Separation of fuchsin homologs using high performance liquid chromatography.

Commercial samples of basic fuchsin contain variable proportions of four homologs, pararosaniline, rosaniline, magenta II, and new fuchsin. That different samples of dyes give variable staining is documented in the literature. Three commercial samples of basic fuchsin were investigated using high performance liquid chromatography. Separation of homologs was achieved using a C18 adsorbant and a solvent system of methanol:water:glacial acetic acid (66:24:10).

Thin layer chromatography of commercial samples of amido black 10B.

The tannic acid-phosphomolybdic acid-amido black (TPA) stain has been used primarily for staining hemoglobin. That different dye lots of amido black cause variable staining is documented in the literature. Nine commercial samples of amido black were investigated using thin layer chromatography; all of these dyes contained colored contaminants. Separation of contaminants was achieved using silica gel thin layer chromatography and a solvent system of 95% ethanol:90% phenol:concentrated NH4OH, 12:9:3. TPA staining of red blood cells was improved by using purified amido black.