Detection at the picogram level of bis(cyclopentadienyl)ruthenium by gas chromatography – flame photometry

Ruthenocene — bis(cyclopentadienyl)ruthenium — can be determined with surprisingly high sensitivity and selectivity by gas chromatography – flame photometry. The detector's response relies mainly on an unidentified emission system (RuH?) with major peaks at 484 and 528 nm, while some familiar atomic lines show up as well. Without interference filter, the minimum detectable amount of ruthenocene, at S/N = 2, is approximately 2 pg (or 2 × 10−13 g/s or 1 × 10−15 mol/s), the elemental selectivity ruthenium/carbon 4 × 105, and the linear range 1:4 × 104. These calibration characteristics place ruthenium among the strongest luminescing and best performing species in the flame photometric detector. In fact, under conditions optimized for ruthenocene, ruthenium responds stronger than other FPD-active atoms (Sn, P, Cr, S, B). Fortunately, quenching effects are very weak: for instance, it takes about 1600 ppm (v/v) of methane in the detector to reduce the ruthenocene peak height by 50%.Keywords: ruthenocene, gas chromatography, flame photometric detector, ruthenium hydride.