Fast sequential injection determination of benzo[A]pyrene using variable angle fluorescence with on-line solid-phase extraction

A methodology for the analysis of drinking water for one of the most potent carcinogenic agents known; benzo[a]pyrene (BaP), in the presence of other interfering PAHs is presented. The methodology described is based on the se quential injection analysis of the sample on to a microcolumn (containing 5 mg of C-18) where extraction and preconcentration of BaP takes place, foll owed by elution of BaP with 1 ml of 1,4-dioxane and subsequent detection by using variable angle fluorescence. The advantages of the method include th e small amount of stationary phase employed together with the possibility o f re-using the phase in order to carry out a large number of injections wit hout the need for column re-packing. Also noteworthy is the small volume of 1,4-dioxane used to elute the BaP retained on the column and the small sam ple volumes required (9-10 ml) for achieving detection limits at the ng 1(- 1) level. Thus, a methodology for BaP determination is obtained which compl ies with the requirements of the 98/83/EC Directive which fixes a maximum a dmissible concentration for this pollutant in waters for public consumption of 10 ng 1(-1). The variable angle spectra obtained are further processed by means of the multiple linear regression technique. The detection limit f or BaP is 2.5 ng 1(-1), and the linear range is between 7.5 and 280 ng 1(-1 ).