chemia - Studia

RAPID AND SIMPLE ANALYSIS OF ALLICIN IN ALLIUM SPECIES BY LC-CIS-MS/MS
Table 1. Analytical characteristics of several reported HPLC or LC/MS
methods for the determination of ALC in vegetal extracts
Extraction Mobile phase Detection Run time Observations Ref.
(min)
Extraction
at room
temperature
Sodium
dihydrogenphosphate+
heptanesulfonic acid /
HPLC-UV, 208 nm 30 Other ALC
derivatives
also analysed
6
Ultrasonic
extraction/
centrifugation
Turboextraction,
liquid-liquid
extraction
Supercritical
fluid extraction
Vortexsonication
acetonitrile, gradient
Water-methanol,
isocratic
Water-methanol,
isocratic
Water-acetonitrile
gradient
Water-methanol,
isocratic
HPLC-UV, 254 nm 20 - 7
HPLC-UV, 254 nm
after post-column
photochemical
derivatisation
10 - 8
LC-APCI-MS 25 Other ALC 9
derivatives
also analysed
HPLC-UV, 220 nm 15 - 10
The pseudo-molecular mass spectra (MS 1 , no fragmentation applied)
obtained for ALC-silver complex (Fig. 2) shows two main ions with m/z 449
and 451, corresponding to a molecular formula [2*ALC+H 2 O+Ag] + , in which
the silver ion is surrounded by two ALC molecules and one molecule of water.
The two major ions from the spectra (m/z 449 and 451) are the adducts formed
by the two silver isotopes. The mass spectrum of ALC-silver complex (MS 2 ,
fragmentation applied) is shown in Fig. 3 and the proposed main fragmentation
pathways in Fig. 4.
Intens.
x10 6
+MS, 0.1-0.1min #(17-21)
3.0
2.5
449.0
451.0
2.0
1.5
1.0
0.5
0.0
447.0
441.9
465.5
425 430 435 440 445 450 455 460 465 m/z
Figure 2. Pseudo-molecular (MS 1 ) non-reactive ion on mass spectra of
ALC-silver complex
299