a mass range from 100 to 800 amu. The validated method has a better
sensitivity and shorter run time than GC/MS methods. The method is faster
(10 min) with a better resolution and compound identification. Multivariate sta-
tistical analysis including principal component analysis (PCA) and partial least
squares-discriminant analysis (PLS-DA) were used to differentiate between the
cannabis samples (Wang et al. 2016 ).
7.5.4 High Performance Thin Layer Chromatography
(HPTLC)
High Performance Thin Layer Chromatography (HPTLC) is one of the important
applied techniques in phytochemical analysis, herbal drug quantification, andfinger
print analysis. It is simple, low-cost and allows analysis of many samples in parallel
with the possibility of multiple detection. Normal and reversed phase HPTLC plates
could be used.
Four cannabinoids, THC, CBD, CBN, and CBC were identified and determined
using HPTLC in two commercially available Japanese cannabis oils (Hemp oil and
Taima-Yu). The analysis was performed on RP-18 HPTLC plates using acetonitril
100% as a mobile phase. After development the plates were sprayed with a coloring
agent (Echtbausalz B in 0.1 M NaOH). The limit of detection (LOQ) for the four
cannabinoids is 50μg/g (Yotoriyama et al. 2005 ).
An HPTLC analytical method was developed for the determination ofΔ^9 -THC,
CBD, CBC, CBG, and THCV as well as quantification ofΔ^9 -THC and CBN in two
decarboxylated medicinal Cannabis cultivars. Si gel HPTLC plates were used and
the range of quantification was determined to be 50–500 ng, at 206 nm. This
method can be useful for forensic analysis, quality control of hemp, and quality
control of medicinal Cannabis (Fischedick et al. 2009 )
Chromatographic analysis offive neutral cannabinoids (D^9 -THC, CBN, CBD,
CBG, and CBC) has been performed on amino HPTLC plates via over
pressured-layer chromatographic technique on an OPLC BS 50 instrument
(OPLC-NIT, Budapest, Hungary). Dichloromethane was used as a developing
agent and fast blue salt B as visualization reagent. Thirty hemp samples were
analysed on a 10 cm20 cm plate within 4 min. Plates were evaluated by
7 Natural Cannabinoids of Cannabis and Methods of Analysis 179