Analytical Challenges and Solutions in Trace Analysis Facing Food Safety Laboratories

Transcription

1 Analytical Challenges and Solutions in Trace Analysis Facing Food Safety Laboratories Catherine Rawlinson 1,2,3, Bruce Peebles 1,2,4, Sarah Hayton 2,4, Maria Wenner 2,4, Joel Gummer 1,2,3, Garth Maker 1,2,3,4, Ian Mullaney 2,4, Robert Trengove 1,2,3,4 Murdoch University, Perth, Western Australia 1 Advanced Mass Spectrometry Facility; 2 Separation Science & Metabolomics Laboratory; 3 Metabolomics Australia; 4 School of Veterinary and Life Sciences r.trengove@murdoch.edu.au NATA Accredited Laboratory ISO/IEC Accreditation Number: Trengove, Advances in Food Safety Analysis eseminar

2 The Challenges for Trace Analysis From a consumer perspective Consumers have a strong demand for residue free food Organic Produce? Grains have gone from being just a commodity to being a food

3 The Challenges for Trace Analysis From a consumer perspective Consumers have a strong demand for residue free food Organic Produce? Grains have gone from being just a commodity to being a food Consumers want to associate residue ingestion via food and exposure with health This follows from developments in genetics and personalised medicine The Exposome concept/vitaeomics

4 The Challenges for Trace Analysis Pressure to phase out many compounds that have been in use for a long time and for which the toxicology data is old and based on a series of individual tests We now have the capability to look at the potential toxicology implications of exposure in model systems to study the range of acute short term exposure to chronic long term exposure With these model systems we can also differentiate between total chemical exposure and actual chemical levels metabolised

5 B50 cell line rat neuroblastoma, + Permethrin 6 h 24 h 48 h + 200μg/mL Permethrin

6 B50 cells + Malathion 6 h 24 h 48 h + 200μg/mL Malathion

7 The Challenges From an analytical perspective We now have the capability to measure even more chemical residues, faster We can measure the residues at even lower levels and with high resolution & accurate mass We can use a targeted approach or an untargeted approach with automated MS/MS

8 The Challenges From an analytical perspective We now have the capability to measure even more chemical residues, faster We can measure the residues at even lower levels and with accurate mass We can use a targeted approach or an untargeted approach with automated MS/MS QTOF technology has been a major driver However, this capability comes at a price premium

9 The Challenges of regulatory MRLs in terms the public resonates with Consider an Olympic pool Based on a nominal depth of 2 metres the volume of water is 2,500,000 Litres This equates to 2,500,000 kilograms (kg) of water 1 part per million (ppm) equates to 2.5 kg in an Olympic swimming pool (2.5 litres of liquid) 1 part per billion (ppb) equates to 2.5 grams in an Olympic swimming pool (2.5 ml of liquid) Japanese List MRL 10 ppb for many compounds

10 The Challenges of regulatory MRLs in terms of what modern instruments can achieve Consider an Olympic pool 100 parts per trillion (100 ppt) equates to 0.25 grams in an Olympic swimming pool (0.25 ml of liquid) 1 part per trillion (1 ppt) equates with grams (or 2.5 mg) in an Olympic swimming pool A grain in an Olympic swimming pool ( ml or 2.5 ul of liquid) There is zero tolerance for some compounds (banned) The lower the LOD of instruments the closer we get to a zero tolerance

11 Instrumental capability in context

12 The Challenges of regulatory MRLs in terms of what modern instruments can achieve The practical implications Farmers and Growers need to know that if the residues are there they will be detected Farmers and Growers need to fully understand: the with-hold periods the half-lives of the chemicals in the commodities of interest

13 A key component of the solution High throughput sample analysis QuEChERS has helped enormously We are now seeing modifications to deal with incurred samples

14 We are in the TOF era? Accurate Mass, High Resolution Data, High Data Density However, this capability comes at a price premium High throughput analysis is becoming a reality

15 The Solutions FTMS instruments are also now scanning faster and are part of the higher throughput solution

16 QTOFs - MS & MS/MS Simultaneous Full Scan & MS/MS Data dependent MS/MS MS E (collision gas) MS/MS ALL (collision gas)

17 QTOFs - MS & MS/MS Simultaneous Full Scan & MS/MS Data dependent MS/MS MS E (collision gas) MS/MS ALL (collision gas) Can we do this with QQQs?

18 QQQs have traditionally had superior detection capabilities, precision and been more robust But They traditionally have only seen what they are looking for The list of what we are looking for in a single run is now much greater and scan speeds are now much faster Traditionally QQQs have had inferior sensitivity in full scan mode and collision gas causes dissociation of traditional EI spectra

19 QQQs? Can we Do More with LESS

20 QQQ SIMULTANEOUS VIEWS OF FULL SCAN, MRM

21 Simultaneous MRMs & Scan Multiresidue Scheduled MRM method for >100 compounds Optimised dwell times for MRMs using software Overlaid with full scan Concentration range 10 ppb to 1000 ppb Optimisation of CID pressure Monitor Library match as a function of scan dwell time & concentration Vary Scan Dwell times ms

22 CID Gas Pressure

23 80 ms dwell time (response) LOD tests

24 Can we still library search?

25 Can we still library search? YES

26 A Metabolomics approach to chemical exposure analysis

27 B50 cells + Malathion 6 h 24 h 48 h + 200μg/mL Malathion

28 Tryptophan 2 TMS isomer 1 3-Hydroxyanthranilic acid 3 TMS Kynurenine 2 TMS 3-hydroxykynurenine 3 TMS Kynurenic acid 2 TMS Tryptophan 2 TMS isomer 2 Anthranilic acid 2 TMS Kynurenine 3 TMS 5-hydroxyindole-3-acetic acid 3 TMS Tryptamine 3 TMS 3-hydroxyanthranilic acid 2 TMS 24hr 24hr 24hr 24hr The analytes detected from the tryptophan pathway using GC-Q-MS in Scan mode Detected At detection limit Not detected

29 Tryptophan Pathway hr hr hr 24hr 2 TMS 2 TMS 2 TMS hr hr hr Not detected hr 2 TMS TMS hr

30 Tryptophan 2 TMS isomer 1 3-Hydroxyanthranilic acid 3 TMS Kynurenine 2 TMS 3-hydroxykynurenine 3 TMS Kynurenic acid 2 TMS Tryptophan 2 TMS isomer 2 Anthranilic acid 2 TMS Kynurenine 3 TMS 5-hydroxyindole-3-acetic acid 3 TMS Tryptamine 3 TMS 3-hydroxyanthranilic acid 2 TMS 24hr 24hr 24hr 24hr Tryptophan 2 TMS isomer 1 Up to 2-3 orders of 3-Hydroxyanthranilic acid 3 TMS Kynurenine 2 TMS 3-hydroxykynurenine 3 TMS Kynurenic acid 2 TMS Tryptophan 2 TMS isomer 2 Anthranilic acid 2 TMS magnitude Kynurenine 3 TMS 5-hydroxyindole-3-acetic acid 3 TMS Tryptamine 3 TMS 3-hydroxyanthranilic acid 2 TMS From 24hr 24hr 24hr 24hr 1 compound detected to 10 compounds detected improvement in LODs The analytes detected from the tryptophan pathway using GC-Q- MS in Scan mode Detected At detection limit Not detected The analytes detected from the tryptophan pathway using GC-QQQ- MS in Full Scan/MRM mode

31 Can we improve on this?

32 Human Cell Lines Dose Curves & Time Curves Pesticide Challenges Cell Protection with Cannabinoids Model transformations in appropriate cell lines Toxicology data for chemical use

33 Future Aims Measure chemicals, their metabolites and the biochemical pathway perturbations to understand health implications Relate this to individual genomes Identify alleles that are common in exposure issues to build a predictive model

34 Thankyou for your attention

35 Acknowledgements Funding & Support NCRIS WA Government Bioplatforms Australia Metabolomics Australia EIF ARC LIEF & ARC Linkage Murdoch University CBH GWRDC GRDC Bruker Bong Sze How Steve Schachterle Jon Hall Brett Long Jack Cochran Our Many Collaborators Collaborator Naomi Trengove

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