Agriculture Reference
In-Depth Information
examined for each species of production animal (cows, pigs, horses, goats, sheep,
poultry, game,
es
the different groups of veterinary medicinal products to be screened for (antimicro-
bials, anabolics, antiparasitics, etc.). In either type of monitoring, positive (i.e.,
noncompliant) or suspect samples must be properly separated from all negative
(compliant) samples. For the meticulous implementation of these regulations and to
curb the possibility of veterinary residue-tainted animal foods, proper identi
fish, etc.) and their products (milk, eggs, and honey). It also speci
cation
and quanti
c and technical bases for these
controls depend on the development, validation, and application of appropriate
reliable analytical methods with excellent sensitivities for the criteria and require-
ments related to these regulations laid down in several European Commission
Decision and Guidelines [20
cation tools are needed. Thus, the scienti
22].
Bearing in mind the public health protection, it is logical to consider that both the
regulations set for the control on food safety and the worrying perception that the
consumers may have on the security of food tend to make proposals for building a
faster, easier, but also broader and safer scope for this control. One of the cheapest
but reliable routes for it will be using high-throughput methods designed to screen
large numbers of harmful substances. It will maximize the food safety information
obtained from a single sample and it will minimize the sets of samples to be
collected.
-
7.3 CHOOSING A STRATEGY: TARGETED OR NONTARGETED ANALYSIS?
The most widely used MS technologies to con
rm the presence of residues of
veterinary drugs in routine/
eld laboratories are mainly QqQ LC
-
MS systems, hybrid
quadrupole-ion trap (QTrap) LC
-
MS systems, and ion trap (IT) LC
-
MS systems.
These systems are capable of analyses at a unit mass resolution (0.5
-
1 Da). They are
generally dedicated to targeted quantitative con
rmation analysis using SRM or
MRM, providing high sensitivity and selectivity for the target compounds, but they
are much less sensitive in full scan mode. The analytes of interest are selected before
acquisition and the acquisition parameters are optimized so that only veterinary
residues included in the
list are detected. While these are the currently
prevailing methods, in recent years, some scientists have started to opt for high-
resolution mass spectrometers in veterinary medicinal residue analysis by means of
accurate mass measurement via ToF, Orbitrap, and FTICR mass analyzers, as
mentioned in Section 7.1. Among these analyzers, FTICR has the highest resolving
power, which mainly depends on the strength of the magnet. For example, a resolution
of two million can be achieved with a 6 T magnet. However, FTICR is more
expensive and incurs high maintenance compared with other mass analyzer systems.
Alternately combining two different analyzers in a single instrument (hybridization),
for example, Q
“
pretargeted
”
Orbitrap), increases the
instrument performance by way of different possible scan modes. For comparison
sake, ToF and Orbitrap analyzers have approximate resolving powers ranging from
30,000 for the ToF to
-
ToF, LTQ
-
Orbitrap, or Q
-
Exactive (Q
-
>
100,000 for the Orbitrap device. Figure 7.1 shows the
