Analysis of Carbamate and Organophosphate Pesticides in Animal Poisoning Cases by GC/MS
Jessica M Greene, BS Barry Logan, PhD, Stephen Donovan, PhD, Karen Scott, PhD, Alana Balogh, BFA 03/02/17
1 Background
2 Africa
• Pesticides are readily available in Africa for legitimate use • Pesticides are thus available for use as poisons • Conflicts between farmers and wildlife • Poachers attempting to hide illicit activities
3 The Poisonings Effect
• Lions • Vultures • Elephants • Hyenas • Humans
4 Organophosphate & Carbamate Pesticides • Acetylcholinesterase inhibitors • CNS effects can be varied but poisoning ultimately will lead to muscle contractions followed by paralysis and death due to respiratory failure • Absorption occurs through all routes
Figure 1: Organophosphate Figure 2: Carbamate Basic Structure Basic Structure
5 Aims
• Develop and optimize a method for OP and carbamates • Create an extraction procedure for the pesticides • Receive authentic samples • Provide reliable and authoritative results to wildlife advocates in Africa
6 Method Development
7 Original Method
8 Finalization of Method
GC/MS Parameters GC Agilent 7890A Column HP-4MS Ultra Inert Column Length 30 m Carrier Gas Hydrogen Injection Type/Volume Splitless/ 1 µL Inlet Temperature 250 ⁰C Oven Program 40 ⁰C for 1 minute 15 ⁰C/min to 170 ⁰C, hold for 5 minutes 25 ⁰C/min to 350 ⁰C, hold for 3 minutes Flow 1.1 mL/min MS Agilent 5975C MS Scan Range 35-500 amu
9 Test Mix on Final Method
10 Extraction Optimization
11 In-Field Extraction
Add acetone to biological material and mix
Pour mixture through a funnel using a paper towel as a filter
Pour filtrate on clean paper towel and allow to dry
Place dry paper towel in plastic bag and follow shipping procedures
12 In-Field Extraction
13 In-Lab Extraction Method
Place paper towel in tube with 2 mL ethyl acetate, rotate (x2) Decant ethyl acetate
Wash ethyl acetate with deionized water Remove aqueous layer
Wash ethyl acetate with 10% sodium bicarbonate Remove aqueous layer
Wash ethyl acetate with saturated sodium chloride in deionized water Remove aqueous layer
Add ~0.5 g sodium sulfate Decant ethyl acetate
Dry down under nitrogen gas and reconstitute in ethyl acetate
14 Method Validation
15 Limit of Detection
LOD (ng on column) Compounds 1 Aldicarb nitrile, propoxur 10 Methomyl, 3-hydroxycarbofuran, thionazin, sulfotep, phorate, dimethoate, carbofuran, disulfoton, methyl parathion, carbaryl, methiocarb, parathion, famphur 25 Triethyl thiophosphate, oxamyl
16 Recovery
Beta-Naphthol Carbaryl Recovery from In-Field 8.85% 8.48% Extraction Recovery from Lab 73.57% 70.64% Extraction Recovery from Both 6.51% 5.99% Extractions
17 First Stability Study Results 2.5
Malathion Refrigerator (4 2 C)
1.5 Malathion Room
Temperature Peak Peak Area Ratio 1 (25 C)
Malathion 0.5 Oven (40 C)
0 0 5 10 15 20 25 30 35
Days
18 Second Stability Study Results 12
Malathion Fridge (4 C) 10
8 Malathion Room Temp (25 C)
6 Carbaryl Fridge Peak Peak Area Ratio (4 C)
4
Carbaryl Room
2 Temp (25 C)
0 0 5 10 15 20 25 30 Days
19 Authentic Samples
20 Extraction Video
21 Authentic Samples
22 Elephants at Rubbish Dump in Zimbabwe
23 Blank Stomach Extract
Stomach contents from suspected poisoning case
24 Future Work
• Continue receiving samples from Africa for testing • Build a database to track poisoning cases • Developing LC/MS/MS method if more sensitivity is required • Evaluating the stability in the refrigerator (4⁰C) and determine reason for spike
25 Acknowledgements
• Mandi Mohr, Melissa Friscia and Alex Krotulski • Arcadia University Class of 2017 • The Center for Forensic Science Research and Education • Arcadia University
26 References
1. Quinn LP, B, de J, Fernandes-Whaley M, Roos C, Bouwman H, et al. Pesticide Use in South Africa: One of the Largest Importers of Pesticides in Africa [Internet]. In: Pesticides in the Modern World - Pesticides Use and Management. InTech, 2011 [cited 2016 Aug 10]; Available from: http://www.intechopen.com/books/pesticides-in-the- modern-world-pesticides-use-and-management/pesticide-use-in-south-africa-one-of-the-largest-importers-of- pesticides-in-africa 2. Richards N. Carbofuran and Wildlife Poisonings [Internet]. Chichester, UK: John Wiley & Sons, Ltd, 2011 [cited 2016 Aug 10]; Available from: http://doi.wiley.com/10.1002/9781119998532.fmatter 3. Ogada D, Shaw P, Beyers RL, Buij R, Murn C, Thiollay JM, et al. Another Continental Vulture Crisis: Africa’s Vultures Collapsing toward Extinction. 4. Chung SWC, Chan BTP. Validation and use of a fast sample preparation method and liquid chromatography-tandem mass spectrometry in analysis of ultra-trace levels of 98 organophosphorus pesticide and carbamate residues in a total diet study involving diversified food types. J Chromatogr A [Internet] 2010;1217(29):4815–24. Available from: http://dx.doi.org/10.1016/j.chroma.2010.05.043 5. King AM, Aaron CK. Organophosphate and Carbamate Poisoning. Emerg Med Clin North Am [Internet] 2015;33(1):133–51. Available from: http://www.ncbi.nlm.nih.gov/pubmed/25455666 6. Papoutsis I, Mendonis M, Nikolaou P, Athanaselis S, Pistos C, Maravelias C, et al. Development and Validation of a Simple GC-MS Method for the Simultaneous Determination of 11 Anticholinesterase Pesticides in Blood- Clinical and Forensic Toxicology Applications. J Forensic Sci 2012; 7. Luzardo OP, Ruiz-su??rez N, Valer??n PF, Camacho M, Zumbado M, Henr??quez-hern??ndez LA, et al. Methodology for the identification of 117 pesticides commonly involved in the poisoning of wildlife using gc-ms-ms and lc-ms-ms. J Anal Toxicol 2014;38(3):155–63. 8. SEMIVOLATILE ORGANIC COMPOUNDS BY GAS CHROMATOGRAPHY/MASS SPECTROMETRY (GC/MS). 1996; 9. Trehy ML, Yost RA, McCreary JJ. Determination of aldicarb, aldicarb oxime, and aldicarb nitrile in water by gas chromatography/mass spectrometry. Anal Chem [Internet] 1984 [cited 2017 Mar 17];56(8):1281–5. Available from: http://pubs.acs.org/doi/abs/10.1021/ac00272a020
27 Questions? [email protected]
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