EVALUATION OF LIQUID-LIQUID-EXTRACTION AND LIQUID-SOLID EXTRACTION WITH A NEW SORBENT FOR THE DETERMINATION OF POLYCYCLIC AROMATIC-HYDROCARBONS IN RAW AND FINISHED DRINKING WATERS

A comparative study has been made of the application of the liquid-sol id extraction (LSE) technique using a new sorbent solid, tC18, and liq uid-liquid extraction (EPA Method 610) of 11 polycyclic aromatic hydro carbons (PAHs) considered by the EPA as priority pollutants. The exper imental conditions of both extraction techniques are evaluated and app lied to the determination of 11 PAHs using a simple HPL chromatograph with fluorometric detection. The recovery yields obtained were greater in LLE. However, for most of the PAHs the yields were found to be gre ater than 80% with LSE. The detection limits do not differ significant ly between either technique and vary between 0.007 mu g . L(-1) (benzo [k]fluoranthene) and 1.3 mu g . L(-1) (naphthalene). The absolute stan dard deviations and variation coefficients of both techniques are slig htly higher with LSE and vary between 0.007 and 0.37 mu g L(-1) and be tween 8 and 19%, respectively. The method was applied to analyze raw a nd finished drinking waters from four towns supplied with different wa ter sources and qualities.