Analysis of pesticides, POPs and emerging contaminants in catfish

Yelena Sapozhnikova

United States Department of Agriculture,

Agricultural Research Service, Wyndmoor, PA, USA

US seafood import

Year Million metric tons

2014 2.6

2015 2.7

2016 2.8

Freshwater imported fish, 2016

http://www.st.nmfs.noaa.gov/commercial-fisheries/foreign-trade/

US freshwater fish import

21%

http://www.st.nmfs.noaa.gov/commercial-fisheries/foreign-trade/

US catfish import

•Vietnam, China, Cambodia

Nutrients in catfish

Omega-3 fatty

acids:

Amino acids:

Vitamins:

Niacin: 2.105 mg

Vitamin B-12: 2.88 mg

Vitamin A: 1 mg

Vitamin E: 0.81

Vitamin D (D2+D3): 0.2 µg

Vitamin D: 9 IU

Vitamin K: 2.1 µg

20:5 n-3 (EPA): 0.015 g

22:6 n-3 (DHA): 0.057 g

Leucine: 1.153 g

Lysine: 1.386 g

Aspartic acid: 1.487 g

Arginine: 0.951 g

Alanine: 0.860 g

Nutrients per 100 g

Organic contaminants

POPs

PCBs

Toxic stable OC pesticides

PBDEsPAHs

Emerging environmental contaminants

Flame retardants

• Phase-out of some PBDE commercial mixtures => increasing number of alternate flame retardant chemicals

• Large volume production chemicals used in textiles, electronics and other consumer products

Multi-class, multiresidue method

Pesticides

Polychlorinated biphenyls (PCBs)

Polycyclic aromatic hydrocarbons (PAHs)

Polybrominated diphenyl ethers (PBDEs)

Novel alternate flame retardants (FRs)

250

total

Advantageous analytical technique

SimpleHigh throughput

Efficient Green

Inexpensive Fast

Sample preparation - QuEChERS

Quick Easy Cheap Effective Rugged Safe

• Add 10 mL MeCN

• shake 10 min on vortex shaker

10 g of homogenized tissue + Internal

standards

• Add 4 g anh. MgSO4 & 1 g NaCl, shake 1 min

• centrifuge 3 min at 4150 rpm

Phase separation

• Add 1 mL extract to 150 mg anh. MgSO4, 50 mg Z-Sep

• Shake 1 min, centrifuge, filtrated-SPE cleanup

Sapozhnikova, Journal of Agricultural and Food Chemistry, 2014, 62, 3684-3689

150 pesticides, 50 environmental contaminants & 12 internal standards

16

>200 analytes in 10 min

Low pressure (vacuum outlet) GC

Solvent delay

Recoveries:

Method validation

Accuracy: 72 - 120%

p,p’-DDT - 52%

p,p-DDD – 45%

PCBs

PBDEs

Pesticides

PCBs

PAHs

Pesticides

IS: atrazine-d513C12-p,p’-DDE

Catfish analysis

• Farm raised catfish samples

• USA: catfish• Vietnam: swai• China: catfish & basa• Cambodia: swai

•

Pesticides in catfish, ng/g

Pesticides in catfish, ng/g

“In aquaculture products imported from Viet Nam, there

were notifications for trifluralin in Pangasius spp.

products, three of which also contained chlorpyriphos”.

Environmental contaminants in catfish, ng/g

PAHs

Flame retardants

Acknowledgements

• USDA/ARS:

• Dr. Steve Lehotay

• Tawana Simons

• Jennifer Cassidy

Questions?