European Reference Laboratory - FV

Samanta Uclés, Amadeo Fernández-Alba

European Reference Laboratory - FV

HIGH FAT AND PROTEIN CONTENT

COMMODITIES

20 – 30% Fatty Acids

(Palmitic, oleic and

linoleic)

And triglycerides

≈99% Fatty Acids

(Palmitic, oleic and

linoleic)

PROTEIN CONTENT

25% Proteins

5% Fat 25% Proteins

HIGH FAT CONTENT

European Reference Laboratory - FV

Tomato

(1 g/mL)

Bee Pollen

(0,5g/mL)

Co-extracted matrix components.

LC-QTOF-MS

Lentils

(0,2g/mL)

Avocado

(0,5g/mL)

Olive oil

(0,2g/mL)

Injection volume: 4 μL

European Reference Laboratory - FV

CONSEQUENCES OF «DIRTY» MATRICES

LC-QqQ-MS/MS

Skimer

After 30 injections

GC-Q-MS Liner after

40 injections

Injecting 1 g sample/mL

European Reference Laboratory - FV

0 50 100 150 200 250

Solvent

Matrix 1 (LC-ESI-MS)

Matrix 2 (LC-ESI-MS)

Matrix 1 (GC-MS)

Matrix 2 (GC-MS)

Concentration

Sig

nal

European Reference Laboratory - FV

LC-TOF-MS XIC of Tomato matrix compounds and Isoproturon (207.1492 ±20

ppm)

Isoproturon

(100 µg kg-1 )

LC-TOF-MS XIC of Orange matrix compounds and Isoproturon (207.1492 ±20 ppm)

Isoproturon (100 µg kg-1 )

European Reference Laboratory - FV

STUDIES Fast freezing out and new sorbents

(SPE and dSPE)

European Reference Laboratory - FV

-78ºC

FAST FREEZING OUT

DRY ICE

EFFICIENT LIPID AND PROTEIN*

REMOVAL BY PRECIPITATION

REDUCING TIME

TO A FEW MINUTES

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FREEZING OUT STEP REPRODUCIBILITY

SAME QUANTITY

OF DRY ICE

SAME TIME TO AN

EQUAL VOLUME

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QuEChERS (Pollen) QuEChERS + Fast Freezing out CO2

clean-up

Olive oil with Freezing out TIC 4.21E+10

Olive oil TIC 7.36E+10 TIC Olive Oil GC-QTOF-MS

7919 Compounds 9215 Compounds

Co-extracted matrix components of Pollen LC-QTOF-MS

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1049 Compounds

QuEChERS Citrate +Fast Freezing Out

1016 Compounds

QuEChERS Citrate

Lentils LC-QTOF Full scan chromatograms

Co-extracted matrix components of Tomato (0.1 g/mL). LC-QTOF-MS

European Reference Laboratory - FV

IN SOME COMMODITIES COEXTRATIVES

REMOVAL IS NOT ENOUGH AND

ADDITIONAL CLEAN UPS ARE NECESSARY

European Reference Laboratory - FV

OLIVE OIL

Clean ups

After Freezing Out

0

10

20

30

40

50

60

>120 70-120 60-70 20 ND

% o

f C

om

po

un

ds

RSD (%)

LC

n=167

European Reference Laboratory - FV

OLIVE OIL

Clean ups

After Freezing Out

0

10

20

30

40

50

60

70

80

90

0 - 5 (5 - 10) (10 - 20) >20 ND

% o

f C

om

po

un

ds

RSD (%)

0

10

20

30

40

50

60

70

60-120% 40-60%

European Reference Laboratory - FV

ZIRCONIUM DIOXIDE (Z-SEP)

Interaction of phospholipid

molecule with empty d-

orbital of zirconium atom.

Zirconium dioxide surface acts as:

• Brønsted acid (adsorption of anions in low pH via electrostatic interaction)

• Brønsted base (adsorption of cations in high pH via electrostatic interaction)

• Lewis acid (adsorption of Lewis bases via coordination bond with Zr atoms)

European Reference Laboratory - FV

LC-QTOF Full scan chromatograms of

avocado and lentils extracts with

different sorbents

Avocado

Lentils

European Reference Laboratory - FV Co-extracted matrix components of avocado with Z-Sep and PSA+C18. LC-TOF/MS

dSPE PSA+C18 4067 matrix compounds

dSPE Z-Sep 2907 matrix compounds

0

20

40

60

80

100

70-120% 60-70% ND

% o

f C

om

po

un

ds

Recoveries 10 µg/kg50 µg/kg

LC-MS/MS

0

20

40

60

80

100

>20% 10-20% 5-10%

European Reference Laboratory - FV

Co-extracted matrix components of avocado with Z-Sep and PSA+C18. LC-TOF/MS dSPE PSA+C18

4067 matrix compounds dSPE Z-Sep

2907 matrix compounds

0

20

40

60

80

>20 10-20% 5-10%

European Reference Laboratory - FV

7919 Compounds

2299 Compounds

Co-extracted matrix components of POLLEN (0.5 g dry sample/ml). LC-QTOF-MS

QuEChERS Citrate + Freezing out

QuEChERS Citrate + Freezing out + PSA&C18+SPE ZrO2

9215 Compounds

QuEChERS Citrate

Multiple Clean up Steps:

- ≈ 7000 Compounds BEE POLLEN

European Reference Laboratory - FV

0

50

100

ND< 60%

60-70 %70-120 %

4 6 8

82

0 6 7

87

% o

f co

mp

ou

nd

s

Recoveries – Pollen Data

5 ppb

50 ppb

4 10

24

62

0 0 6

25

69

0 0

20

40

60

80

ND < 5% 5-10 % 11-20 % > 20 %

% o

f c

om

po

un

ds

Intra-day precision

Matrix Compounds

Pesticides

n=251

European Reference Laboratory - FV

CONCLUSIONS Sample extraction procedures should be adapted in the

case of dealing with difficult commodities.

Fast freezing out can remove a significant number of

coextractives in a easy and quick way.

Cleaner extracts were obtained by the implementation of

different sorbents during the validation procedure.

European Reference Laboratory - FV

European Reference Laboratory - FV

Thank You

for Your Attention

www.eurl-pesticides.eu

European Reference Laboratory - FV

Samanta Uclés, Amadeo Fernández-Alba