Cyclic aryleneazachalcogenenes : IV. Gas chromatographic properties of polyfluorinated 2,1,3-benzoselenadiazoles

Polysubstitution of hydrogen atoms in 2,1,3-benzoselenadiazoles (piaselenoles), used in the determination of selenium by gas chromatography with electron-capture detection (GC-ECD), by fluorine atoms raises the sensitivity of a 63Ni electron-capture detector to substances by more than an order of magnitude, without reducing their high volatility. The corresponding polyfluorinated 1,2-diaminobenzenes react quantitatively with Se(IV) derivatives in aqueous acidic media and the selenadiazoles formed are effectively extracted with 1 ml of toluene from 500 ml of solution. Thus, polyfluorinated 1,2-diaminobenzenes potentially form a new group of analytical reagents for the GC-ECD determination of selenium.