DETERMINATION OF TRACE AMOUNTS OF SULFIDE IN HUMAN SERUM BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH FLUOROMETRIC DETECTION AFTER DERIVATIZATION WITH 2-AMINO-5-N,N-DIETHYLAMINOTOLUENE AND IRON(III)

A fluorometric high-performance liquid-chromatographic method is descr ibed for the determination of sulfide in human serum. The sulfide ion had been derived into a fluorescent compound with 2-amino-5-N,N-diethy laminotoluene and Fe (III) under an acidic condition. The compound was extracted into 2-octanol as an ion-pair with sodium 1-octane sulfonat e. The extract was separated by a reversed phase method (column, Inert sil ODS-2, 250mm x 4.6mm i.d.;mobile phase, 90% (V/V) acetonitrile aqu eous solution containing sodium 1-octanesulfonate as a counter ion rea gent; flow rate 0.5cm(3).min(-1) and detected fluorometrically (Ex. 64 0nm; Em. 675nm). The sulfide ion could be determined over the range fr om 4.4 x 10(-10)M to 4.4 x 10(-7)M. The coefficient of variation at 4. 4 x 10(-8)M of sulfide was 3.2% (n = 7). The range of concentration of sulfide ion in human serum were from 3.04 x 10(-8)M to 2.24 x 10(-8)M by this method.