Edwards, T; Merilees, HL; Mcbride, BC
PESTAB. A simple, rapid, one-step procedure for identifying arsenic compounds in complex biological systems has been developed. Samples of distilled water or domestic sewage sludge containing sodium arsenate, sodium arsenite, sodium methyl arsonate, or sodium cacodylate were prepared. The samples were centrifuged and the supernatants analyzed by electrophoresis on nonfluorescent cellulose thin-layer chromatographic sheets. At pH 7.0, arsenate, methylarsonate, and cacodylate migrated to the anode; arsenite moved to the cathode. Assigning arsenate a mobility of 1.0, methylarsonate and cacodylate had relative mobilities of 0.86 and 0.47, respectively. In addition, methylarsonate appeared as a light blue spot, while arsenate was dark blue. Sodium tellurate, sodium nitrate, sodium nitrate, sodium sulfite, and sodium sulfate did not interfere with migration or form colored complexes with the developing reagents. Sodium phosphate appeared as a blue spot with a relative mobility of 0.84. Large quantities of contaminating salt, protein, lipid, and carbohydrate had no adverse effects on the system.