Analysis of all pesticide residues in cannabis regulated by California and Oregon state using LC/MS/MS with Electrospray and APCI source

Transcription

1 Analysis of all pesticide residues in cannabis regulated by California and Oregon state using LC/MS/MS with Electrospray and APCI source Avinash Dalmia July 10 th 2018 NACRW 2018 PerkinElmer

2 Challenges for Cannabis Pesticide Analysis with LC-MS/MS Complex Chemistry and Matrix Interferences Lists Include Pesticides with low Ionization efficiency List Includes GC-MS/MS amenable pesticides including very hydrophobic and organochlorine pesticides No Standardized Methods for LC-MS/MS No Sample preparation Guidelines Dirty matrix contaminates Instrument Ion Source Action limits are continually being lowered

3 Review: California Versus Oregon State Action Limits Analyte OR Action Limits/ppm CA Action Limits/ppm Ratio of OR to CA Action Limits Abamectin Acephate Acequinocyl Fipronil Naled PCNB NA 0.1 NA Propiconazole Aldicarb Chlordane NA 0.1 NA Chlorfenapyr Daminozide California action limits are lower than Oregon State Limits by a factor of 4-20

4 Step Number One: Determine Optimum Ion Source Conditions and MRM Transitions for Analytes with Low Signal (MRM = Multiple Reaction Monitoring)

5 Abamectin Signal Abamectin is Sensitive to Heat in Ion Source 5.00E E E E E E E E E E E Source Temperature/oC 100ppb Abamectin MRM Qualifier 100ppb Abamectin MRM Quantifier S/N=41 S/N=67 (LOQ=25 ppb 4 fold lower than CA action limits) The sensitivity was improved for abamectin by a factor of 10X

6 Signal and Sensitivity Improvement for 100 ppb Dibrom in Cannabis (LOQ = 10 ppb ) 10 fold lower than CA Action Limits Conventional MRM DiBrom MRM Optimized MRM DiBrom Quantifier S= 5.46e3 S/N= 96 S= 1.44e4 S/N= 255 DiBrom MRM S= 1.6e3 S/N= 20 DiBrom Qualifier S= 1.38e4 S/N= 240

7 Step Number Two: Find MRM Transitions with Less Matrix Interference (MRM = Multiple Reaction Monitoring)

8 100 ppb Acequinocyl in Cannabis (LOQ=25 ppb) Improved by a Factor of 20) Conventional MRM Transitions Matrix Interference Optimized MRM Transitions NO Matrix Interference Green trace is signal for 100 ppb acequinocyl in cannabis; Red Trace is signal in cannabis blank

9 Pyrethrins

10 Cinerin II MRM Signal Cinerin II MRM Signals in Solvent & Blank Cannabis Extract 9.E+04 8.E+04 7.E+04 6.E+04 5.E+04 4.E+04 3.E+04 2.E+04 1.E ppb Cinerin II Signal in Solvent Cinerin II Transition Signal in Blank Cannabis Extract 0.E Unique Cinerin II MRM Transition

11 Step Number Three: Develop a Sensitive APCI Method for Highly Chlorinated and Non-Polar Pesticides

12 Pentachloronitrobenzene (PCNB) Structure C6Cl5NO2 Does not form adducts and cannot gain or lose a proton therefore cannot be ionized with electrospray It is traditionally analyzed by GC/MS with EI source.

13 100 ppb PCNB in Cannabis (LOQ = 10 ppb which is 10 times lower than CA action limits) Pentachloronitrobenzene MRM qualifier Pentachloronitrobenzene MRM quantifier S/N=330 S/N=360 Blank MRM Blank MRM

14 QSight LOQ and Action Limits for Selected Pesticides in Cannabis Analyte OR Action Limits, ppm CA Action Limits, ppm QSight 200 LOQ, ppm Ratio of Action limits to QSight LOQ Abamectin Acephate Acequinocyl Fipronil Naled PCNB NA Propiconazole Aldicarb Chlordane NA Chlorfenapyr Daminozide QSight LOQ is lower than California and Oregon State action limits

15 Step Number Four: Method Robustness Evaluation

16 100 ppb Dimethoate Peak Area Ratio to Internal standard in Cannabis Extract 100 ppb Dimethoate Peak Area Ratio to Internal standard in Cannabis Extract One Week Long Term Stability Data for Dimethoate in Cannabis Extract 5.E+05 5.E+05 4.E+05 4.E+05 3.E+05 3.E+05 2.E+05 2.E+05 1.E+05 5.E+04 0.E No Internal Standard RSD = 5.74 % Run Number Internal Standard RSD =1.9 % Run Number

17 Step Number Five: Optimized Sample Preparation Method

18 Cannabis Extracts with Solvent Extraction Sample prep is a huge pain point in labs QuEChERs not needed QuEChERS Complex-multiple steps Low recoveries for polar compounds (daminozide) Solvent Extraction Simple Good recoveries for all compounds Extracted ACN Solution Low recoveries for ph and heat sensitive compounds Good recoveries for all compounds

19 Pesticide Recovery Data with Acetonitrile Extraction Method S.No. Category II Residual Pesticide Low Level 0.1 ppm High Level 1 ppm RSD, % (n=5) Recovery, % RSD, % (n=5) Recovery, % 1 Abamectin Acephate Acequinocyl Azoxystrobin Bifenazate Boscalid Chlorantraniliprole Cypermethrin Daminozide Fenhexamid Fludioxonil Naled Oxamyl Pentachloronitrobenzene Permethrin Propiconazole Pyridaben Spinosad Spirotetramat Spiroxamine Log (Kow) = -1.5 for Daminozide

20 Plug-In Ready Cannabis Pesticide SOP Sample Prep Details Instrument, Standards and Consumable Requirements Instrument Setup Instrument Method/Calibration Internal Standard Selection Reporting Templates Training & App Support Patent Pending

21 A Flow Based LC-MS/MS (patented) Qsight LC-MS/MS System Flow Based MS uses StayClean Technology Inlet stays clean for long time Significantly reduces downtime Easier optimization Unique dual source ESI, APCI (some pesticides best done by one or the other) Identical performance from either source Vertical design Limited space in many smaller labs

22 LC-MS/MS method that meets all action limits required for pesticides in cannabis Method quantitates both GCMS and LCMS amenable pesticides with dual ESI/APCI source Robust and stable APCI/ESI method with minimal prep and cleanup required Recovery in the range of % One instrument Solution for pesticides analysis in cannabis flower extract

23 Acknowledgements: Molly Murphy Travis Ruthenberg 23 Ben Armstrong Erasmus Cudjoe Jacob Jalali Feng Qin Charlie Schmidt

24 Thank You for Your Interest