High performance liquid chromatography-chemiluminescent nitrogen detection: HPLC-CLND

Abstract

Publisher Summary Although the detection mechanism is the same for elemental total nitrogen analyzer and GC-CLND, HPLC-CLND was developed for handling HPLC mobile phases and subsequent nitrogen detection. Schematic flow diagram for HPLC-CLND and photograph of the detector are shown in this chapter. Configurations of the dual HPLC-CLND and UV detection with a 4.6 mm I.D. analytical column are also shown in the chapter. In the former configuration, the HPLC-CLND and fraction collection are accomplished post-UV detection. In this case, a high pressure UV cell is recommended. Three types of splitters have been used: Y-splitter (Valco), T-splitter (Keystone Scientific), and capillary GC splitter (SGE). All three splitters worked well. Most significant reason for using HPLC-CLND is that amines (primary, secondary, and tertiary, as well as quaternary ammonium) attached to compound which do not contain UV chromophore(s) are difficult to detect by conventional UV detectors. On the other hand, CLND can readily detect amines and other nitrogen containing compounds. In this chapter, high performance liquid chromatography, chemiluminescent nitrogen detector (HPLC-CLND) is demonstrated, as a tool that can provide the means to facilitate an analytical method development process. Reversed phase HPLC-CLND technique is presented where ethylene thiourea (ETU) standard is fortified in apple juice and recoveries are analyzed after sample clean-up. Since sample preparation is also a very important part of the most analytical processes, a relatively new solid phase extraction method using the SPEC-Microcolumn technology is demonstrated. Microcolumn is a solid phase extraction disc having more surface area than particles that are used in most solid phase extractions (SPE).