Optosensing Determination of Parts-per-Billion of Metals

✍ Scribed by Nathan Lacy; Gary D. Christian; Jaromir Ruzicka

• Book ID: 102614430
• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 127 KB
• Volume: 62
• Category: Article
• ISSN: 0026-265X
• DOI: 10.1006/mchj.1998.1696

✦ Synopsis

Optosensing has been successfully applied to the parts-per-billion determination of metals as colored complexes using chemistries previously used in solvent extraction methodologies. The methodology is based on the hydrophobic interactions of the metal complexes with nonpolar sorbents such as C-18 and the simultaneous spectrophotometric monitoring of the adsorbed analyte at the wavelength of maximum absorption. Linear ranges are in the parts-per-billion region with typical correlation coefficients of 0.999. Selective adsorption of the complex, and not the ligand, is achieved through proper adjustment of the elutropic strength of the mixed water-methanol solvent system used in the reaction coils. This mixed-solvent system also allows for the formation of complexes in solution when using ligands which are insoluble in water and allows for adsorption of complexes typically only formed in a two-phase solvent system.