Optimization of Chemiluminescent Nitrogen Detection for Packed-Column Supercritical Fluid Chromatography with Methanol-Modified CO_2

摘要

A chemiluminescent nitrogen detector was optimized for packed-column supercritical fluid chromatography. Metha- nol modifier concentrations of 15/100 or less, an ozone flow of 5.8 mL/min, and a decompressed CO_2 flow between 240 and 310 mL/min were found to exhibit a maximum sensitivity of 5 ng for sulfamethazine(1 ng of N). The addition of a membrane drier to the "optimized" system further decreased the minimum detectable quantity(MDQ) to 0.5 ng (0.1 ng of N).