Robert Clifford (1), Laura Chambers (1), William Lipps (1), Nicole Lock (1); (1) Shimadzu Scientific Instruments, Columbia, MD, U.S.A.
Hops
Poster
From a consumer safety point-of-view, quantitation of the pesticide
residues in hops has begun to attract wide interest. There are several
problems associated with analysis of pesticide residues in hops. First
and foremost, there are very few regulatory guidelines established to
define which pesticides to include or what the detection limits should
be. In fact the U.S. government’s 40 CFR Part 180 states individual
tolerances must be established for miscellaneous commodities
intentionally not included in any group including hops. Second, the
matrix is very complex, with significant interferences. Finally, sample
load is growing exponentially, so the chosen method must be quick and
easy to perform. Trace level pesticide analysis in complex food matrices
has been done for many years with similar challenges, thus many of the
analytical protocols emerging for the hops matrix are based on these
well-established techniques. Triple-quadrupole GC-MS/MS operated in MRM
mode provides significant sensitivity and selectivity, but method
development can be expensive and time-consuming. This poster describes a
streamlined method development process for analysis of 34 pesticide
residues in hops using a QuEChERS sample preparation method, followed by
GC-MS/MS detection and quantitation. The pesticides are from five
classes of compounds, including organonitrogen, organophosphorus,
organochlorines, carbamates, and synthetic pyrethroids.
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.
