Comparison between Different Extraction Methods for Determination of Primary Aromatic Amines in Food Simulant

Abstract

The primary aromatic amines (PAAs) are food contaminants which may exist in packaged food. Polyurethane (PU) adhesives which are used in flexible packaging are the main source of PAAs. It is the unreacted diisocyanates which in fact migrate to foodstuff and then hydrolyze to PAAs. These PAAs include toluenediamines (TDAs) and methylenedianilines (MDAs), and the selected PAAs were 2,4-TDA, 2,6-TDA, 4,4'-MDA, 2,4'-MDA, and 2,2'-MDA. PAAs have genotoxic, carcinogenic, and allergenic effects. In this study, extraction methods were applied on a 3% acetic acid as food simulant which was spiked with the PAAs under study. Extraction methods were liquid-liquid extraction (LLE), dispersive liquid-liquid microextraction (DLLME), and solid-phase extraction (SPE) with C18 ec (octadecyl), HR-P (styrene/divinylbenzene), and SCX (strong cationic exchange) cartridges. Extracted samples were detected and analyzed by HPLC-UV. In comparison between methods, recovery rate of SCX cartridge showed the best adsorption, up to 91% for polar PAAs (TDAs and MDAs). The interested PAAs are polar and relatively soluble in water, so a cartridge with cationic exchange properties has the best absorption and consequently the best recoveries.

Figure 1

Compressive of recoveries of extraction methods: LLE, DLLME, SPE C18 ec, SPE HR-P, and SPE SCX for 5 primary aromatic amines.

Figure 2

Chromatogram of the standard solution (100 ppb). Peak identified as a: 2,6-TDA, b: 2,4-TDA, c: 4,4′-MDA, d: 2,4′-MDA, and e: 2,2′-MDA.

Figure 3

Chromatogram of extracted sample spiked (15 ppb) in 3% acetic acid with SPE SCX. Peak identified as a: 2,6-TDA, b: 2,4-TDA, c: 4,4′-MDA, d: 2,4′-MDA, and e: 2,2′-MDA.

Figure 4

Chromatogram of extracted sample spiked (15 ppb) in 3% acetic acid with LLDME. Peak identified as a: 2,6-TDA, b: 2,4-TDA, c: 4,4′-MDA, d: 2,4′-MDA, and e: 2,2′-MDA.

Figure 5

Chromatogram of extracted sample spiked (15 ppb) in 3% acetic acid with SPE C18. Peak identified as a: 2,6-TDA, b: 2,4-TDA, c: 4,4′-MDA, d: 2,4′-MDA, and e: 2,2′-MDA.

Figure 6

Chromatogram of extracted sample spiked (15 ppb) in 3% acetic acid with SPE HR-P. Peak identified as a: 2,6-TDA, b: 2,4-TDA, c: 4,4′-MDA, d: 2,4′-MDA, and e: 2,2′-MDA.

Figure 7

Chromatogram of extracted sample spiked (15 ppb) in 3% acetic acid with LLE. Peak identified as a: 2,6-TDA, b: 2,4-TDA, c: 4,4′-MDA, d: 2,4′-MDA, and e: 2,2′-MDA.