Migration of biocides from paperboard into food simulants and vegetables.

The migration of the biocides: 2-methyl-2H-isothiazol-3-one (MIT), 1,2-benzisothiazol-3(2H)-one (BIT) and 2-phenoxyethanol (PHE) from spiked paperboard into the simulants Tenax®, water and acetic acid (3%) has been studied and compared with that into the vegetables: red cabbage, lettuce and cauliflower. The migration of the biocides into the vegetables is significant and it shows the trend BIT > PHE > MIT, at both 4 °C and room temperature (RT), whatever tested foodstuff and with the highest value corresponding to BIT into cauliflower at RT (71%). Differences up to one order of magnitude between the biocides migration into Tenax® (<4.3%) and that into the vegetables indicate that Tenax® is not a suitable food simulant to mimic the selected vegetables in terms of the migration of the studied biocides. Water has been shown to be the most appropriate food simulant in the cases under study.

Occurrence of per- and polyfluorinated compounds in paper and board packaging materials and migration to food simulants and foodstuffs.

This work describes the screening of twenty three per- and polyfluoroalkyl substances (PFASs) in twenty five paper and board (P/B) packaging materials and their migration to several food simulants (50% ethanol, 95% ethanol and Tenax®) at different conditions of time and temperature. A different migration pattern depending on the carbon chain length was observed; while short carbon chain PFASs tend to migrate more to 50% ethanol than to 95% ethanol, long chain PFASs showed the opposite trend. On the other hand, very low migration percentages of all PFASs to Tenax® were found. Finally, migration of 9 PFASs into real foods (cereals, rice and infant milk powder) for 6 months was quantified and compared with the results obtained with the simulants. As a result, significant underestimations of the PFASs migration to foodstuffs were obtained using Tenax®, especially for short carbon chain PFASs and milk powder.

Determination of the degradation compounds formed by the oxidation of thiophosphinic acids and phosphine sulfides with nitric acid.

The degradation process that takes place at room temperature when bis(2,4,4-trimethylpentyl)monothiophosphinic acid (R2P(S)OH), bis(2,4,4-trimethylpentyl)dithiophosphinic acid (R2P(S)SH) and tris(2,4,4-trimethylpentyl)phosphine sulfide (R3PS) are in contact with 5 M HNO3 has been studied by FT-Infrared, FT-Raman spectroscopy and by gas chromatography with mass spectrometry detection (GC-MS). An exposure period of ten days of the rough reagents to 5 M HNO3 causes complete oxidation of the compounds. This process mainly leads to the formation of nitrogen dioxide, elemental sulfur and the oxo-analogues of the reagents. For dilute solutions of the reagents it was observed that after 15 min of contact with phase-shaking, R2P(S)OH and R3PS are completely oxidized to yield R2P(O)OH and R3PO, respectively, whereas for R2P(S)SH, the oxidation process is less severe, because the dithioacid is still present in the oxidized mixture, the oxidation products being R2P(S)OH and R2P(O)OH.

Component analysis of the commercial metal extractant, Cyanex 302, by GC-MS.

The composition of the commercial reagent Cyanex 302 was investigated by GC-MS. Mass spectrometric studies allowed us to confirm that bis(2,4,4-trimethylpentyl)monothiophosphinic acid is the major compound and that a considerable amount of tris(2,4,4-trimethylpentyl)phosphine oxide is also present. The study also revealed that the extractant has three minor components. These were identified as bis(2,4,4-trimethylpentyl)phosphinic acid, bis(2,4,4-trimethylpentyl)phosphine oxide and bis(2,4,4-trimethylpentyl)dithiophosphinic acid. The mass spectra of these compounds are discussed and some fragmentation processes are postulated.