Liquid chromatography with fluorescence detection of lasalocid sodium in feeds and premixes.

Lasalocid sodium is extracted directly from feeds and premixes with the mobile phase solution, an aliquot is chromatographed, and the concentration (peak height) of lasalocid sodium is measured by high pressure liquid chromatography with fluorescence detection. Chromatography and detection are completed in about 7 min. The results agree well with those found by the official AOAC fluorometric method, 42.

High pressure liquid chromatographic separation and identification of vitamins D2 and D3 in the presence of fat-soluble vitamins in dosage forms.

A simple and rapid qualitative method is described for determining the presence of vitamin D2 (ergocalciferol) and/or vitamin D3 (cholecalciferol) in various preparations by reverse phase high pressure liquid chromatography (HPLC). When both D2 and D3 are present, this method effectively separates and identifies each vitamin D form by its respective retention time. A significant difference between vitamins D2 and D3 exists in their antirachitic activity in poultry.

Collaborative study of a spectrofluorometric method for lasalocid sodium in feeds.

A collaborative study has been completed on a spectrofluorometric method for determining lasalocid sodium in finished poultry feeds. After a brief treatment of feed samples with pH 4.7 buffer, the drug is extracted with ethyl acetate.