291 / 471
M
astovska
et al
.:
J
ournal of
AOAC I
nternational
V
ol
.
98, N
o
. 2, 2015
477
Received December 16, 2014.
The method was approved by the Expert Review Panel for
Polycyclic Aromatic Hydrocarbons (PAHs) as First Action.
The Expert Review Panel for Polycyclic Aromatic Hydrocarbons
(PAHs) invites method users to provide feedback on the First
Action methods. Feedback from method users will help verify that
the methods are fit for purpose and are critical to gaining global
recognition and acceptance of the methods. Comments can be sent
directly to the corresponding author or
methodfeedback@aoac.org.Corresponding author’s e-mail:
katerina.mastovska@covance.comDOI: 10.5740/jaoacint.15-032
RESIDUES AND TRACE ELEMENTS
A collaborative study was conducted to determine
selected polycyclic aromatic hydrocarbons (PAHs)
and their relevant alkyl homologs in seafood
matrixes using a fast sample preparation method
followed by analysis with GC/MS. The sample
preparation method involves addition of
13
C-PAH
surrogate mixture to homogenized samples and
extraction by shaking with a water–ethyl acetate
mixture. After phase separation induced by addition
of anhydrous magnesium sulfate–sodium chloride
(2 + 1, w/w) and centrifugation, an aliquot of the
ethyl acetate layer is evaporated, reconstituted in
hexane, and cleaned up using silica gel SPE. The
analytes are eluted with hexane–dichloromethane
(3 + 1, v/v
),
the clean extract is carefully evaporated,
reconstituted in isooctane, and analyzed by GC/MS.
To allow for the use of various GC/MS instruments,
GC columns, silica SPE cartridges, and evaporation
techniques and equipment, performance-based
criteria were developed and implemented in the
qualification phase of the collaborative study.
These criteria helped laboratories optimize their
GC/MS, SPE cleanup, and evaporation conditions;
check and eliminate potential PAH contamination
in their reagent blanks; and become familiar with
the method procedure. Ten laboratories from five
countries qualified and completed the collaborative
study, which was conducted on three seafood
matrixes (mussel, oyster, and shrimp) fortified with
19 selected PAH analytes at five different levels of
benzo[
a
]pyrene (BaP) ranging from 2 to 50 µg/kg.
Each matrix had a varying mixture of three different
BaP levels. The other studied PAHs were at varying
levels from 2 to 250 µg/kg to mimic typical PAH
patterns. The fortified analytes in three matrixes were
analyzed as blind duplicates at each level of BaP and
corresponding other PAH levels. In addition, a blank
with no added PAHs for each matrix was analyzed
singly. Eight to 10 valid results were obtained for
the majority of determinations. Mean recoveries of
all tested analytes at the five different concentration
levels were all in the range of 70–120%: 83.8–115%
in shrimp, 77.3–107% in mussel, and 71.6–94.6% in
oyster, except for a slightly lower mean recovery
of 68.6% for benzo[
a
]anthracene fortified at
25 µg/kg in oyster (RSD
r
: 5.84%, RSD
R
: 21.1%) and
lower mean recoveries for anthracene (Ant) and BaP
in oyster at all three fortification levels (50.3–56.5%
and 48.2–49.7%, respectively). The lower mean
recoveries of Ant and BaP were linked to degradation
of these analytes in oyster samples stored at –20°C,
which also resulted in lower reproducibility (RSD
R
values in the range of 44.5–64.7% for Ant and
40.6–43.5% for BaP). However, the repeatability was
good (RSD
r
of 8.78–9.96% for Ant and 6.43–11.9%
for BaP), and the HorRat values were acceptable
(1.56–1.94 for Ant and 1.10–1.45 for BaP). In all other
cases, repeatability, reproducibility, and HorRat
values were as follows: shrimp: RSD
r
1.40–26.9%,
RSD
R
5.41–29.4%, HorRat: 0.22–1.34; mussel: RSD
r
2.52–17.1%, RSD
R
4.19–32.5%, HorRat: 0.17–1.13;
and oyster: RSD
r
3.12–22.7%, RSD
R
8.41–31.8%,
HorRat: 0.34–1.39. The results demonstrate that
the method is fit-for-purpose to determine PAHs
and their alkyl homologs in seafood samples. The
method was approved by the Expert Review Panel
on PAHs as the AOAC Official First Action Method
2014.08.
A
s a response to the 2010 oil spill in the Gulf of Mexico,
AOAC INTERNATIONAL formed the Stakeholder
Panel on Seafood Contaminants (SPSC) and later
issued a call for methods for determination of polycyclic
Determination of Polycyclic Aromatic Hydrocarbons (PAHs)
in Seafood Using Gas Chromatography-Mass Spectrometry:
Collaborative Study
K
aterina
M
astovska
and
W
endy
R. S
orenson
Covance Laboratories Inc., Nutritional Chemistry and Food Safety, 3301 Kinsman Blvd, Madison, WI 53704
J
ana
H
ajslova
Institute of Chemical Technology, Faculty of Food and Biochemical Technology, Department of Food Chemistry and Analysis,
Technická 3, 166 28 Prague 6, Czech Republic
Collaborators: J. Betzand; J. Binkley; K. Bousova; J.M. Cook; L. Drabova; W. Hammack; J. Jabusch; K. Keide; R. Lizak;
P. Lopez-Sanchez; M. Misunis; K. Mittendorf; R. Perez; S. Perez; S. Pugh; J. Pulkrabova; J. Rosmus; J. Schmitz; D. Staples;
J. Stepp; B. Taffe; J. Wang; T, Wenzl
Candidates for 2016 Method of the Year
232