37 / 311
© 2015 AOAC INTERNATIONAL
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/
hexane.
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 GHSHQGHQW RQ
the silica deactivation,
see Note 4
EHORZ &ROOHFW WKH HOXHQW
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
volume to avoid sample breakthrough during the cleanup step.
2
(WK\O DFHWDWH VKRXOG QRW EH SUHVHQW LQ WKH H[WUDFW DSSOLHG
to the silica cartridge because it can affect the extract polarity,
thus potentially retention of fat and analytes on the silica gel. The
FRH[WUDFWHG IDW DQG / LVRRFWDQH DFW DV NHHSHUV GXULQJ WKH ¿UVW
HYDSRUDWLRQ VWHS VWHS
8
WKXV WKH HYDSRUDWLRQ VKRXOG EH FRQGXFWHG
JHQWO\ XQWLO WKHUH LV QR VLJQL¿FDQW FKDQJH LQ WKH YROXPH L H XQWLO
only the isooctane and coextracted fat are left in the evaporation
WXEH RU ÀDVN
3
$GGLWLRQ RI ± P/ HWK\O DFHWDWH WR WKH HOXHQW LQ VWHS
13
is
recommended for a better control of the evaporation process and
higher absolute recoveries of volatile PAHs.
4
7KH GHDFWLYDWLRQ DQG VWRUDJH RI VLOLFD JHO 63( FDUWULGJHV
can vary, potentially resulting in different amounts of water in
the silica, thus its potentially different retention characteristics.
7KHUHIRUH LW LV LPSRUWDQW WR WHVW WKH HOXWLRQ SUR¿OHV RI 3$+V DQG
fat and determine the optimum volume of the elution solvent to
ensure adequate analyte recoveries and fat cleanup. The following
procedure is recommended:
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
FROOHFWLQJ P/ HOXWLRQ IUDFWLRQV LQ HYDSRUDWLRQ WXEHV RU ÀDVNV
$GG P/ LVRRFWDQH WR HDFK HOXWLRQ IUDFWLRQ DQG HYDSRUDWH GRZQ
WR P/ XVLQJ WKH RSWLPL]HG HYDSRUDWLRQ FRQGLWLRQV $QDO\]H
HDFK IUDFWLRQ E\ *& 06
c
'HWHUPLQH 3$+ HOXWLRQ SUR¿OH E\ SORWWLQJ DQDO\WH UHVSRQVH
SHDN DUHD RU KHLJKW LQ D JLYHQ IUDFWLRQ QRUPDOL]HG WR WKH VXP
of analyte responses in all tested fractions vs the elution volume.
See
Figure
2014.08B
IRU DQ H[DPSOH RI D 3$+ HOXWLRQ SUR¿OH ,W LV
UHFRPPHQGHG WR DGG DQ DGGLWLRQDO
P/ RQ WRS RI WKH GHWHUPLQHG
HOXWLRQ IUDFWLRQ FRUUHVSRQGLQJ WR
UHFRYHU\ DV D VDIHW\
margin ensuring good analyte recoveries in routine practice. This
ZRXOG UHVXOW LQ WKH RSWLPXP HOXWLRQ YROXPH RI P/ IRU WKH VLOLFD
cartridge tested in Figure
2014.08B
.
d
7R FKHFN WKH HIIHFWLYHQHVV RI IDW UHPRYDO GLVVROYH PJ
SXUH ¿VK RLO RU DQ\ VXLWDEOH IDW LQ P/ KH[DQH DQG DSSO\ LW
RQWR WKH VLOLFD JHO FDUWULGJH ZKLFK ZDV FRQGLWLRQHG ZLWK P/
KH[DQH±GLFKORURPHWKDQH
Y Y DQG P/ KH[DQH (OXWH ZLWK
WKH RSWLPXP HOXWLRQ YROXPH RI KH[DQH±GLFKORURPHWKDQH
Y Y ZKLFK ZDV GHWHUPLQHG LQ WKH SUHYLRXV VWHS H J P/
for the example in Figure
2014.08B
&ROOHFW WKLV IUDFWLRQ LQ DQ
HYDSRUDWLRQ WXEH RU ÀDVN ZKLFK HPSW\ ZHLJKW DIWHU KHDWLQJ LQ
DQ RYHQ WR UHPRYH PRLVWXUH ZDV UHFRUGHG WR IRXU GHFLPDO SODFHV
7DEOH
'
continued
PAH
No. of
laboratories No. of replicates
Mean
concn, μg/kg
Mean recovery,
%
s
r
, μg/kg s
R
, μg/kg RSD
r
, % RSD
R
, % HorRat
9
18
20.0
80.1
1.0
2.2
4.8
10.7
0.37
Naph
9
18
71.0
88.7
5.3
9.4
7.5
13.2
0.55
9
18
106.2
84.9
7.3
14.7
6.9
13.9
0.62
8
16
193.9
86.2
6.0
29.8
3.1
15.4
0.75
Phe
9
18
41.6
83.2
3.0
5.5
7.2
13.2
0.51
9
18
80.3
80.3
6.1
10.7
7.6
13.3
0.57
8
16
203.9
81.6
9.5
22.5
4.7
11.0
0.54
Pyr
9
18
34.0
85.1
2.2
3.3
6.4
9.8
0.37
8
16
63.2
84.3
2.2
5.3
3.5
8.4
0.35
9
18
163.4
81.7
8.0
16.6
4.9
10.2
0.48
J RI KRPRJHQL]HG VDPSOH
$GG C 3$+ PL[WXUH YRUWH[ HTXLOLEUDWH PLQ
([WUDFWLRQ
$GG P/ RU P/ ZDWHU DQG P/ (W2$F VKDNH PLQ
$GG J DQK 0J62 DQG J 1D&O VKDNH PLQ FHQWULIXJH
(YDSRUDWH P/ DOLTXRW RI H[WUDFW UHFRQVWLWXWH LQ P/ KH[DQH
6LOLFD 63( FOHDQ XS
-
&RQGLWLRQ J VLOLFD ZLWK P/ KH[DQH '&0
v/v
DQG P/
KH[DQH
-
$SSO\ VDPSOH
-
(OXWH ZLWK P/ RI KH[DQH '&0
v/v
GC 06 06 DQDO\VLV
)LJXUH
$ )ORZ FKDUW RI WKH PHWKRG IRU
GHWHUPLQDWLRQ RI 3$+V LQ VHDIRRG XVLQJ *& 06