Agriculture Reference
In-Depth Information
degradation products and metabolites, which is important for risk assessment
with respect to persistence and toxicology [139].
The actual practise of the laboratories around the word dedicated to the
analysis of residues of growth-promoting agents and veterinary drugs in food
of animal origin, shown that more than 80% of the applied analytical
procedures are LC-MS based - with the LC part usually involving a gradient
run on an alkyl-bound silica column [105]. Until recently the most frequently
used mass detection technique was singlestage quadrupole MS. Today, it is
rapidly being superseded by triple-stage quadrupole (QqQ-MS) and ion-trap
(IT-MS
n
) [140].
The application of advanced LC-MS technologies to food contaminants
and residues detection has attained the determination of a broader range of
compounds with higher sensitivity, selectivity and specificity. Consequently,
the application of LC-MS allowed more comprehensive assessment of food
safety with the determination of food contaminants and residues at trace level.
Detection and characterization of emerging food contaminants with
demonstrated detrimental effects on human health is a major concern in
modern Food Safety fully supported by the application of LC-MS/MS. One of
the most important trends is to develop generic methods able to extract as
many contaminants as possible and to detect all of them simultaneously [141].
On the different mass analyzers applied in the target analysis, triple
quadrupole (QqQ) is the most widely used analytical tool. Some analytical
methods have been developed for analyzing different classes of metabolites
and degradation products of food contaminants in food matrices and human
body fluids. LC-MS
2
(QqQ) has mostly been applied to the determination of
target metabolites using the selected reaction monitoring (SRM) and achieving
limits of detection of around l to 0.01 µg kg
-1
[142].
Conventional ion trap (IT) provides sensitive full-scan mass spectra and
has the ability to perform MS
n
with n>2 experiments, which improve its ability
to characterize structurally and to confirm the identity of metabolites.
However, sensitivity is one order of magnitude lower than that of QqQ
instruments. IT instruments have mainly been applied to characterizing the
metabolism of food contaminants in healthy individuals who have received
known doses of the food contaminants [143-144].
Quadrupole linear IT (QqLIT) is a system that combines fully functional
QqQ and LIT-MS within the same platform. In addition to standard QqQ
capabilities (i.e. very sensitive SRM), QqLIT is capable of producing MS/MS
spectral information useful for structure elucidation. An elegant solution for
