Agriculture Reference
In-Depth Information
pollutants have priority to be detected. The congeners of PCBs constantly migrate in
soil, water, air, and other environmental matrices and eventually bioaccumulate [30].
The analyses of PCBs in fat and tissues were mainly based on GC
-
ECD [31
-
34],
GC
MS/MS [37], and immunoassay had also been applied to
assay PCBs in animal fat [38]. The sample preparation methods were SPE [39],
ASE [40], SFE (supercritical
-
MS [35,36], and GC
-
fluid extraction) [41], MSPD [36], and other techniques.
Bordet et al. [39] reported an interlaboratory study on the determination of 21
organochlorines, 6 pyrethroid pesticides, and 7 PCBs in milk,
fish, eggs, and beef fat
by GC. SPE with C18 and Florisil cartridges was used for cleanup of the samples after
cryogenic extraction. The results showed the method had acceptable intra- and
interlaboratory precision. Zhang et al. [40] developed a simultaneous extraction
and cleanup method for the determination of polybrominated diphenyl ethers
(PBDEs) and PCBs in sheep liver tissue by selective pressurized liquid extraction
(SPLE). GC
-
MS was used to analyze PBDEs and PCBs. Related factors in extraction
ef
ciency were optimized, for example, extraction solvent, temperature, pressure, and
so on. The method developed compared favorably with traditional extraction methods
(e.g., Soxhlet extraction, off-line pressurized liquid extraction (PLE), and ultrasonic
and heating extraction methods).
5.1.4 Phthalate Esters
PAEs are a class of environmental estrogens. In 1995, the World Health Organization
(WHO) promulgated chemicals that can disrupt human endocrine function and must
be controlled, and PAEs were in the list. Six PAEs are included in the
“
list of priority
monitoring pollutants
by the U.S. EPA: dimethyl phthalate (DMP), diethyl phthalate
(DEP), dibutyl phthalate (DBP), phthalate bis-2-ethylhexyl ester (DEHP), dioctyl
phthalate (DOP), and butyl benzyl phthalate (BBP) [42]. Many studies have been
reported on the analysis of PAEs in water and other environmental samples. The
most frequently applied methods were GC and GC-MS [43
”
-
46], and the sample
preparation methods were LLE, SPE, SPME, and others [47
50]. Prieto et al. [49]
established a method based on stir bar sorptive extraction (SBSE) and GC
-
MS to
analyze several environmental pollutants in water samples. Sixteen PAHs, 12 PCBs,
6 PAEs, and 3 nonylphenols (NPs) could be determined simultaneously with LODs of
0.1
-
10 ng/l. Lin et al. [47] assayed 14 PAEs in six types of animal viscus by ultrasonic
extraction and Florisil SPE cleanup. GC
-
-
EI-MS
-
SIMwas used to determine the PAE
residues. LODs of 12 PAEs were
g/kg, and LODs of dimethyl glycol
phthalate and bis(2-ethoxyethyl) phthalate were 3.30 and 2.25
<
1.74
μ
μ
g/kg, respectively.
5.1.5 Multiclass and Multiresidue Analyses
We have been continuously committed to multiclass, multiresidue, and high-
throughput analyses of pesticides and chemical pollutants in complex matrices,
including animal tissues. As early as 1994, we established the multiresidue analytical
method for nine pyrethroids in chicken, beef, mutton, and pork. The samples were
