Agriculture Reference
In-Depth Information
foreseeable future, although false-positive results were found in a high number of
cases for these methods [11]. A striking example is the rapid microbiological assays
used routinely by dairies to screen milk inexpensively and rapidly for residues of
antimicrobial drugs. In the United Kingdom alone, dairy companies run millions of
such assays per year, with a test duration of only minutes from sampling to result.
These tests are widely used internationally by dairies for completeness.
1.1.3 Food Safety Classi
cations
Food safety analysis can be broadly classi
ed and grouped based on the residues or
analytes and food matrices, accepting that there will be some degree of crossover
between groups. Based on the analytes, it can be classi
ed to pesticide residues, drug
residues, mycotoxins and environment pollutants, and other industrial chemicals.
Based on food matrices, the most accepted classi
cation of groups consists of high-
moisture foods, low-moisture foods, and fatty foods. Examples of such matrices are
fruits and vegetables, dry grains (wheat, rice, bean, etc.), and tissues, including
sh
and meat.
Food safety analysis methods can be further divided into two categories:
screening methods and con
rmation methods. The regulatory agencies and inter-
national standard organizations have clear guidelines for screening methods and
con
rmation methods. The requirements are slightly different for both, depending
on the residues to be analyzed, matrix, risk factor, and techniques available. A
screening method is qualitative or semiquantitative in nature, comprises establish-
ment of those residues likely to be present based on an interpretation of the raw
data, and tries to avoid false negatives as much as possible. A false negative rate of
5% is accepted for both the EU and the US FDA [12,13]. A con
rmation method
can provide unequivocal con
rmation of the identity of the residue and may also
con
rm the quantity present on residues found in screening. Therefore, an analyst
has to use appropriate guidelines to develop a new method based on the regulation,
residue category, and matrices and to provide expert advice on the
findings to those
commissioning the analysis.
1.1.4
“
High Throughput
”
De
nition
The
concept has become popular in the pharmaceutical industry
after combinatorial chemistry was introduced for drug discovery [14], such as in
“
“
high throughput
”
high-throughput screening
”
and
“
high-throughput drug analysis.
”
However,
“
high-throughput analysis for food safety
”
has only recently drawn more atten-
tion, especially after China
'
s melamine milk crisis and Taiwan
'
sphthalates
scandal.
Although there is no numeric de
in the
pharmaceutical industry, the standardized sample plate of 96-, 384-, or even 1536-
well plates can indicate how quickly many analyses can be completed. Compared
with single digits of targets in drug screening, food analysis often involves multiclass
compounds ranging from a few dozens to a few hundred targets. All these kinds of
nition of
“
high-throughput screening
”
