Molar Masses and Radii of Humic Substances Measured by Light Scattering

✍ Scribed by Wagoner, D. B. ;Christman, R. F.

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 272 KB
• Volume: 26
• Category: Article
• ISSN: 0323-4320
• DOI: 10.1002/(sici)1521-401x(199805)26:3<191::aid-aheh191>3.0.co;2-1

✦ Synopsis

A bulk aquatic natural organic material (NOM) was characterized by high-performance size exclusion chromatography (HPSEC) coupled with multi-angle laser light scattering (MALLS), UV-Vis, and refractive index detection. This technique was used to measure the molar mass and radius of the natural organic matter in solution. Results indicate that the NOM aggregates to a large extent at the concentrations used in this study (5...15 mg mL -1 ). The solution conditions of pH and ionic strength were also shown to affect the measured size of NOM. The number and type of HPSEC columns also influenced these measurements. The importance of using multiple detectors was illustrated by peaks that were not detected by all the detectors. While these data are preliminary and have large errors associated with them, it is nevertheless an indication that HPSEC-MALLS can be used to investigate the effects of solution conditions and aggregation on the size of humic substances in solution.