Solvent and pH effects on peroxyolxalate chemiluminescence detection for liquid chromatography

✍ Scribed by Robert Weinberger

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 189 KB
• Volume: 314
• Category: Article
• ISSN: 1873-3778
• DOI: 10.1016/s0021-9673(01)97730-1

✦ Synopsis

The role of the mobile phase modifier, mobile phase water content and pH are described with regard to chemiluminescence (CL) intensity and lifetime for a postcolumn peroxyoxalate CL detection system. In non-aqueous mobile phases, the highest intensities and shortest lifetimes are observed with methanol as a modifier. In more aqueous solvents, the highest intensities are found with acetonitrile or isopropanol. A theory concerning solvent cage effects on the chemical excitor precursor is proposed to account for these observations. However, the role of pH is more significant than the selection of the mobile phase modifier. The optimum pH for peroxyoxalate CL with bis-(2,4,6-trichlorophenyl)oxalate as the chemical excitor is approximately 7.5. By properly buffering both the organic and aqueous solvents, gradient elution with CL detection is highly practical.