EVALUATION OF A LOW-RESOLUTION NEAR-IR MONOCHROMATOR FOR ATOMIC-EMISSION DETECTION IN CAPILLARY GAS-CHROMATOGRAPHY

A single 0.2 m focal length near-IR monochromator providing a 0.8-3.2 mm effective bandpass was evaluated as spectrometer for F-, Cl-, Br-, I-, S-, and P-selective atomic emission detection in capillary gas chromatography. With optimized plasma conditions and careful wavelength selection, interferences from eluting hydrocarbons were almost eliminated for all the elements studied (element-to-carbon selectivities between 1000:1 and 10000:1), For Cl and S, other heteroatoms were found not to cause cross-interferences, F-, Br-, I-, and P-selective detection, however, was complicated by this second type of non-specificity. For these atoms, elemental confirmation was carried out by analyzing the samples also for heteroatoms potentially causing interferences.