SYNCHRONOUS SCANNING 2ND DERIVATIVE SPECTROFLUOROMETRY FOR THE SIMULTANEOUS DETERMINATION OF DIFLUNISAL AND SALICYLIC-ACID ADDED TO SERUM AND URINE AS TERNARY COMPLEXES WITH TERBIUM AND EDTA

By using second derivative synchronous scanning fluorescence spectrome try the simple resolution of two nonsteroidal, antiinflammatory drugs diflunisal and salicylic acid, as ternary complexes with terbium and E DTA, is accomplished. The method developed is simple, sensitive and ra pid, and has been successfully applied for the determination of both c ompounds in 10 mu l of untreated human serum and urine samples. The de tection limits for diflunisal were 0.9 and 1.8 mg l(-1), and for salic ylic acid 1.2 and 1.7 mg l(-1), in serum and urine, respectively. The mean analytical recoveries from serum and urine samples spiked with di flunisal (25-100 mg l(-1)) and salicylic acid (28-138 mg l(-1)) were 9 9 +/- 8% (serum) and 102 +/- 8% (urine) for diflunisal and 102 +/- 9% (serum) and 95 +/- 8% (urine) for salicylic acid. The precision of all determinations varied from 2.5 to 10%.