The temporal behavior of the laser enhanced ionization signal of mercury was studied in a quartz cell under low buffer gas pressure. Using fast electronics and a short (34 ns) laser pulse, it was possible to distinguish between the non-selective photoionization component of the signal and that which was due to collisional ionization from selected levels in one time-resolved ionization waveform.

A method for the optical detection of the resonance ionization signal of mercury atoms in a buffer gas is described that is based on the emission from buffer gas atoms that are collisionally excited by interactions with electrons in a strong electric field. The first observations of this phenomenon are reported here, along with comparisons between optical and electrical detection. Advantages of a pulsed electric field over a continuous field are described. A wide range of possible applications for this type of gas phase detector are suggested.

A technique is presented which is based on the measurement of the emission of excited buffer gas atoms which are created by interactions with electrons in a strong pulsed electric field after laser assisted ionization of analyte atoms. In principle, this emission method can be applied for the detection of single atoms, molecules, or photons.

The temporal behavior of the laser enhanced ionization signal of mercury was studied in a quartz cell under low buffer gas pressure. Using fast electronics and a short (34 ns) laser pulse, it was possible to distinguish, in one single time-resolved ionization waveform, the non-selective photoionization component of the signal from that which was due to collisional ionization from selected levels. Experimental results were shown to agree with those obtained by computer simulation, and optimal conditions for deconvolution of the two components were studied.

A system for the electrothermal vaporization flame atomization laser-enhanced ionization (ETV-FL-LEI) detection of Mg was optimized and completely characterized. The vaporization, transport, atomization, probing, and detection efficiencies were all determined experimentally. The overall efficiency of the system was found to be 0.002 51%. The experimental detection limit of 2 ng ml(-1) (20 pg) for Mg was limited by noise due to the blank signal. A detection limit of 590 fg ml(-1) (5.9 fg) could be achieved in the absence of the blank and a reduction of radiofrequency noise.