Dr. Julie Palkendo

Professor of Environmental Chemistry

Contact Information
Courses Taught
  • CHM100 - General Chemistry I
  • CHM102 - General Chemistry II Lab
  • ENV100 - Intro to Environmental Science
  • ENV220 - Environmental Analysis
  • CHM230 - Analytical Chemistry I Lab
  • CHM370 - Research in Chemistry
  • ENV370 - Research in Environmental Science
  • ENV380 - Senior Seminar in Environmental Science
headshot of Dr. Palkendo with glasses in front of chemistry glassware on shelves
Current Research Projects

Investigating the Effectiveness of Washing Methods to Remove Pesticides on Fruit

Pesticide residues in foods are warned widely to cause negative impacts on human health. With a desire to achieve healthy lifestyles and nutrition, many households are beginning to consume organic fruits, which are well-known to have significantly lower levels of pesticides.  However, this is not possible for all households as certified-organic options remain expensive.  Therefore, a washing method that can be implemented easily in the home on non-organic fruits is an essential solution for the rising demand in consumption of pesticide-free fruits at a reasonable price.

step-by-step procedure of sample preparation protocol called QuEChERS starting with fruit puree, weighing at a balance, adding reagents, shaking the vials, centrifugation and transfer to a small glass vial

In this work, fruits either experience no washing, or two-or-five-minute soaking in either cold tap water, 10 mg/mL baking soda solution, or diluted Clorox (25 mg/L available chlorine) solution. After washing, the QuEChERS (Quick, Effective, Cheap, Easy, Rugged, Safe) extraction is performed and shown on the left.  LC-MS/MS analysis is then used to screen for 10 fungicides and insecticides commonly found in fruits by the USDA Pesticide Data Program.  The chemical data from the LC-MS/MS not only identifies the presence of the pesticides remaining on and in the fruit, but also allows for quantification.

To date, the most effective washing method seems to be highly dependent on the type of fruit, the type of pesticide, and the concentration of pesticide present. 

Huong Tran presenting her research poster at a conference

Huong Tran, freshman Biochemistry major, presents research poster at Middle Atlantic Regional Meeting (MARM) of the American Chemical Society on June 1, 2019 in Baltimore, MD

Developing an Efficient Solid-Phase Extraction and LC-MS/MS Analysis to Study Drugs and Metabolites in Wastewater Effluent

Pharmaceuticals and their metabolites in recent years have become labeled as “newly-emerging contaminants” by the U.S. Environmental Protection Agency.  The contaminants are actually not new at all, but due to the improvements in analytical instrumentation there are now highly sensitive and selective tools for detection.  Current wastewater treatment plants are very capable of removing pathogens, inorganics, and solid materials; however, little is known about if and how a treatment plant’s design impacts the removal of drugs and their metabolites.

settling tank at wastewater treatment facility with concrete walls on right side and scrappers moving across top of water

The very first step of this project is to determine an efficient and effective solid-phase extraction protocol.  In this process, the sample is converted from raw or treated wastewater to "clean" extract that is ready for analysis by LC-MS/MS.  This sample preparation stage is the most time-consuming of all steps in the experiment and has potential for losing the analytes of interest.

Here an Oasis MCX solid phase extraction (SPE) cartridge is shown and was used to remove impurities and concentrate the drug analytes from a 200-mL sample of wastewater.  The extracted solution was further concentrated by drying under nitrogen and reconstituted in 500 µL of 0.1% formic acid for mass spectrometric analysis. 

single solid phase extraction cartridge attached to manifold and above collection tube
top graph shows gradient of mobile phase composition change and bottom graph shows colorful peaks associated with separation of drug mixture

The second phase of the method development is to modify the liquid chromatographic conditions to best separate the mixture of drugs in the least amount of time possible.  This is done by changing the mobile phase composition of the LC component of the LC-MS/MS instrumentation, which is shown in the top graph.  The bottom graph shows separation of the drugs over time with each colored peak representing a different drug in the standard mixture.

Megan O'Neill standing to right of e-Poster in front of windows with fall background

Junior Biochemistry major Megan O'Neill presented her research ePoster at the Eastern Analytical Symposium in Plainsboro, NJ on November 13, 2018

Past projects
Analysis of Particulate Matter from Train Diesel Emissions in the Borough of Kutztown
Are non-target honey bees, Apis mellifera L., exposed to dinotefuran from spotted lanternfly, Lycorma delicatula, trap trees?
Analysis of NH4+ and NO3- in Soil Samples from Field Margins using Visible Spectroscopy
Developing an Accurate, Robust Method for Microwave Digestion of Metals in Soil Core Samples from the Ecoplot, Kutztown, PA
Investigating the Effects of Natural Gas Fracturing on Local Stream Quality in Susquehanna County, PA
Determination of Wear Metals in Used Motor Oil using Flame Atomic Absorption Spectroscopy
Analysis of Lead in PM2.5 Collected from a Beta Attenuation Monitor from the KU Air Monitoring Station