Approaches for the determination of

NIAS as a part of Safety-By-Design

M. Driffield1, M. Garcia-Lopez1, E.L. Bradley1, P.T.K. Oldring2 1Fera Science Ltd, 2Valspar Corp.

malcolm.driffield@fera.co.uk

What can migrate from FCMs?

• Known ingredients such as monomers, catalysts, solvents,

suspension media, additives, etc.

• Known or unknown isomers, oligomers (arguably not NIAS),

impurities, reaction products and breakdown products of

these ingredients

• Possible contaminants from the manufacturing process

such as recycled materials, irradiated products, etc.

• Contamination from indirect sources such as printing inks,

external coatings, adhesives, secondary packaging, etc.

IAS

NIAS

NIAS analytical workflow

Reporting

Data interpretation

Analysis

Extraction or migration experiments

Sample preparation

Initial discussions with Sponsors

Identification

Quantification

0 50 100

NM

R in

teg

ral valu

e

Concentration

TIC vs. EIC?

vs.

Detection

Detection of NIAS – Instrumentation

2000 2016

• Generally non-

selective detectors

• Little structural

information on

unknowns

• Limited MS

information - unit

mass resolution

• GC-MS with

searchable libraries

• LC-MS infancy

• LC-HR-MS routinely

used

• Accurate mass and

high resolution

• Structural data

from controlled

fragmentation

• GC-TOF-MS provides

access to HR-MS for

volatiles and semi-

volatiles

Detection of NIAS - Software

2000 2016

• Software designed for

non-targeted analysis

• Much more information

extracted from the data

sets

• Advanced statistics allow

comparison of complex

data

• Limited useful software

available

Identification of NIAS

2000 2016

• Analytical tools (hardware

and software) including:

• HR-MS

• Accurate mass

• Isotope

information

• Controlled

fragmentation

• NMR

• Comprehensive user-

prepared databases

?

?

?

• Manual data

interrogation

• Time consuming

Close working relationship between the Analytical Chemist and Coating Manufacturer

Quantification of NIAS

2000 2016

Universal detectors

• Comparison of

structurally similar

substances to

standards e.g. BADGE

related substances

using LC-FLD

• OM, %LMWF vs. TIC

• Some internal

standards

• More internal standards

• Structurally related

oligomer standards

• Standard addition

• Authentic standards if

available

• NMR vs. LC-MS

State-of-the-art (2016): Safety-By-Design

• Guides product development to the most appropriate low

risk solutions e.g. from a coatings company:

Product Development Ideation

Material Investigation Process

Monitoring Chemicals of Concern

Endocrine Activity Testing

Toxicological Testing

Migration Analysis

International Food Contact & Chemical Inventory Regulatory Approvals

State-of-the-art (2016): Safety-By-Design - Profiling

• What is the effect of changing an ingredient or processing

temperature or site of manufacture on the NIAS profile?

• For example using the advanced statistical methods to

investigate NIAS variation from the same coating applied

at different locations:

Industrial application company A

Industrial application company B

Laboratory application A

Laboratory application B

Laboratory application C

Laboratory application D

State-of-the-art (2016): Modified coatings

• In support of a petition for a new

monomer (non-BPA epoxy) it was

necessary to investigate oligomers

related to that monomer

• A modified coating was prepared

• Non-BPA epoxy monomer was

substituted by BADGE whilst keeping

everything else the same

• All masses detected in the modified

coating and the original coating

could not be related to the

monomer of interest

Original coating

Modified coating

Original coating

Modified coating

State-of-the-art (2016): Databases

• Analytical data can be compared to theoretical databases

of accurate masses of oligomers and reaction products

associated with starting materials and impurities below

1000 Da

• Can include retention time, structures, MS/MS fragment

data

• Mass differences of +/- 5 ppm (parts-per-million of the

accurate mass) or better

• Can contain tens of thousands of substances but each

match needs sense checking

• Should consider simulant-oligomer interactions

State-of-the-art (2016): Migration into food

• Due to the complexity of measuring known substances

directly in foodstuffs, solvents and simulants are

frequently used

• For NIAS (where unknown substances are detected)

this is even more challenging

• Food simulants are defined in plastics legislation to

over-estimate migration into foodstuffs

• Foodstuffs have been examined to see if simulants do

in fact over-estimate migration of monomers and

oligomers

• Initial results reported here but the work is on-going

Migration into food: Experiments

• Foodstuffs packed in cans with a polyester coating

(containing nadic acid), stored up to 3 years, were analysed

for the presence of monomers and oligomers

• The same foodstuffs packed in non-polyester coated cans

used as control samples

• Generic solvent extraction with minimal clean-up and

LC-TOF-MS analysis

• Profiling software used to identify substances present in the

extract from the polyester and not a component of the food

• Comparison to database of oligomers

• Concentrations estimated using polyester oligomer standard

[1] Fera data

[2] Data from Paseiro-Cerrato et al. J. Agri. Food Chem. (2016) 64 (11) 2377-2385

Solvent or

simulant Processing conditions

Estimated concentration of oligomer

(μg/6 dm2)

A B C D E F G H I

Acetonitrile1 Room temperarure for 24

hours nd 96 124 19 nd nd 77 nd 68

water2 121oC for 2 hours followed

by 515 days at 40oC 450 462 156 90 132 138 114 nd nd

10% ethanol2 121oC for 2 hours followed

by 515 days at 40oC 438 912 1224 162 384 1602 324 nd nd

50% ethanol2 No retort - 515 days at

40oC 402 1002 1830 192 462 2262 192 498 1296

Migration into food: Oligomers

Food Processing conditions Estimated concentration of oligomer (μg/kg)

A B C D E F G H I

Green beans1 sterilised and stored for

730 days at ambient nd nd 6.9 nd 13 9.0 nd nd nd

Wax beans1 sterilised and stored for

450 days at ambient 1.3 8.2 20 15 16 27 1.3 3.6 1.6

Peas1 sterilised and stored for

500 days at ambient 8.0 12 16 5.4 28 39 7.8 5.7 12

A = IPA+MPD

B = NA+CHDM

C = IPA+2MPD

D = 2IPA+2MPD

E = NA+MPD+CHDM

F = IPA+CHDM+MPD

G = IPA+NA+2MPD

H = 2IPA+2MPD+CHDM

I = IPA+NA+CHDM+MPD

IPA = isophthalic/terephthalic acid

NA = nadic acid

MPD = 2-methylpropane-1,3-diol

CHDM = cyclohexane dimethanol

[1] Fera data

[2] Data from Paseiro-Cerrato et al. J. Agri. Food Chem. (2016) 64 (11) 2377-2385

Solvent or

simulant Processing conditions

Estimated concentration of oligomer

(μg/6 dm2)

A B C D E F G H I

Acetonitrile1 Ambient for 24 hours nd 96 124 19 nd nd 77 nd 68

water2 121oC for 2 hours followed

by 515 days at 40oC 450 462 156 90 132 138 114 nd nd

10% ethanol2 121oC for 2 hours followed

by 515 days at 40oC 438 912 1224 162 384 1602 324 nd nd

50% ethanol2 No retort - 515 days at

40oC 402 1002 1830 192 462 2262 192 498 1296

Migration into food: Oligomers

Food Processing conditions Estimated concentration of oligomer (μg/kg)

A B C D E F G H I

Green beans1 Sterilised and stored for

730 days at ambient nd nd 6.9 nd 13 9.0 nd nd nd

Wax beans1 Sterilised and stored for

450 days at ambient 1.3 8.2 20 15 16 27 1.3 3.6 1.6

Peas1 Sterilised and stored for

500 days at ambient 8.0 12 16 5.4 28 39 7.8 5.7 12

Migration into food: Monomers

Solvent/simulant Processing conditions Nadic acid concentration

(μg/6 dm2)

Acetonitrile1 room temperature for 24 hours nd (LOD = 1.7)

Acetonitrile2 40oC for 24 hours 1.8

Acetonitrile3 room temperature for 24 hours nd (LOD = 24)

50% ethanol2 515 days at 40oC 19

50% ethanol3 130oC for 1 hour 42

10% ethanol2 121oC for 2 hours followed by 515 days at 40oC 46

3% acetic acid3 130oC for 1 hour 18

water2 121oC for 2 hours followed by 515 days at 40oC 3.0

Foodstuff Processing conditions Nadic acid concentration

(μg/kg)

Green beans1 sterilised and stored for 730 days at ambient <5.0 (n = 6)

Green beans1 sterilised and stored for 730 days at ambient 5.6 (n = 6)

Tomato sauce1 sterilised and stored for 990 days at ambient <0.30 (n = 3)

Diced tomatoes1 sterilised and stored for 1050 days at ambient <0.22 (n = 4)

Tomatoes + chillies1 sterilised and stored for 1050 days at ambient <0.22 (n = 4)

[1] Fera data

[2] Data from Paseiro-Cerrato et al. J. Agri. Food Chem. (2016) 64 (11) 2377-2385

[3] Data from another laboratory

Migration into food: Summary

• Whilst the results for this coating show that the

simulants exaggerate monomer migration, it is clear

that for the selected oligomers, simulants greatly

over-estimated the migration into the foods tested

State-of-the-art (2016): LC-QTOF-MS

• Controlled fragmentation experiments can lead to

more data on structural information of peaks

• Characteristic fragments related to the non-BPA

epoxy monomer can be used to further assign related

peaks

• Differentiation between linear and cyclic oligomers

CH2

+CH3

CH3

OH

CH3 CH2

+

O

CH3O

CH3 CH2

+

O

CH3

OH

OH

State-of-the-art (2016): NMR

Extraction of a

FCM with

solvent

AA TMA PA CHDM BD EG DEG PG HD HMP TMP NPG H2O MW

PA+EG linear 1 1 1 210.0528

EG+PA+EG linear 1 2 2 254.0790

PA+EG+PA+EG linear 2 2 3 402.0951

PA+EG+PA+EG cyclic 2 2 4 384.0845

PA+EG+PA+EG+PA linear 3 2 4 550.1111

PA+EG+PA+EG+PA+NPG linear 3 2 1 5 636.1843

PA+EG+PA+NPG+PA+EG linear 3 2 1 5 636.1843

PA+PG+PA+PG+PA+PG linear 3 3 5 636.1843

PA+PG+PA+PG+PA+PG cyclic 3 3 6 618.1737

0 50 100

NM

R in

teg

ral valu

e

Concentration

0.04 mg/6 dm2

0.03 mg/6 dm2 Monomer functional

group quantification

Oligomer determination

0

20

40

60

80

100

120

0 50 100 150

Are

a

Concentration

Summary

• Safety-By-Design is an integrated alternatives

assessment program that guides the product

development process to the most appropriate low risk

solution

• Ever-advancing analytical instrumentation provides

very powerful tools for determination of NIAS

• As instruments become more readily available and

sensitivity increases there is the potential for more

and more NIAS to be detected

Acknowledgements

• Julie Christy

• Antony Lloyd

• Jonathan Tarbin

• Patrick Hough

• Danny Chan

• James Donarski