Agriculture Reference
In-Depth Information
consumers [6]. In consequence, the control of the concentrations of these substances
in the
final food product has become a cause of concern for governments.
In the food safety framework, the EU and other countries such as the U.S. or
Canada have strictly regulated and controlled the use of VDs, including growth
promoters, particularly in food-producing animal species, by publishing different
regulations and directives [7,8]. In addition, some of these substances, such as
diethylstilbestrol, nitrofurans, and chloramphenicol, have been banned in farming
production in the EU because either they are toxic compounds or complete toxico-
logical dossiers are not available, whereas others, such as tetracyclines or sulfona-
mides, have been authorized as long as their concentrations in food of animal origin
are below certain established limits.
In consequence, it is necessary to develop sensitive analytical methods that comply
with the current legislation, allowing the control and determination of authorized and
banned VDs in food and thus ensuring the safety of the food products derived
from treated animals. In this sense, a high number of analytical methods have been
developed to allow the identi
11].
Traditionally, these methods have been based on microbiological assays or immuno-
assay techniques [12,13]. However, they have been replaced by more selective and
sensitive techniques, such as liquid chromatography (LC) coupled with
cation of VD residues in several kinds of foodstuff [9
-
uorescence or
UV detection [14,15]. These conventional detection techniques have been gradually
replaced by mass spectrometry (MS) detection, bearing in mind that public health
agencies rely on detection by MS for unambiguous con
rmation of VDs in food-
stuffs [16]. Thus, LC coupled with single quadrupole (Q) or triple quadrupole (QqQ) has
been used for this purpose, although Q
-
MS has been highly replaced by QqQ tandem
MS (QqQ
-
MS/MS), which provides more con
dence in analyte identi
cation and
quanti
cation.
LC coupled with Q
MS/MS (low-resolution mass spectrometry
analyzers, (LRMS)) has been widely used for the determination of a relatively lower
number of compounds (i.e.,
-
MS and QqQ
-
200 compounds in a single run) [9,11]. However,
LRMS has limitations due to the fact that there are
100
-
250 different chemical substances,
which can be employed in husbandry practices, apart from other
>
(mixtures
of low amounts of several substances that exert a synergistic effect) [17], which have
also to be monitored. This may imply a sensitivity decrease in multiresidue methods
when conventional LC
“
cocktails
”
MS/MS is used. Besides, the need for developing quick
and low-cost methods that cover all the established requirements by the regulations for
residue control requires that typical methods and instruments be replaced by new ones,
including high-resolution mass spectrometry analyzers (HRMS) such as time of
-
QqQ
-
flight
(TOF), hybrid quadrupole-time of
flight (QqTOF), or Orbitrap.
6.2 VETERINARY DRUG LEGISLATION
Bearing in mind the problems concerning the widespread use of VDs in livestock
production, several measures have been taken by national governments to control
their use in feed and their presence in food products and the environment as residues.
