Optimization of the procedure for the determination of polycyclic aromatic hydrocarbons and their derivatives in fish tissue: Estimation of measurements uncertainty.
Three alternative procedures were employed for the isolation of polycyclic aromatic hydrocarbons (PAHs; 15 of 16 US EPA priority pollutants and benzo[e]pyrene), their methyl-derivatives and sulphur analogues from fish tissue: (1) Soxhlet extraction, (2) batch extraction enhanced by sonication, and (3) saponification of the sample followed by re-extraction of analytes into hexane. Soxhlet extraction using hexane-acetone (1:1, v/v) was the most efficient extraction technique, with analyte recoveries in the range 70-108%. Within optimization of the clean-up step, several types of gel permeation chromatography (GPC) systems were tested: two types of polystyrene divinylbenzene copolymer gels (PSDVB), both 'soft' gel type (Bio-Beads S-X3) and 'rigid' gels type (PL gel and Envirogel) in combination with various mobile phases were compared. Bio-Beads S-X3 and mobile phase chloroform were the most appropriate for purifying of crude extracts before the final determinative step. High-performance liquid chromatography with fluorimetric detection (HPLC/FLD) was used for identification and quantification of PAHs in purified fish extracts. The uncertainties of PAHs measurements were estimated by employing two alternative approaches. Both provided similar results: the expanded uncertainties obtained for individual PAHs by the 'top-down' approach were in the range 9-53%, their values resulting from application of the 'bottom-up' approach were in the range 16-52%.
Jánská
M
M
Technická 3, Institute of Chemical Technology, Prague, Czech Republic.
Tomaniová
M
M
Hajslová
J
J
Kocourek
V
V
D000818:Animals; D002274:Carcinogens, Environmental / Q000032:analysis; D002725:Chloroform; D002850:Chromatography, Gel / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005396:Fish Products / Q000032:analysis*; D005506:Food Contamination / Q000032:analysis*; D007202:Indicators and Reagents; D009153:Mutagens / Q000032:analysis; D009676:Noxae / Q000032:analysis*; D010473:Perciformes; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D011137:Polystyrenes; D012997:Solvents; D013010:Sonication
D002274:Carcinogens, Environmental; D007202:Indicators and Reagents; D009153:Mutagens; D009676:Noxae; D011084:Polycyclic Aromatic Hydrocarbons; D011137:Polystyrenes; D012997:Solvents; C432006:divinylbenzene-polystyrene copolymer; D002725:Chloroform; C003771:Amberlite XAD-2 resin