AOAC-RI ERP Book - FAOM METHOD.pdf

M ASTOVSKA ET AL .: J OURNAL OF AOAC I NTERNATIONAL V OL . 98, N O . 2, 2015 477

RESIDUES AND TRACE ELEMENTS

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 &RYDQFH /DERUDWRULHV ,QF 1XWULWLRQDO &KHPLVWU\ DQG )RRG 6DIHW\ .LQVPDQ %OYG 0DGLVRQ :, J ANA H AJSLOVA ,QVWLWXWH RI &KHPLFDO 7HFKQRORJ\ )DFXOW\ RI )RRG DQG %LRFKHPLFDO 7HFKQRORJ\ 'HSDUWPHQW RI )RRG &KHPLVWU\ DQG $QDO\VLV 7HFKQLFNi 3UDJXH &]HFK 5HSXEOLF &ROODERUDWRUV - %HW]DQG - %LQNOH\ . %RXVRYD - 0 &RRN / 'UDERYD : +DPPDFN - -DEXVFK . .HLGH 5 /L]DN 3 /RSH] 6DQFKH] 0 0LVXQLV . 0LWWHQGRUI 5 3HUH] 6 3HUH] 6 3XJK - 3XONUDERYD - 5RVPXV - 6FKPLW] ' 6WDSOHV - 6WHSS % 7DIIH - :DQJ 7 :HQ]O

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 WKH PHWKRGV DUH ¿W IRU SXUSRVH DQG DUH FULWLFDO WR JDLQLQJ JOREDO UHFRJQLWLRQ DQG DFFHSWDQFH RI WKH PHWKRGV &RPPHQWV FDQ EH VHQW GLUHFWO\ WR WKH FRUUHVSRQGLQJ DXWKRU RU PHWKRGIHHGEDFN#DRDF RUJ &RUUHVSRQGLQJ DXWKRU¶V H PDLO NDWHULQD PDVWRYVND#FRYDQFH FRP '2, MDRDFLQW PDWUL[HV PXVVHO R\VWHU DQG VKULPS IRUWL¿HG ZLWK VHOHFWHG 3$+ DQDO\WHV DW ¿YH GLIIHUHQW OHYHOV RI benzo[ a ]pyrene (BaP) ranging from 2 to 50 μg/kg. Each matrix had a varying mixture of three different 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 TXDOL¿FDWLRQ SKDVH RI WKH FROODERUDWLYH VWXG\ 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 WKH PHWKRG SURFHGXUH 7HQ ODERUDWRULHV IURP ¿YH FRXQWULHV TXDOL¿HG DQG FRPSOHWHG WKH FROODERUDWLYH study, which was conducted on three seafood

BaP levels. The other studied PAHs were at varying levels from 2 to 250 μg/kg to mimic typical PAH SDWWHUQV 7KH IRUWL¿HG DQDO\WHV LQ WKUHH PDWUL[HV ZHUH 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 DOO WHVWHG DQDO\WHV DW WKH ¿YH GLIIHUHQW FRQFHQWUDWLRQ 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 @DQWKUDFHQH IRUWL¿HG DW 25 μg/kg in oyster (RSD r : 5.84%, RSD R : 21.1%) and lower mean recoveries for anthracene (Ant) and BaP LQ R\VWHU DW DOO WKUHH IRUWL¿FDWLRQ OHYHOV ± 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 WKH PHWKRG LV ¿W IRU SXUSRVH WR GHWHUPLQH 3$+V and their alkyl homologs in seafood samples. The method was approved by the Expert Review Panel RQ 3$+V DV WKH $2$& 2I¿FLDO )LUVW $FWLRQ 0HWKRG 2014.08. A s a response to the 2010 oil spill in the Gulf of Mexico, $2$& ,17(51$7,21$/ IRUPHG WKH 6WDNHKROGHU 3DQHO RQ 6HDIRRG &RQWDPLQDQWV 636& DQG ODWHU issued a call for methods for determination of polycyclic