Robert Clifford (1), Dan Davis (1), Keith Long (1); (1) Shimadzu Scientific Instruments, Columbia, MD, U.S.A.
Hops
Poster
Plants concentrate metals by absorbing them from the soil in which
they are grown. Some metals are beneficial and essential for life,
whereas other metals are highly toxic and have negative effects at even
the lowest levels. Because of their toxicity, quantification of these
elements is needed. This poster will investigate the preparation and
analysis for the heavy metals arsenic (As), cadmium (Cd), lead (Pb), and
mercury (Hg) in Cascade hops using graphite furnace atomic absorption
(GFAA) and cold vapor mercury techniques. Spike and recovery tests are
performed at or below the analysis target levels to ensure the accuracy
and sensitivity of the technique. Pre-dried and ground hops were added
to a closed vessel microwave digest system with nitric acid, hydrogen
peroxide, water and a stabilizer added to ensure the metals remained in
solution for analysis. Samples were analyzed in the low
parts-per-billion (ppb) range.
Robert Clifford received his bachelor’s degree from Glassboro
State College, now Rowan University, in New Jersey, his master’s degree
from Villanova in Pennsylvania, and his Ph.D. degree from George
Washington University in Washington, DC. He has published and presented
over 100 papers in the fields of food, pharmaceutical, environmental,
energy, geology, material science, photonics, and marijuana. However,
his true love is foods and beverages. His first chemistry job was as a
summer intern at the Campbell Soup Company, where he was hired as a
full-time employee. After he went back to graduate school he took
another job as an intern at the FDA, where he was also hired as a
full-time employee. After graduating with his Ph.D. degree he left the
FDA for Shimadzu, where he has worked for the last 25 years. His current
title is marketing manager of food and consumer products.
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