Recent Development in Chemical Contaminants Analysis in Food

Li FangyanAnalytical Scientist

Food Safety DivisionHealth Science Authority, Singapore

24th Nov 2011

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Overview of presentation

Definition of food contaminants

International legislation

Contaminant analysis: method and instrumentation

Conclusion

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European Commission regulates the following:

- mycotoxins (aflatoxins, ochratoxin A, fusarium-toxins, patulin)- metals (cadmium, lead, mercury,inorganic tin)- dioxins and polychlorinated biphenyls (PCBs)- polycyclic aromatic hydrocarbons (PAHs)- 3-monochloropropane-1,2-diol (3-MCPD) and nitrates.Chemicals for which investigations are ongoing:- Acrylamide- Organotin- Furan- Ethyl carbamate- Perfluoroalkyl sulfonate (PFAS)

Food contaminantsFood contaminants are substances that may be unintentionally present in certain foodstuffs due to environmental contamination, cultivation practices or production processes.

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EU legislation:The basic principles - Council Regulation 315/93/EEC of 8February 1993 :- food containing a contaminant to an amount unacceptable fromthe public health viewpoint and in particular at a toxicological level,shall not be placed on the market- contaminant levels shall be kept as low as can reasonably beachieved following recommended good working practices-maximum levels must be set for certain contaminants in order toprotect public health

Commission Regulation (EC) No 1881/2006

nitrate, mycotoxins (aflatoxins, ochratoxin A, patulin,deoxynivalenol, zearalenone, fumonisins), metals (lead, cadmium,mercury, inorganic tin), 3-MCPD, dioxins and dioxin-like PCBsand PAHs (benzo(a)pyrene).

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Codex Alimentarius defines contaminantscontaminants as: "Any substance not intentionally added to food, whichis present in such food as a result of the production(including operations carried out in crop husbandry,animal husbandry and veterinary medicine),manufacture, processing, preparation, treatment,packing, packaging, transport or holding of such foodor as a result of environmental contamination. Theterm does not include insect fragments, rodent hairsand other extraneous matter".

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Codex Alimentarius legislation:

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Legislation:

- Agri-Food & Veterinary Authority (AVA)

- 9 statutes, food contaminants under Sale of Food Act

Food Legislation in Singapore

Heavy metals;

Mycotoxins;

Monitoring other contaminants e.g, 3-MCPD, PCBs, PAHs

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Food Safety Division, HSA- National laboratory that supports AVA in ensuringa safe food supply to the consumers in Singapore.

- EC-ASEAN Reference Laboratory for mycotoxins

- WHO Collaborating Centre For FoodContaminants Monitoring

Food Legislation in Singapore

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Determination of 15 EU priority Determination of 15 EU priority PAHs in food by GCPAHs in food by GC--MS/MSMS/MS

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PAHs in food by GC-MS/MS

PAHs:-Two or more aromatic rings fused together;

- Environmental contaminants: combustion and pyrolysis;

- Lipophilic; fish, meat, oil, vegetable, fruits, etc

- Some are carcinogens;

- In 2002, EU identified 15 PAHs as priority as of majorconcern for human health; in 2005, an additional PAH-benzo[c]fluorene was included.

- Benzo[a]pyrene is used as a marker for the occurrence andeffect of carcinogenic PAHs in food

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Benzo[g,h,i]perylene

Dibenzo[a,l]pyrene Dibenzo[a,e]pyrene Dibenzo[a,i]pyrene Dibenzo[a,h]pyrene

Indeno[1,2,3-c,d]pyrene Dibenz[a,h]anthracene

Cyclopenta[c,d]pyrene Benz[a]anthracene Chrysene 5-Methylchrysene

Benzo[b]fluoranthene Benzo[j]fluoranthene Benzo[k]fluoranthene Benzo[a]pyrene

PAHs in food by GC-MS/MS

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PAHs in food by GC-MS/MS

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PAHs in food by GC-MS/MS

Methodology:

Extraction: LLE,SLE, Saponification,Soxhlet, PLE, SPE,SPME, MAE, QuEChERS

Clean-up: GPC, SPE, Column chromatography

Detection: LC-FLD, GC-MS, LC-UV, GC-MS/MS

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PAHs in food by GC-MS/MS

For oil samples: Dilution, SPE cartridge;For solid samples: 1) Accelerated Solvent Extraction (ASE);

2) SPE cartridge

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PAHs in food by GC-MS/MS

Detection:

Waters® Quattro Micro GC-MS/MS

GC:

Column: DB- 5MS, 30 m x 0.25 mm id x 0.25 µm dfBack inlet: Splitless mode, 2 µL inj volRun time: 33 min

MSMS:Ionization source: EI modeAcquisition mode: MRM

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PAHs in food by GC-MS/MS

Performance of the method:

Precision: repeated analysis of FAPAS material - olive oil

repeatability, expressed as RSD all < 5%

Acurracy: FAPAS Proficiency Test – Palm Oil T0648

Test(s) Assigned Value(s) (µg/kg)

Result(µg/kg) Z- score

Benzo[a]pyrene 0.99 1.02 +0.1

Indeno[1,2,3-cd]pyrene 0.88 0.83 -0.3

Benzo[g,h,i]perylene 0.91 0.87 -0.2

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PAHs in food by GC-MS/MS

Advantages:- Simple, less laborious, reduced solvent usage, less interference

3 isomers of Benzofluoranthene b, j, k

Benz[a]anthracene Chrysene

Limitation of DB-5 MS column:- Critical pairs not fully separated

252>250

252>226

228>226

228>202

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Detection of Radionuclides by Detection of Radionuclides by GammaGamma--Ray SpectrometryRay Spectrometry

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CODEX GENERAL STANDARD FOR CONTAMINANTS AND TOXINS IN FOOD AND FEED

Regulation:

Detection of radionuclides in food

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NaI Scintillation Detector

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NaI Scintillation Detector

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Pre-screening

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Analysis of results

Measurement in detectorSample Preparation

Radiation testing procedure in FSD

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No. of products screened since 15 March : 2500

CategoryCategory Types of food screened for radioactivityTypes of food screened for radioactivity

Seafood Fish (Mackerel, Tuna, etc.), Molluscs, Eels, Seaweed, etc.Vegetable Leeks, Radish, Carrots, Lettuces, Onions, Beans, etc.Tea Chrysanthemum, Green tea, Brown Rice tea, etc.Fruit Lime, Strawberry, Apple, etc.Mushroom Shitake mushroomGrain RiceProcessed Food Ice-cream, wasabi seasoning, yam paste, etc.

No. of positive samples: 15Category of positive samples: rapeseed leaves(nanohana), mitsuba (Japanese wild parsley), spinach,cabbage, leek, eggplant, mushroom ,green tea, Shen Cha

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Conclusion

- Regulation needs to be strengthened so as tocontrol different types of chemical contaminants infood.

- New/improved methods need to be developed toaddress the emerging challenges.

- There is a need to build up capabilities to handleemergencies

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Acknowledgement

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- Joanne Chan, Director of Food Safety Division, HSA

- All staff from FSD, HSA

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THANK YOU FOR YOUR ATTENTION.