Trace analysis of pollutants in water using the photothermal interferometry as HPLC detector.
A new procedure including high performance liquid chromatography in combination with photothermal interference spectroscopy as detection device (HPLC/PIS) has been proposed, optimized and its figures of merit for pesticide residue analysis are shown. The flowing sample under study is set in one arm of a Mach-Zehnder interferometer, and its refractive index is modulated by a periodically chopped continuous wave argon ion laser. As chopper, an acousto optical modulator has been introduced to switch the excitation laser beam between different lines (457 nm, 488 nm, 514 nm) simultaneously. Thus a multi component analysis can be realized either by using an HPLC-system in front of the PIS device or by a multi line Ar(+)-laser, directly. The limit of detection of the HPLC/PIS system reached 71 microg/l of the pesticide di-nitro-ortho-cresol (DNOC).
Seidel
B S
BS
Institut für Instrumentelle Analytik, Forschungszentrum Karlsruhe, Postfach 3640, D-76021, Karlsruhe, Germany.
Dübel
O
O
Faubel
W
W
Ache
H J
HJ