Agriculture Reference
In-Depth Information
cleaned up by two Florisil columns after solvent extraction, and nine pyrethroids were
analyzed by GC. LODs were 5
μ
g/kg for all insecticides (except permethrin, for which
LOD was 10
g/kg), and the recoveries were between 76.9 and 88.0% [51]. In 2006,
we established the multiresidue analysis method for 437 pesticides in animal tissues.
The analytes included different types of pesticides and chemical pollutants, for
example, organochlorines, organophosphorus, pyrethroids, carbamates, herbicides,
PCBs, PAEs, and others. In the method, 10 g animal samples (beef, mutton, pork, and
chicken) were mixed with 20 g sodium sulfate and extracted with 35 ml of cyclo-
hexane
μ
+
ethyl acetate (1
+
1) twice by blender homogenization, centrifugation, and
filtration. Evaporation was conducted and an equivalent of 5 g sample was injected
into a 400mm
×
25mm S-X3 GPC column, with cyclohexane
+
ethyl acetate (1
+
1)
as the mobile phase at a
40min fraction was collected
for subsequent analysis. For the 368 pesticides determined by GC
flow rate of 5ml/min. The 22
-
MS, the portions
collected from GPC were concentrated to 0.5ml and exchanged with 5ml hexane
twice. For the 69 pesticides determined by LC
-
-
MS/MS, the portions collected from
GPC were dissolved with acetonitrile
40) after taking the extract to
dryness with nitrogen gas. In the linear range of each pesticide, the correlation
coef
+
water (60
+
0.98, exceptions being dinobuton, linuron, and fenamiphos
sulfoxide. At the three (low, medium, and high) forti
cient was r
cation levels of 0.2
-
4800 g/kg,
recoveries fell within 40
120%. The RSDs were below 28% for all 437 pesticides.
The LODs for the method were 0.2-600 g/kg, depending on each pesticide. The LOD
and LOQ (limit of quanti
-
cation) of the method were obtained with forti
ed
pesticides of different concentrations, and a S/N ratio of
5 was the criterion for
the LOD, whereas a S/N ratio of
10 was the criterion for the LOQ [52]. In 2009, we
further studied different types of pesticides and chemical pollutants, and the number
of analytes reached 839. We also established the database of chemical pollutants,
including a GPC database for 744 pesticides, a GC
-
MS database for 541 pesticides,
and a LC
MS/MS database for 464 pesticides. The LODs of the analytes were
between 0.1 and 1600
-
g/kg [53]. We have also established high-throughput analysis
methods in other complex matrices, including honey, cereal, fruit, vegetables, tea,
Chinese herbal medicine, milk and milk powder, and others. Hundreds of pesticides
and other chemical pollutants can be analyzed by high-throughput methods with
simple and convenient sample preparation and rapid instrument analysis.
For animal tissues, although the varieties of the pesticides and chemical pollutants
in our former research had reached nearly a thousand, they were mainly pesticides,
and the matrices were animal muscles. But multiclass environmental pollutants with
different chemical and physical properties may exist in animal fats, and comprehen-
sive and universal analytical methods for detecting them have not been established
heretofore. Therefore, it is important to establish a rapid and multiresidue monitoring
technology for representative environmental pollutants, that is, POPs and chemical
pesticides, PAHs, PCBs, and PAEs. This study established the qualitative and
quantitative determination methods for 209 PCBs, 15 PAHs, 3 PAEs, and 68
pesticides in animal fat. The samples were extracted with acetonitrile followed by
GPC cleanup and online concentration. Among the 295 compounds, 209 PCBs,
μ
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