AOAC-RI ERP Book - FAOM METHOD.pdf

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AOAC RESEARCH INSTITUTE AOAC OFFICIAL METHODS OF ANALYSIS (OMA) OMAMAN-15 : Determination Of Polycyclic Aromatic Hydrocarbons (PAHs) In Seafood Using Gas Chromatography-Mass Spectrometry: A Collaborative Study* Study Director: Katerina Mastovska, Covance Laboratories Inc., Nutritional Chemistry and Food safety, 3301 Kinsman Boulevard, Madison, WI 53704, USA ER 1 PAHs in homogenized seafood’s are extracted with EtOAc:water. Extracts are cleaned with SPE technique before GC-MS analysis. ER 2 This method utilizes solvent extraction of a homogenized sample followed by a silica-SPE procedure. The eluant is introduced into a GC-MS or GC-MS/MS in either SIM or MRM modes. Issues encountered by participating laboratories are typical of PAH analyses including loss of more volatile PAHs during evaporation and background PAH contamination. This method achieved good sensitivity, accuracy and precision and has Limits of detection/quantification that are lower than the levels of concern in seafood samples set by regulatory agencies. ER 3 The method describes analysis of 19 PAHs and alkylated PAHs via GC-MS. Sample preparation involves solvent extraction followed by salting out partitioning with silica SPE cleanup. Method performance criteria are set instead of prescribing specific products/instruments needed to successfully complete analysis. Criteria address analytes recovery, matrix cleanup, calibration quality, chromatographic separation and detector sensitivity. ER 4 This method presented a procedure to determine 19 selected polycyclic aromatic hydrocarbons (PAHs) and their relevant alkyl homologous in seafood using fast sample preparation followed by GC-MS analysis. The sample preparation included two steps: (1) extraction using water-ethyl acetate and salt-out by anhydrous magnesium sulfate and sodium chloride; (2) clean-up by silica gel SPE. GC-MS was very common and practical instrumentation for PAHs analysis. The method is simple, fast, accurate, robust and is easy to follow. ER 5 Collaborative study conducted to determine selected PAHs and relevant alkyl homologues in seafood matrices using a fast sample preparation method followed by analysis with gas chromatography-mass spectrometry (GC-MS). ER 6 This is a GC-MS method with C13 labeled internal standards; sample preparation is a QuEChERS approach followed by SPE cleanup. The method was designed around performance-based criteria regarding the GC separation, SPE, and evaporation steps. ER 7 PAHs in seafood samples (10 g, hydrated with 5 or 10 mL water) are extracted into 10 mL ethyl acetate with the aid of partitioning salts (4 g magnesium sulfate and 2 g sodium chloride). 5 mL of the ethyl acetate extract is concentrated down and cleaned with 1 g silica gel SPE cartridge, the eluate is concentrated and solvent exchanged to 0.5 mL isooctane, and analyzed by GC/MS. ER 8 good Scope of the method includes 19 specific PAHs in seafood. The matrices tested, shrimp, oyster and mussel, are typically 5% lipid content and below (USDA Nutrient database). Lipid content of commodities amendable for this method is an important consideration and should be addressed in the text of the method. Higher fat samples are addressed briefly in the method, indicating that a reduction of volume of extract should be applied to the silica SPE cartridge. This is a reasonable modification to the method but has implications for overall detectability, especially for BaP. It is possible that to meet fat removal criteria, modifications for calibration curves and/or sample preparation will need to be made. Modifications may be significant and therefore some comment on an upper limit of the lipid content applicable for the method as written would be useful. ER 4 The method covers 19 selected PAHs in shrimp, mussel, and oyster with analytical ranges of fit for purpose. The scope should be easily expanded to include more analytes and applied to a verity of seafood or processed ones. ER 5 All Federal, State and Commercial laboratories analyzing PAHs in seafood. ER 6 The methods is intended for seafood that would accumulate PAHs and has been tested using mussel, oyster, and shrimp matrices. ER 7 The method is capable to detect 19 selected PAHs quantitatively in shrimp, oyster and mussel samples. ER 8 good Method Scope/Applicability ER 1 Applicable to seafood’s such as mussel, oyster, and shrimp. ER 2 This method provides determination of PAH and PAH analogues in shrimp, mussels and finfish which are representative of this class of compounds. The method achieves limits of detection well below the regulatory levels of concern. ER 3 Summary of Method