NEAR-INFRARED LASER-INDUCED FLUORESCENCE DETECTION IN COLUMN LIQUID-CHROMATOGRAPHY - A COMPARISON OF VARIOUS LASERS AND DETECTION SYSTEMS .2. PULSED LASERS
Ajg. Mank et al., NEAR-INFRARED LASER-INDUCED FLUORESCENCE DETECTION IN COLUMN LIQUID-CHROMATOGRAPHY - A COMPARISON OF VARIOUS LASERS AND DETECTION SYSTEMS .2. PULSED LASERS, Journal of chromatography, 695(2), 1995, pp. 175-183
The applicability of two pulsed lasers, a XeCl-excimer/dye laser and a
Nd:YAG/dye laser combination, as excitation sources for near-infrared
(NIR) laser-induced; fluorescence (LIF) detection in column liquid ch
romatography (LC) is studied. Using gradient LC, the best detection li
mit for the model compound, disulphonated aluminum phthalocyanine (AlP
cS2), is 4 . 10(-12) M obtained using the excimer/dye laser combinatio
n. This value is about 10-fold lower than obtained with the Nd:YAG las
er, but 20-fold higher than for CW diode laser excitation, as reported
in Part I of this study [J. Chromatogr. A, 695 (1995) 175]. Because o
f excitation saturation the optimum results were obtained using only a
fraction of the available power. A detailed theoretical discussion is
presented which underlines the experimental results and provides insi
ght into the factors that determine the detection limits.