Modified laser light-scattering detector for use in high temperature micro liquid chromatography

Abstract

Non-aqueous high temperature micro liquid chromatography with packed capillary columns has been utilized for the investigation of a modified laser light scattering detector. The original nebulizer in a laser light scattering detector, which was not capable of operating at volumetric flow-rates of less than 10 μl/min, was replaced with a capillary nebulizer that was placed at a drift tube distance of 7 cm, measured from the end of the drift tube. This distance combined with an external gas heating device, gave a `clean' signal without fluctuations and with acceptable baseline noise. The limit of detection was less than 3 ng ( S/ N=3), and a linear direct calibration curve ( R 2=0.9999) was obtained between 50 and 500 ng for two antioxidants injected on a packed capillary column ( n=3). Retention control by temperature programming was allowed at a ramp rate of less than 5–6°C/min. Fatty amides and acyl glycerol were chromatographed by temperature programming.