Agriculture Reference
In-Depth Information
The most comprehensive study dealing with the high-throughput ambient MS
analysis of mycotoxins in cereals was performed by Vaclavik et al. [32], who used a
DART ion source coupled with an Orbitrap mass spectrometer. In the
rst step, the
DART ionization ef
ciency of various mycotoxins was investigated. Of the 24 tested
mycotoxins, 11 target analytes could be ef
ciently ionized by the DART technology.
Only poor ionization of major trichothecenes A (T2 and HT2) and some a
atoxins
(AFB1 and AFB2) was achieved by DART. The ionization of OTA and other
mycotoxins such as ergot alkaloids, fumonisins, and D3G was not possible under the
experimental conditions employed. The samples of test cereals were processed by a
modi
ed QuEChERS extraction procedure and, due to relatively high ion signal
ed by means of matrix-matched standards with
addition of isotope-labeled internal standards (Figure 8.4). The data generated by
DART
fluctuations, analytes were quanti
ed reference materials were in good agreement with
those obtained by a UHPLC
-
MS analysis of certi
TOFMS method. The method was shown to be
applicable for high-throughput detection of DON and ZON at limits established in
the EU for unprocessed wheat and maize.
Another study described rapid DART
-
-
TOFMS analysis of DON in beer samples
following immunoaf
nity cleanup and sample preconcentration [75]. In a paper
focused on UHPLC
-
MS analysis of multiple mycotoxins in beer, DART
-
Orbitrap
MS
cation effect achieved by
acetonitrile-induced precipitation of some matrix components [62]. The application of
the DESI ionization technique coupled with an ion-trap mass spectrometer was
demonstrated for the determination of mycotoxins in a review by Maragos et al. [76].
Fumonisin B1 (0.2 ng) was deposited on the surface of maize kernels and, after
drying, was easily detected as [M
fingerprinting was employed to document the puri
H]
+
ion by DESI
MS. Moreover, after subjecting
the DESI-analyzed kernels to a germination test, 9 of 10 were found viable. Such
results document the nondestructive nature of the DESI technique.
+
-
8.4.3
Ion Mobility Spectrometry
Ion mobility spectrometry (IMS) is an analytical technique that has gained widespread
use in many applications dealing with the detection of contaminants due to its
excellent sensitivity and rapid operation. Its main advantages include low detection
limits, rapid response, simplicity, portability, and relatively low cost. IMS is a gas-
phase ion separation technique in which ion mobility measurement is based on the
drift velocities of ions in an electric
field at ambient pressure. The technique is similar
to TOFMS except that it operates under atmospheric pressure [77,78].
The IMS approach has been applied to the detection of mycotoxins in only a few
studies. The
atoxins B1 and B2 in pistachios by
means of corona discharge IMS [78]. In another study, the mycotoxin ZON and its
metabolites
first study focused on determining a
-ZAL)
were analyzed by means of a novel high-field asymmetric waveform ion mobility
spectrometry (FAIMS) method coupled with electrospray ionization (ESI). In com-
parison with ordinary ESI
α
-zearalenol (
α
-ZOL),
β
-zearalenol (
β
-ZOL), and
α
-zearalanol (
α
cantly lower detection
limits were obtained [79]. Khalesi et al. [80] described the IMS determination of OTA
-
MS performance parameters, signi
