Furosine as a pasta quality marker: evaluation by an innovative and fast chromatographic approach.

A fast and simple high-performance liquid chromatography method suitable for determining furosine level in heat-treated food samples was developed. The analysis of furosine was performed by a novel mixed-mode column that provides multiple and simultaneous retention mechanisms including cation-exchange, anion-exchange, reversed-phase, or hydrophilic interaction. Each retention mechanism could be independently controlled by setting chromatographic conditions. Adequate retention and selectivity of polar charged furosine were achieved by adjusting mobile phase pH, buffer concentration, organic content, and ionic strength. The optimized method was successfully applied to determinate furosine in durum wheat semolina pasta samples. Furosine level in pasta may be used as a reliable marker of health and nutritional damage occurring during pasta manufacture. Indeed, a low content of furosine is generally related to high nutritional quality of food and application of mild heat treatments. A wide range of dry pasta samples, collected from both supermarkets (large-scale retail trade) and shops selling local products, were analyzed. Variable amounts of furosine, ranging from 107 to 506 mg/100 g of protein, were found in pasta samples. The proposed method allows to discriminate products submitted to different time-temperature conditions during the drying process. At the same time, it may be used to highlight potential label fraud.

Direct immersion-solid phase microextraction for the determination of chlorinated pesticide residues in tomatoes by gas chromatography with an electron capture detector.

The use of pesticides in agriculture has grown dramatically over the last decades. Environmental exposure of humans to agrochemicals is common and results in both acute and chronic health effects. In this study, direct immersion-solid phase microextraction (SPME) was coupled with electron capture detection for trace determination of 19 chlorinated pesticides in tomato samples, using a 100 pm polydimethylsiloxane fiber. The experimental parameters extraction time, extraction temperature, stirring, and salting out were evaluated and optimized. The LODs ranged from 0.5 to 8 microg/kg, and the LOQs from 5 to 30 microg/kg. A linear response was confirmed by correlation coefficients ranging from 0.97 to 0.9985. The developed method was tested by analyzing real samples purchased within the network of Italian distribution. The samples were found to be free from detectable residues of the studied pesticides. SPME has been shown to be a fast extraction technique that has several advantages such as solvent-free extraction, simplicity, and compatibility with the chromatographic analytical system.

Development of a headspace-solid phase microextraction-gas chromatography method to determine organohalogen contamination in drinking water.

The formation of organohalogen compounds in waters treated by chlorination has drawn increasing scientific attention due to the potentially hazardous health effects of this class of substances. Today, chlorination is the most widely used technology for civil water disinfection. In this study, headspace-solid phase microextraction coupled with GC-electron capture detector was used to determine organohalogen compounds in drinking water sampled from aqueducts and artesian wells in Italy. Experimental parameters, such as sample volume, stirring, salting out, extraction temperature, and extraction time, were evaluated and optimized. The LODs ranged from 1 to 10 ng/L and LOQs from 5 to 50 ng/L. A linear response was confirmed by correlation coefficients ranging from 0.9443 to 0.9999. Quantifiable organohalogen residues were found in 11 water samples, with concentration up to 11.3 +/- 0.5 microg/L for the sum of all trihalomethanes and 0.66 +/- 0.03 microg/L for the sum of trichloroethylene and tetrachloroethylene. These concentrations are lower than the current regulatory limits in Italy.

Multiresidue method for the determination of organophosphorus pesticides in cereal matrixes.

Our research was focused on a preliminary comparison of three cleanup procedures for the determination of 26 organophosphorus (OP) pesticide residues in cereal matrixes. The aim of the study was to reduce the analytical problems associated with the presence of high-molecular-weight compounds in these matrixes in order to improve the efficiency of the chromatographic separation. The method was based on the extraction of OP pesticides from the samples with the use of petroleum ether, acetone, and dichloromethane, and on three different cleanup procedures, followed by GC identification. The first procedure was carried out with a multicartridge system; the second procedure consisted of a low-temperature lipid precipitation; for the third procedure, acid and neutral alumina were used for cleanup of the extract. The use of deactivated acidic alumina as the adsorbent medium and the use of n-hexane-dichloromethane-ethyl acetate (6 + 3 + 1, v/v/v) as the eluting system were preferred. After purification, the residue was injected into a gas chromatograph for separation followed by nitrogen-phosphorus detection; the identities of the OP pesticides in positive samples were confirmed by GC/MS. The proposed method could be extended to the determination of other OP pesticides in various food matrixes in routine analysis.