87 / 311
M
ASTOVSKA
ET AL
.:
J
OURNAL OF
AOAC I
NTERNATIONAL
V
OL
.
98, N
O
. 2, 2015
487
DGG / RI WKH J P/ & 3$+V VROXWLRQ DQG /
LVRRFWDQH &DS WKH YLDO DQG YRUWH[ PL[ EULHÀ\
F. Extraction and Cleanup Procedure
(
1
$GG / RI WKH J P/ & 3$+V VROXWLRQ WR
J RI WKRURXJKO\ KRPRJHQL]HG VHDIRRG VDPSOH LQ D
P/ SRO\SURS\OHQH FHQWULIXJH WXEH
(
2
9RUWH[ VDPSOH IRU V DQG OHW HTXLOLEUDWH IRU PLQ
(
3
$GG P/ P/ LQ WKH FDVH RI VKULPS RI SXUL¿HG ZDWHU
DQG P/ HWK\O DFHWDWH
(
4
6KDNH WXEH YLJRURXVO\ E\ KDQG IRU PLQ
(
5
$GG J RI PXIÀHG DQK\GURXV PDJQHVLXP VXOIDWH DQG
J VRGLXP FKORULGH DQG VHDO WKH WXEH ZHOO HQVXUH WKDW SRZGHU
GRHV QRW JHW LQWR WKH VFUHZ WKUHDGV RU ULP RI WKH WXEH
(
6
6KDNH WXEH YLJRURXVO\ E\ KDQG IRU PLQ HQVXULQJ WKDW
FU\VWDOOLQH DJJORPHUDWHV DUH EURNHQ XS VXI¿FLHQWO\ GXULQJ
VKDNLQJ
(
7
&HQWULIXJH WXEH DW ! UFI IRU PLQ
(
8
7DNH D P/ DOLTXRW RI WKH XSSHU HWK\O DFHWDWH OD\HU
DGG / LVRRFWDQH DV D NHHSHU DQG JHQWO\ HYDSRUDWH DOO HWK\O
DFHWDWH XQWLO RQO\ LVRRFWDQH DQG FR H[WUDFWHG VDPSOH IDW DUH OHIW
(
9
5HFRQVWLWXWH LQ P/ KH[DQH
(
10
&RQGLWLRQ D VLOLFD 63( FROXPQ J VLOLFD JHO ZLWK
DSSUR[LPDWHO\ J RI PXIÀHG DQK\GURXV VRGLXP VXOIDWH RQ
WKH WRS ZLWK P/ KH[DQH±GLFKORURPHWKDQH
Y Y DQG
P/ KH[DQH
(
11
$SSO\ WKH H[WUDFW LQ KH[DQH RQWR WKH VLOLFD 63( FDUWULGJH
(
12
(OXWH ZLWK KH[DQH±GLFKORURPHWKDQH
Y Y XVLQJ
YROXPH GHWHUPLQHG IRU WKH JLYHQ VLOLFD JHO 63( FDUWULGJHV
IURP WKH HOXWLRQ SUR¿OHV RI WDUJHW DQDO\WHV DQG IDW ZKLFK DUH
dependent on the silica deactivation,
see Note
(
4
EHORZ &ROOHFW
the eluent.
(
13
$GG P/ LVRRFWDQH DQG P/ HWK\O DFHWDWH WR
WKH HOXHQW DV D NHHSHU DQG JHQWO\ HYDSRUDWH GRZQ WR P/ WR
UHPRYH KH[DQH DQG GLFKORURPHWKDQH IURP WKH ¿QDO H[WUDFW
(
14
7UDQVIHU WKH ¿QDO H[WUDFW LQWR DQ DXWRVDPSOHU YLDO IRU WKH
*& 06 DQDO\VLV
Notes 1
7KH IDW FDSDFLW\ RI WKH J VLOLFD JHO 63( FROXPQ
LV DSSUR[LPDWHO\ J ,I WKH P/ HWK\O DFHWDWH H[WUDFW DOLTXRW
FRQWDLQV PRUH WKDQ J IDW LW LV QHFHVVDU\ WR XVH D VPDOOHU
DOLTXRW YROXPH WR DYRLG VDPSOH EUHDNWKURXJK GXULQJ WKH
cleanup step.
(
2
) Ethyl acetate should not be present in the extract applied
WR WKH VLOLFD FDUWULGJH EHFDXVH LW FDQ DIIHFW WKH H[WUDFW SRODULW\
WKXV SRWHQWLDOO\ UHWHQWLRQ RI IDW DQG DQDO\WHV RQ WKH VLOLFD JHO
7KH FRH[WUDFWHG IDW DQG / LVRRFWDQH DFW DV NHHSHUV GXULQJ
WKH ¿UVW HYDSRUDWLRQ VWHS VWHS
8
), thus the evaporation should
EH FRQGXFWHG JHQWO\ XQWLO WKHUH LV QR VLJQL¿FDQW FKDQJH LQ WKH
volume, i.e., until only the isooctane and coextracted fat are left
LQ WKH HYDSRUDWLRQ WXEH RU ÀDVN
(
3
$GGLWLRQ RI
P/ HWK\O DFHWDWH WR WKH HOXHQW LQ VWHS
13
is recommended for a better control of the evaporation process
DQG KLJKHU DEVROXWH UHFRYHULHV RI YRODWLOH 3$+V
(
4
7KH GHDFWLYDWLRQ DQG VWRUDJH RI VLOLFD JHO 63( FDUWULGJHV
FDQ YDU\ SRWHQWLDOO\ UHVXOWLQJ LQ GLIIHUHQW DPRXQWV RI ZDWHU LQ
the silica, thus its potentially different retention characteristics.
7KHUHIRUH LW LV LPSRUWDQW WR WHVW WKH HOXWLRQ SUR¿OHV RI 3$+V DQG
fat and determine the optimum volume of the elution solvent
to ensure adequate analyte recoveries and fat cleanup. The
IROORZLQJ SURFHGXUH LV UHFRPPHQGHG
(
a
3UHSDUH D 3$+ VROXWLRQ LQ KH[DQH E\ FRPELQLQJ
/ RI WKH :RUNLQJ 3$+ 6ROXWLRQ $ DQG P/ KH[DQH
LQ D YLDO 0L[ ZHOO DQG DSSO\ RQWR D VLOLFD 63( FROXPQ J
VLOLFD JHO ZLWK DSSUR[LPDWHO\ J RI PXIÀHG DQK\GURXV
VRGLXP VXOIDWH RQ WKH WRS ZKLFK ZDV FRQGLWLRQHG ZLWK P/
KH[DQH±GLFKORURPHWKDQH
Y Y DQG P/ KH[DQH
(
b
(OXWH ZLWK P/ KH[DQH±GLFKORURPHWKDQH
Y Y
Table 2014.08D. (
continued
)
PAH
1R RI
laboratories 1R RI UHSOLFDWHV
Mean
concn, μg/kg
Mean recovery,
% s
r
, μg/kg s
R
, μg/kg RSD
r
, % RSD
R
, % HorRat
9
18
Naph
9
18
9
18
8
16
Phe
9
18
9
18
8
16
Pyr
9
18
8
16
9
18
10 g of homogenized sample
- Add
13
C-PAH mixture, vortex, equilibrate (15 min)
Extraction:
- Add 5 mL (or 10 mL) water and 10 mL EtOAc, shake (1 min)
- Add 4 g anh. MgSO4 and 2 g NaCl, shake (1 min), centrifuge
- Evaporate 5 mL aliquot of extract, reconstitute in 1 mL hexane
Silica-SPE clean-up:
-
Condition 1g silica with 6 mL hexane:DCM (3:1,
v/v
) and 4 mL
hexane
-
Apply sample
-
Elute with 10 mL of hexane:DCM (3:1,
v/v
)
GC-MS(/MS) analysis
)LJXUH
$ )ORZ FKDUW RI WKH PHWKRG IRU GHWHUPLQDWLRQ RI
PAHs in seafood using GC/MS.