Contributions of walter A. Pons, to development of methodology for mycotoxins

Walter Pons began work on mycotoxins in 1963, well prepared by 20 years’ experience in the Analytical Section of the SURDD, USDA. His first paper on aflatoxin methodology, presented at the fall meeting of the AOCS in 1964, was rated as one of the 3 best. In this paper, he introduced acetone as the extraction solvent for aflatoxins, moved away from the lengthy, exhaustive Soxhlet extraction to the far more rapid equilibrium shaker extraction and introduced lead acetate to precipitate major interfering impurities. He early saw the need for the calibration of reference aflatoxin standards and for their availability. He prepared and supplied more than 3,000 aflatoxin standards, used worldwide, as a public service of USDA before such standards were available commercially. Walter Pons pioneered in every aspect of development of analytical methodology for aflatoxins. He was instrumental in development of objective densitometric methods for determination of aflatoxins in diverse commodities, including milk, eggs and mixed feeds; in multimycotoxin methodology; in application of minicolumns for the rapid estimation of aflatoxins in various agricultural commodities; and, most recently, in application of high pressure liquid chromatography to the precise objective determination of aflatoxins. Many of Walter’s contributions resulted from the generous gift of his time. He organized symposia, presented seminars, participated in workshops and responded freely and enthusiastically to numerous requests from analysts for assistance.