Agriculture Reference
In-Depth Information
15 PAHs, 3 PAEs, and 57 pesticides are analyzed by GC
-
MS/MS, endosulfan I and
endosulfan II are determined by GC
NCI-MS, and 9 pesticides, including trichlor-
phon, metsulfuron-methyl, chlortoluron, 2,4-D, bensulfuron-methyl, propanil,
-
fipronil, phoxim, and hexythiazox, are determined by LC
-
MS/MS. The LODs
of the analytes were between 0.1 and 233.0
μ
g/kg; LODs of 275 compounds were
lower than 10
g/kg, accounting for 93.2% of the total; recoveries of 259 com-
pounds were between 60 and 120%, accounting for 87.8% of the total. The RSDs of
278 compounds were below 20%, accounting for 94.2% of the total. The research
had also analyzed 633 human adipose tissue samples, in which 81 compounds were
detected. The results showed that the proposed method was suitable for the
qualitative and quantitative determination of 295 pesticides and chemical pollutants
in animal fat.
μ
5.2 EXPERIMENT
5.2.1
Instruments
In this work, we used GC-MS (Quattro micro GC), equipped with an electron impact
(EI) source (Waters, USA); GC (6890N)
-
MS (5973N), equipped with an NCI source
(Agilent, USA); LC
MS/MS (3200 Q TRAP), equipped with an electrospray
ionization (ESI) source (Applied Biosystems, USA); ASE 300 (Dionex, USA);
GPC (AccuPrep MPS), equipped with BIO-Beads S-X3, 360mm
-
×
25 mm column
(J2 Scienti
c, USA); rotary evaporator (R-205, Büchi, Switzerland), equipped with a
BP-51 vacuum cooling system (Yamato, Japan); T25 homogenizer (IKA, Germany);
N-EVAP112 nitrogen concentrator (Orgamonation Associates, USA); SA 300
oscillator (Yamato, Japan); and KDC-40 low-speed centrifuge (USTC Chuangxin
Co. Ltd.).
5.2.2 Reagents
We used acetonitrile, acetone,
n
-hexane, cyclohexane, isooctane, ethyl acetate,
dichloromethane, toluene, methanol (pesticide residue grade) (Dikma, China), and
anhydrous sodium sulfate (analytical grade), burned at 650
C for 4 h and stored in a
desiccator. Deionized water was obtained from a Milli-Q system (Millipore, USA);
Sep-Pak
NH
2
-Carb cartridge (6ml, 500mg; Waters, USA); Sep-Pak
Alumina N
cartridge (12 ml, 2 g; Water, USA); ENVI
TM
-18 cartridge (12ml, 2 g; Supelco, USA);
membrane (0.45 and 0.2
°
μ
m); standards of individual environmental pollutant
(purities
95%, LGC Promochem GmbH, Germany).
5.2.3 Preparation of Standard Solutions
Individual standard stock solutions
: Weigh 5
-
10mg (accurate to 0.1mg) standard
into a 10 ml volumetric
flask and dissolve with toluene,
n
-hexane, acetone, methanol,
