Analytical method for the simultaneous determination of polyfunctional amines used as monomers in the manufacture of food packaging materials.

This paper describes the development of a multi-analyte method for the determination of polyfunctional amines commonly used as monomers in the manufacture of food contact materials. Amines were analyzed by high-performance-liquid chromatography with diode-array detection (HPLC-DAD) after derivatization with dansyl chloride. The chromatographic analysis and the derivatization conditions were optimized. The proposed method was validated in terms of linearity, limits of detection and repeatabilities. The method showed an excellent sensitivity (LOD≤0.05 µg/mL) and appropriate repeatabilites (RSD (n=7)≤5%)). LC-MS/MS was used as a confirmatory technique. The stability of the amines in five food simulants (distilled water, 3% acetic acid, 10% ethanol, 50% ethanol and olive oil) under the most common testing conditions (10 days at 40 °C) was also studied. Results showed that amines had an acceptable stability in aqueous simulants but in the olive oil a loss of 100% was observed for all analytes.

HPLC analysis of organic acids using a novel stationary phase.

In the present work, a high performance liquid chromatographic method with UV detection for the separation of six organic acids including, tartaric, malic, acetic, lactic, citric and succinic is described. The separation was performed on a novel stationary phase TEKNOKROMA, Tr-010065 Mediterranea sea(18) (15 cm x 0.4 cm, i.d. 3 microm) and using water with a 0.1% (v/v) of formic acid as mobile phase. The advantages of this packing over a conventional octadecylsilane (ODS2) column are reported. The method was validated with respect to linearity, limits of detection and repeatabilities within day and between days and satisfactory results were obtained. The proposed method was applied for the determination of these compounds in commercially available white wines. The samples were injected directly without previous treatment. LC-MS was used as a confirmatory technique.

Determination of hexanal as indicator of the lipidic oxidation state in potato crisps using gas chromatography and high-performance liquid chromatography.

Hexanal (an oxidative state indicator) formed in the headspace of potato crisps during storage was evaluated using two different procedures. First, solid-phase microextraction, an innovative sampling preparation methodology was used. It consisted on the absorption of analytes directly from samples and subsequent thermal desorption on the gas chromatograph (GC) injector. Then, a reversed-phase high-performance liquid chromatographic technique (HPLC) was employed to quantify hexanal in the form of 2,4-dinitrophenylhydrazone derivative. Methods were evaluated in what concerns to validation parameters such as linearity, repeatibility and detection limit. GC (LOD = 1 ng/ml) method resulted in more sensitive method than HPLC (LOD = 9 ng/ml). The most suitable technique for hexanal measurement was selected.