Spectral laser induced emission measurements in

Spectral laser induced emission measurements in the 200–550 nm range were performed by using as excitation source the fourth harmonic of a Nd-YAG laser at 266 nm. The experimental setup is identical to that used in a previous work [15] and [16]. Some details are reported below. Laser beam – diameter at focal point of 350 μm – was focused in the center of the flame. The emitted Raltegravir at 90° with respect to the laser beam was focused onto the 280 μm entrance slit of a spectrometer and detected by an intensified CCD camera thermoelectrically cooled down to 10 °C to reduce noise. The energy of the laser pulse was kept constant at 0.8 mJ with pulse duration of 8 ns. The chosen laser energy gave the better compromise between laser induced emission signals and species fragmentation interference.
The emission spectra were detected using a gate time of 100 ns synchronized with the laser pulse and by summing the CCD counts over 150 scans. In this way both fluorescence and incandescence signals were detected contemporarily. The measured spectra were corrected for the spectral response of the detection system.