Apparatus and method for interfacing capillary electrophoresis and chemiluminescence nitrogen detection for the analysis of nitrogen-containing compounds

We have developed an interface that allows the specific detection of nitrogen-containing compounds by using a chemiluminescence nitrogen detector. The feasibility of using this interface was demonstrated by separating and detecting two nitrogen-containing compounds, p-aminosalicylic acid and l-phenylalanine. Although baseline separation was achieved, the theoretical plates were lower when compared to UV detection (25 000 vs. ∼85 000). A sensitivity of 75 ng (∼500 pmol) per injection was achieved with this system which is adequate for pharmaceutical and biotech applications.