# Non-volatile substances extractible from inner coatings of metallic cans from the French market and their occurrence in the canned vegetables

Ronan Cariou, Matthieu Rivière, Sébastien Hutinet, Asmaa Tebbaa, Yann Guitton, Didier Dubreuil, Monique Mathe-Allainmat, Jacques Lebreton, Bruno Le Bizec, Arnaud Tessier, et al.

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## To cite this version:

Ronan Cariou, Matthieu Rivière, Sébastien Hutinet, Asmaa Tebbaa, Yann Guitton, et al. Non-volatile substances extractible from inner coatings of metallic cans from the French market and their occurrence in the canned vegetables. Analytics, Sep 2022, Nantes (France), France. hal-05399179

HAL Id: hal-05399179

https://hal.science/hal-05399179v1

Submitted on 4 Dec 2025

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Distributed under a Creative Commons Attribution 4.0 International License
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# Non-volatile substances extractible from inner coatings of metallic cans from the French market and their occurrence in the canned vegetables

Ronan CARIOU¹, Matthieu RIVIÈRE², Sébastien HUTINET¹, Asmaa TEBBAA¹,², Yann GUITTON¹, Didier DUBREUIL², Monique MATHE ALLAINMAT², Jacques LEBRETON², Bruno LE BIZEC¹, Arnaud TESSIER², Gaud DERVILLY¹

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LABERCA

Oniris, INRAE, LABERCA, Nantes, France

Fax : +33 (0)2 40 68 78 78 - Tél : +33 (0)2 40 68 78 80

laberca@oniris-nantes.fr

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SANTÉ ET ALIMENTATION AU CŒUR DE LA VIE

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CEISAM

Chimie et Interdisciplinarité
Synthèse, Analyse, Modélisation

²Nantes Université, CNRS, CEISAM, UMR 6230

F-44000 Nantes, France

## Introduction

Regulatory pressure against bisphenol A for food contact material (FCM) applications led **can coating** manufacturers to develop **polyester-based** alternatives. Besides intentionally added substances, the investigation of the presence of **non-intentionally added substances (NIAS)** has been raising the interest of the scientific community in response to manufacturers and consumers concerns. NIAS, generally of unknown structures, can be impurities from starting materials, degradation or decomposition products, contaminants from production process or oligomers principally formed during the synthesis of the coating. Such oligomers can be formed during resin synthesis or upon degradation over time. Although a wide range of reactions are possible (which poses an analytical challenge), these NIAS may be predicted since polyalcohols and carboxylic polyacids involved in the polycondensation reaction are generally known. In order to increase chemical food safety of packaging, it is now necessary to produce qualitative, quantitative and toxicological data.

This work aimed to contribute to the risk assessment of NIAS from polyester-based coatings by developing an **innovative analytical strategy** dedicated to their characterisation.

## Results and Discussion

~5,000 PC-groups
(~17,000 features)

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<figure><img src="image_10.png" /><figcaption>**Figure 4: Data mining in 40 coatings from 12 vegetable cans.**</figcaption></figure>

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<figure><img src="image_13.png" /><figcaption>**Figure 5: Oligoesters observed (84 monomer combinations; 38 out of the 40 coatings).**</figcaption></figure>

<figure><img src="image_14.png" /><figcaption>**Figure 6: Oligoesters migrating in the vegetables.**
(68 combinations; Mean: 330 µg/kg; Range: 43–1600 µg/kg)</figcaption></figure>

**Other identified IAS in the coatings:**

<figure><img src="image_15.png" /><figcaption>Epoxidised soybean oil</figcaption></figure>

<figure><img src="image_16.png" /><figcaption>ADK Stab NA 21E</figcaption></figure>

<figure><img src="image_17.png" /><figcaption>TPPO</figcaption></figure>

<figure><img src="image_18.png" /><figcaption>Irganox 3114</figcaption></figure>

<figure><img src="image_19.png" /><figcaption>DiNcH</figcaption></figure>

<figure><img src="image_20.png" /><figcaption>(Hydroxymethyl)benzoguanamine, methylated/ethylated</figcaption></figure>

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**Other identified NIAS in the coatings:**

-Benzoguanamine derivatives (n=13)

-Phenolic oligomers (n=5)

BG oligomers (up to 5 monomer units)

-BADGE derivatives (n=10; incl. 6 migrating into vegetables)

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## Experimental

12 cans
Supermarket
Vegetables
3PC, 2PC

Identification

**Coatings** (n=40)
Scraped
ACN extraction

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**Data acquisition**
Non-targeted analysis

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LC/ESI(+)-HRMS
Omer et al. (2018, 2019)
doi 10.1007/s00216-018-0968-z
doi 10.1016/j.chroma.2019.05.024

**Data mining**
Automated peak picking
Manual curation

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CAMERA

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NIAS-db 1.0

**Confidence level**

Adducts/fragments, t<sub>R</sub>, MS<sup>2</sup>

Databases (predictable)

Consistency, Literature

Standards if available

Level 1: Confirmed structure by reference standard

Level 2: Probable structure
a) by library spectrum match
b) by diagnostic evidence

MS, MS<sup>2</sup>, RT, Reference Std.

MS, MS<sup>2</sup>, Library MS<sup>2</sup>

MS, MS<sup>2</sup>, Exp. data

Level 3: Tentative candidates(s)
structure, substituent, class

MS, MS<sup>2</sup>, Exp. data

MS, MS<sup>2</sup>

Level 4: Unequivocal molecular formula

MS isotope/adduct

Level 5: Exact mass of interest

MS

(semi-)Quantification

Juice and drained **foodstuffs**

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**Sample preparation**

Lyophilisation

MAE extraction (Aco/DCM)

2 LLE (nHex/EtOH/H<sub>2</sub>O, DCM/H<sub>2</sub>O)

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**Data treatment**

Suspect screening

Automated integration

Manual curation

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LC/ESI(+)-HRMS

<figure><img src="image_32.png" /><figcaption>**Figure 2: Stepwise strategy** to access to native and D-labelled, linear or cyclic combinations, of NPG and iPA oligoesters. (i) Et3N, MeOH, H<sub>2</sub>O; (ii) BnBr, DMF; (iii) LAH, THF for 4-H<sub>4</sub> or LAD, THF for 4-D<sub>4</sub>; (iv) TBDMSCI, Et3N, DMAP, DCM; (v) EDC.HCl, DMAP, DCM; (vi) H<sub>2</sub>, Pd(OH)<sub>2</sub>, iPrOH; (vii) HF.Pyr, THF; (viii) EDC.HCl, DMAP, DCM; (ix) HF.Pyr, THF; (x) H<sub>2</sub>, Pd(OH)<sub>2</sub>, iPrOH; (xi) 2,4,6-trichlorobenzoyl chloride, Et3N, DMAP, 10 mM in THF.</figcaption></figure>

<figure><img src="image_33.png" /><figcaption>**Figure 3: Screen captures of NIAS-db software.** Open-source database of predictable combinations of 17 polyols with 15 polyacids (oligoesters) and phenol-formaldehyde oligomers. (Freely available at DOI 10.15454/HHY2Z2)</figcaption></figure>

## Conclusion

Using a non-targeted **LC/ESI(+)-HRMS** approach, dozens of small molecules in inner coatings of vegetable metallic cans have been identified. **Oligoesters**, a diverse family of unwanted compounds arising from the synthesis of polyesters, **prevailed** in the data set. This study sheds light on the need to fulfil a proper risk assessment on this NIAS family (exposure and hazard characterisation, including genotoxicity and endocrine disruption).

**Detailed information in DOI 10.1016/j.jhazmat.2022.129026.**