# Chemical Migration from Wine Contact Materials
## 5 Wine Migration Studies on Chemical Contaminants
### Analytical Methods
#### 5.2.2 Liquid Chromatography  
Liquid chromatography coupled to low-resolution triple quadrupole mass spectrometry has been applied for the targeted analysis of phthalates [11], while ultra performance liquid chromatography coupled to ion-mobility and high-resolution time of flight (TOF) spectrometry has been applied for the wide-scope targeted and untargeted analysis of IAS and NIAS migrating from cork to wine simulants [74; 75] and champagne [75]. The analytical column used in all cases concerned reversed phase C18 sorbent, and the mobile phase consisted of water, and methanol acidified either with formic acid [74; 75] or with acetic acid [11]. The electrospray ionization (ESI) interface was operated in positive polarity for the phthalates [11] and for the compounds derived from polyurethane adhesives [75], while for the untargeted approach, the ESI was operated in positive and negative polarity mode [74]. In more detail, the LC triple quadrupole MS/MS method for the determination of phthalates used reference standards of BBP, DBP, DEHP, Di-isodecylphthalate (DiDP), Di-isopropyl phthalate (DIP), Di-isonomylphthalate (DiNP), Dimethyl isophthalate (DMIP), Diallylphthalate (DA), and Diphenyl phthalate (DPP). Two selected transitions were monitored for each compound, and their ratio was used to verify the identity of the analytes in samples in addition to the retention time. The method was validated for four selected phthalates, and the LOQs ranged from 0.15 mg/L (DBP) up to 0.57 mg/L (DiNP), while no quantification results from the migration tests were reported [11]. Recently, a wide-scope study applying ultra high pressure liquid chromatography in combination with ion mobility-quadrupole time of flight analyzer (UPLC-IM-Q/TOF) focused on the determination of compounds derived from polyurethane adhesives used in champagne cork tops [75]. The analytical methodology started with the analysis of the migration extracts of the wine simulants and the analysis of the diluted champagne samples, 1/10 \(v/v\) with ultrapure water by UPLC-IM-Q/TOF. Ion mobility spectrometry (IMS) constitutes an additional identification feature. The ions need a \"drift time\" to cross the drift cell, which is used for the generation of a collision cross-section (CCS) value for each compound. The CCS value is an intrinsic property of the molecule and is related to its 3D conformation. It is a useful tool to discriminate between isobaric and isomeric species. The generated spectra after ion mobility are simplified because the fragment ions of a detected compound are associated with the precursor ion for that compound using not only the retention time but the drift time as well. Data were acquired in the range of 50-1000 \(m/z\), and data independent analysis was set to high-definition mass spectrometry. This technique provided separation of the LC eluted compounds by means of ion mobility, mass accuracy, fragment ions, and retention time. The unknown compounds were first attributed to an elemental composition based on the \(m/z\) of the precursor ion. Afterward, a database search using ChemSpider proposed compounds, including their structure for each elemental composition, and then _in silico_ fragmentation was applied to each structure in order to compare the \(m/z\) of the proposed fragment ions to the \(m/z\) of the actually generated fragment ions. The application of this analytical methodology resulted in the identification of twelve new compounds, which were amines, amides, and urethanes, formed from the reaction between the isocyanates and acetic acid or ethanol, used as food simulants, and in the identification of four new compounds generated from the reaction between the disocyanates and malic acid or tartaric acid contained in champagne. The identified compounds were subsequently quantified or semi-quantified using UPLC coupled to a triple quadrupole mass spectrometer in the MRM mode and certified standards of 1,6-hexanediamine and isophorone diamine.