| Popis: |
Elemental sulfur, when used with polystyrene column packings and tetrahydrofuran as solvent, has been found to be an ideal internal standard for precise molecular weights by gel permeation chromato-graphy. Long-term elution time precision of 0.3% has been achieved with less than optimum operation of chromatographic equipment. Sulfur is inert, elutes reproducibily with a symmetrical peak shape and never interferes with the elution of size-separated materials. The internal standard has a high ultraviolet absorption response and a positive differential refractive index. |
