Analytical procedure for simultaneous use of seven fluorobenzoates in multitracer tests

An analytical procedure allowing simultaneous use of seven fluorobenzoate ( FBA) isomers was developed and examined through column and field tracer exp eriments. The analytical method, based on high performance liquid chromatog raphy (HPLC), included a reverse-phase separation method. This method was f ound to be very efficient for the FBA analysis, allowing accurate determina tion of seven FBAs in a single HPLC run, while avoiding analytical interfer ence of other natural water constituents or pollutants. Consequently, this separation method allo,vs the simultaneous use of seven isomers in multitra cer tests in highly saline or contaminated environments. The mobility prope rties of the FBAs were examined in percolation experiments through a column filled with a mixture of crushed chalk and common fracture filling and coa ting material. The FBAs behaved conservatively as compared to bromid. All s even FBA isomers were successfully used in a multitracer test in a field pe rcolation experiment designed to identify flowpath along a fracture plane.