Dr O.K.D.U.P Nishshanka

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Basic Sciences
Faculty of Health Sciences
Senior Lecturer, Grade II
Contact:

Colombo Regional Center, Department of Basic Sciences, Faculty of Health Sciences, OUSL, Nawala

Office: 112881000, Ext: 721

Email: oknis@ou.ac.lk upul320@yahoo.com


I graduated with B.Sc. Special Degree (Hons) in Chemistry from the University of Kelaniya. After working for about two years as a Temporary Assistant Lecturer in the Department Chemistry at the University of Kelaniya, I started my higher studies at Stevens Institute of Technology, NJ, USA. I earned my M.Sc. and Ph.D. degrees in Organic Chemistry/Mass Spectrometry. My research was focused on gas-phase ion fragmentation mechanisms of small organic molecules. Soon after graduation, I joined the U.S. Food and Drug Administration (FDA), Center for Veterinary Medicine in the Division of Residual Chemistry as a Research Chemist (six years). My research was focused on method development and validation to quantify veterinary drug residues/metabolites in animal-derived foods and animal feeds using cutting edge Liquid Chromatography-Mass Spectrometry (LC-MS), in support of veterinary drug approval and surveillance processes. In 2018, I joined The Open University of Sri Lanka as a Senior Lecturer in Chemistry.

Area of Specification:

Organic Chemistry/Analytical Chemistry/Mass Spectrometry/Residual Analysis/Gas-Phase Ion Chemistry

Research Intrests:

Method development and validation to quantify veterinary drug residues in animal-derived foods and animal feeds. Structure elucidation of small organic molecules based on ion fragmentation patterns. Reaction mechanisms. Bio-remediation of agrochemicals

Affiliations:

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Programmes Coordination:

Pharmaceutical Organic Chemistry

Course Coordination:

BSU3340, BSU3341, BSU4340

Awards:
  • Graduate Award for Outstanding Academic Achievement in Department of Chemistry, Chemical Biology, and Biomedical Engineering, Stevens Institute of Technology. Hoboken. NJ, 2014
  • Outstanding Graduate Achievement Award in Department of Chemistry and Chemical Biology and Biomedical Engineering, Stevens Institute of Technology, Hoboken. NJ, 2007
  • Food and Drug Administration (FDA) Group Recognition Award as a member of the Milk Survey Data Audit Team 2014
  • FDA Team Excellence Award as a member of the VETSULIN Reintroduction Team 2014
  • Excellence in Analytical Science as a member of the Detection of Jatropha Plant Residues and Related Phorbol Ester Toxins Group (FDA) 2014
  • FDA Group Recognition Award: As a member of the Jerky Pet Treat Illness Outbreak Team 2014
  • CVM Organizational Citizenship as a member of the Office of Research Social Events Committees (FDA) 2015
  • FDA, CVM Scientific Achievement Awards, Excellence in Laboratory Science, Distillers Grains work group 2017
Researches:
  • Upul Nishshanka, Hiranthi Jayasuriya, Chaitali Chattopadhaya, Philip J Kijak, Pak Sin Chu, Renate Reimschuessel, Andriy Tkachenko, Olgica Ceric, Hemakanthi G De Alwis, Screening for toxic phorbol esters in jerky pet treat products using LC-MS. Journal of Chromatography B, 2016, 1020
  • Upul Nishshanka, Pak-Sin Chu, Eric Evans, Renate Reimschuessel, Nicholas Hasbrouck, Kande Amarasinghe, Hiranthi Jayasuriya,. Tentative structural assignment of a glucuronide metabolite of methyltestosterone in tilapia bile by liquid chromatography / quadrupole-time of flight mass spectrometry. Journal of Agricultural and Food Chemistry, 201563(24)
  • Upul Nishshanka and Athula B.  Attygalle. Low-energy collision-induced fragmentation of negative ions derived from diesters of aliphatic dicarboxylic acids made with hydroxybenzoic acids. Journal of Mass Spectrometry, 2008, 43(11)
  • Athula B. Attygalle, Jason B. Bialecki, Upul Nishshanka, Carl S. Weisbecker and Josef Ruzicka. Loss of benzene to generate an enolate anion by a site-specific double-hydrogen transfer in CID fragmentation O-alkyl ethers of ortho-hydroxybenzoic acids. Journal of Mass Spectrometry, 2008, 43(9)
  • Athula B. Attygalle, Upul Nishshanka, Carl S. Weisbecker. “Meta Elimination,” a Diagnostic Fragmentation in Mass Spectrometry. Journal of the American Society for Mass Spectrometry, 2011, 22(9)
  • Freneil Jariwala, Ryan E. Wood, Upul Nishshanka, Athula B. Attygalle. Formation of the bisulfite anion (HSO3-, m/z 81) upon collision-induced dissociation of anions derived from organic sufonic acids. Journal of Mass Spectrometry201247(4)
  • Kaleb Duelge, Upul Nishshanka, Hemakanthi de Alwis. Development of a liquid chromatography-triple quadrupole mass spectrometry method for antibiotic residues in distillers grains. Journal of Chromatography B, 2017, 1053
  • Upul Nishshanka and Athula B. Attygalle. Gas phase ketenyl anion formation by site-specific double-hydrogen transfer in mass spectrometric fragmentation of arboxyanilides. Journal of Mass Spectrometry (In preparation).
  • Upul Nishshanka and Athula B. Attygalle.  A pronounced “ortho effect” in collision-induced fragmentation of sodium adducts formed from diesters of aliphatic dicarboxylic acids made with hydroxybenzoic acids. Journal of Mass Spectrometry (In preparation).
Publications:

 

SELECTED POSTER PRESENTATIONS

  • Site-specific Double-hydrogen Transfer During CID Fragmentation Of O-Alkyl Ethers of Ortho-hydroxybenzoic Acids, American Society for Mass Spectrometry Annual Conference, 2008 Denver, USA
  • “Meta Effect” in Fragmentation of Gaseous Ions Derived from Substituted Benzene Derivatives, American Society for Mass Spectrometry Annual Conference, 2011 Denver, USA
  • High Resolution Mass spectrometric characterization of toxic Jatropha factors from Jatropha curcas: Possible contaminants in animal feed and non-food grade glycerin, American Society for Mass Spectrometry Annual Conference, 2013 Minneapolis, USA
  • Development of Liquid Chromatography-Mass Spectrometry Method for Toxic Phorbol Esters in Jerky Treat Products, FDA Foods and Veterinary Medicine Science and Research Conference, 2013 White Oak, Silver Spring, USA
  • Isomer-Specific Fragmentation Pathways of Gaseous Anions Derived from Isomeric Hydroxybenzyl Alcohols (HBAs), American Society for Mass Spectrometry Annual Conference, 2014 Baltimore, USA
  • Proof of principle study: Non-targeted differential analysis of drug-spiked dog urine vs. control urine, American Society for Mass Spectrometry Annual Conference, 2014 Baltimore, USA
  • An LC-MS/MS method to detect antibiotic residues in distillers grains at levels of concern for antimicrobial resistance development, FDA Foods and Veterinary Medicine Science and Research Conference, 2016 White Oak, Silver Spring, USA
  • Determination of veterinary drugs in animal feeds by LC/HRMS, FDA Foods and Veterinary Medicine Science and Research Conference, 2016 White Oak, Silver Spring, USA

 

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