the microwave-excited emissive detector in gas-phase chromatography-I Some studies with sulphur compounds.
An examination is made of the characteristics of a microwave-excited emissive detector and its potential use in the gas chromatography of sulphur compounds. The column was operated slightly above atmospheric pressure (ca. 105 kN m (2)) and the microwave detector at a convenient reduced pressure (e.g., 13-40 mbar). It is concluded that the most sensitive and specific wavelengths for analytical purposes are not necessarily the same for all the sulphur compounds examined, viz. carbon disulphide, thiophen, thioglycollic acid, dimethylsulphoxide and sulphur dioxide. The spectra obtained for each compound with argon or helium as carrier gas were characterized and only the atomic lines due to sulphur at 190.0 and 191.5 nm, the CS system with a bandhead around 257.6 nm and the C(2) bandhead at 516 nm were shown to be common to the organic compounds (except CS for thioglycollic acid). Carbon disulphide was the most easily fragmented and gave a limit of detection of 0.2 ng of sulphur at 257.6 nm even with the low luminosity monochromator used. Thioglycollic acid was the least easily fragmented compound.
Dagnall
R M
RM
Chemistry Department, Imperial College, London, S.W.7 UK.
Pratt
S J
SJ
West
T S
TS
Deans
D R
DR