The reaction of 2-pyrimidone hydrochloride ([C(4)H(5)N(2)O](+)[Cl](-) or [PMOH(2)](+)[Cl](-)) with diiodine in a dichloromethane-methanol solution resulted in the formation of ([C(4)H(5)N(2)O](+))(2)[I(2)Cl(2)](2-) (1) complex. The compound was characterized by elemental analysis, FT-IR, DTA-TG and conductivity titrations. The crystal structure of 1 was also determined by X-ray diffraction at 294(1) K. Compound 1 is monoclinic, space group P2(1)/n, consisting of two cationic [PMOH(2)](+) species and a [I(2)Cl(2)](2-) counter dianion. The cation is in its keto form. Direct reaction of thiazolidine-2-thione (tzdtH), with diiodine in dichloromethane solution, on the other hand, led to the formation of a crystalline solid which contained two complexes of formulae [(tzdtH)(2)I](+)[I(3)](-).2I(2) (2) and [(tzdtH)I(2)](2).I(2) (2a) in a ratio of 90 to 10%. Complex 2a was characterized by X-ray analysis at 180(2) K. Compound is monoclinic, space group C2/c and contains two units of [(tzdtH)I(2)] "spoke" structures. Compound 1, as well as the known species iodonium salt [(tzdtH)(2)I](+)[I(3)](-).2I(2) (2) and the charge transfer (CT) iodine complexes of formulae [(bztzdtH)I(2)] (3) and [(bztzdtH)I(2)].I(2) (4) (bztzdtH = 2-mercaptobenzothiazole) with "spoke" and extended "spoke" structures respectively, were tested for their oxidizing activity towards 3,5-di-tert-butylcatechol to 3,5-di-tert-butyl-o-benzoquinone.

A modified analytical procedure has been developed to test for 5 organic pollutants [benzophenone, 2 diisopropylnaphthalenes (DIPNs) {2,6-and 2,7-diisopropylnapthalene} and 2 hydrogenated terphenyls (HTPs) {m-terphenyl and o-terphenyl}] that can be found as residues in recycled cardboards intended for use as food packaging materials and to test for migration levels of these compounds in a food simulant (Tenax). A main objective was to develop a modified rapid and reliable method for the identification and quantification of these compounds at low concentrations. The method was based on ultrasound-assisted solvent extraction (UAE) followed by gas chromatography-mass spectrometry (GC-MS) analysis. The developed method was applied to analyze 3 commercially available recycled carton board food-packaging materials and also to study the potential migration of the 5 organic pollutants from these materials into Tenax to check if these recycled cardboards can be considered as suitable for use in direct contact with foodstuffs. The limits of detection (LODs) of standard solutions of the 5 compounds were determined at a signal-tonoise ratio of 3. The LODs and the limits of quantification (LOQs) of examined pollutants ranged between 0.005 to 0.5 mg/kg, and 0.1 to 1 mg/kg, respectively. The extremely low amounts of most contaminants that migrate from packaging materials to Tenax indicate that the recycled cardboards tested can be safely used for direct food contact applications.

The present work is part of a comprehensive study aiming to identify and quantify an array of harmful contaminants at very low concentrations in recycled paperboard materials intended for food contact applications. In this initial study, three commonly used extraction techniques were optimized and tested for their efficacy and accuracy in isolating 13 polycyclic aromatic hydrocarbons (PAHs) from three commercially available food packaging materials made from recycled paperboard. The techniques were Soxtec extraction (SE), ultrasound-assisted extraction (UAE), and headspace solid-phase microextraction (HS-SPME), followed by gas chromatography-mass spectrometry (GC/MS) analysis. The recoveries of all three methods were rather satisfactory; 10 out of 13 substances were recovered at rates between 70 and 124% using the SE method, 8 out of 13 substances were recovered at rates between 50 and 134% using the UAE method, and finally, 8 out of 13 substances were recovered at rates between 70 and 105% using the HS-SPME method. Regarding accuracy, the HS-SPME method gave the best results at 125 μg kg−1, as 7 out of 13 concentration values were within acceptable limits, while only five and four concentration values were within limits for the UAE and SE methods, respectively. Furthermore, the results of both the calculated RSD and HorRat values indicated that HS-SPME is more accurate for extracting PAHs than the other two methods.

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