With regard to the elution step, to ensure high recoveries of
all PAH metabolites, mixtures of solvents are usually
recommended.21 Different solvents and volumes were
evaluated, and it was found that the presence of methanol
was important; nonetheless, neither methanol nor dichloromethane,
alone, eluted efficiently 1-hydroxynaphthalene (recoveries
of 15 and 40%, respectively) and 1-hydroxypyrene
(recoveries of 32 and 8%, respectively). In agreement with
other authors,17 10 mL of methanol/ethyl acetate was the best
approach to obtain greater recovery.
Method Validation. The developed analytical method
complied with criteria for the performance characteristics as
established by Commission Decision 2002/657/EC.38