Quantitative determination of dimethyl fumarate in silica gel by solid-phase microextraction/gas chromatography/mass spectrometry and ultrasound-assisted extraction/gas chromatography/mass spectrometry.

Dimethyl fumarate (DMF) is a chemical compound which has been added to silica gel bags used for preserving leather products during shipment. DMF has recently been singled out due to its ability to induce a number of medical problems in people which touch products contaminated by it. Its use as a biocide has been recently made illegal in Europe. Two different extraction techniques, namely ultrasound-assisted extraction (UAE) and solid-phase microextraction (SPME), both coupled with gas chromatography/mass spectrometry were applied to the quantitative determination of DMF in silica gel. Linearity of the methods, reproducibility and detection limits were determined. The two methods were applied to the quantification of DMF in thirty-four silica gel samples used as anti-mould agents in different leather products sold in Italy, and the obtained results were statistically compared.

The influence of pine volatile compounds on the olfactory response by Neodiprion sertifer (Geoffroy) females.

Females of the pine sawfly Neodiprion sertifer (Hymenoptera Diprionidae) usually avoid Pinus pinea trees as host plants. In contrast, this sawfly species is highly attracted by P. sylvestris and P. nigra trees. Here, we investigated which pine volatiles might mediate this behavior by in situ sampling experiments and olfactometer laboratory tests. Volatiles emitted from P. pinea, P. sylvestris, and P. nigra foliage were sampled by solid-phase microextraction (SPME). Analysis of these volatiles by coupled gaschromatography/mass spectrometry revealed that the relative amounts of the compounds emitted by the three species were significantly different. A discriminant analysis showed that the amounts of limonene and myrcene significantly contributed to the species-specific volatile patterns. Pinus pinea emitted higher relative amounts of limonene than the other pine species. Pinus sylvestris emitted the highest relative amounts of myrcene. When testing the response of N. sertifer females to these pine terpenoids in an olfactometer bioassay, a low amount of limonene was attractive, while a repellent effect was evident when higher amounts were used. The sawfly females showed no significant olfactory response to myrcene. These data suggest that low relative amounts of limonene have a significant function in attracting N. sertifer females, while high amounts might contribute to avoidance of a tree.

The use of tropical bromeliads (Tillandsia spp.) for monitoring atmospheric pollution in the town of Florence, Italy.

The results of an experiment with two species of epiphytic angiosperms (Tillandsia caput-medusae and T. bulbosa) for monitoring polycyclic aromatic hydrocarbons (PAHs) in the air of Florence, Italy, are presented. PAHs are compounds known to be dangerous because of their carcinogenic potential, and among cormophytes, tillands (monocotyledons equipped with peculiar, specialised, epidermal trichomes) are considered promising for air pollution biomonitoring. PAHs data were obtained using GC/MS analysis of plant extracts. Analytical data indicated an increasing trend in time of PAHs bioaccumulation. This result was compared with instrumentally recorded parameters such as meteorological (rain) and environmental ones (PM10), indicating that trichome-operated physical capture of aerial particles was prominent in PAHs bioaccumulation on tillands. SEM (scanning electron microscope) observations confirmed the role of the trichomes. This work indicates that tillands are particularly useful, low-cost biomonitoring organisms inside their area of distribution (all Latin American countries and southern USA) where these plants are easily available, but also wherever the climate allows them to survive.

Determination of nitrosamines in water by gas chromatography/chemical ionization/selective ion trapping mass spectrometry.

A gas chromatography/mass spectrometry (GC/MS) method for determination of nine N-nitrosamines (NAs) in water is described. Two ionization modes, electron impact (EI) and chemical ionization (CI) with methanol, as well as different ion analysis techniques, i.e. full scan, selected ion storage (SIS) and tandem mass spectrometry (MS/MS) were tested. Chemical ionization followed by SIS resulted the mass spectrometric method of choice, with detection limits in the range of 1-2ng/L. Solid Phase Extraction (SPE) with coconut charcoal cartridges was applied to extract NAs from real samples, according EPA Method 521. Drinking water samples were collected from seven surface- and two groundwater treatment plants. Three surface water treatment plants were sampled before and after addition of O(3)/ClO(2) to observe the effect of disinfection on NAs' formation. N-nitrosodiethylamine (NDEA), n-nitrosodipropylamine (NDPA), n-nitrosomorpholine (NMOR) and n-nitrosodibutylamine (NDBA) were found up to concentrations exceeding three times the risk level of 10ng/L set by the California Department of Public Health. Because dermal adsorption has been recently indicated as a new contamination route of exposure to NAs for people who practice swimming activity, water samples from five swimming pools in the Bologna (Italy) area were collected. N-nitrosopyrrolidine (NPYR) was detected in all samples at concentrations larger than 50ng/L, likely as a disinfection by-product from the amino acid precursor proline, a main constituent of skin collagen.

The use of tropical bromeliads (Tillandsia spp. ) for monitoring atmospheric pollution in the town of Florence, Italy

The results of an experiment with two species of epiphytic angiosperms (Tillandsia caput-medusae and T. bulbosa) for monitoring polycyclic aromatic hydrocarbons (PAHs) in the air of Florence, Italy, are presented. PAHs are compounds known to be dangerous because of their carcinogenic potential, and among cormophytes, tillands (monocotyledons equipped with peculiar, specialised, epidermal trichomes) are considered promising for air pollution biomonitoring. PAHs data were obtained using GC/MS analysis of plant extracts. Analytical data indicated an increasing trend in time of PAHs bioaccumulation. This result was compared with instrumentally recorded parameters such as meteorological (rain) and environmental ones (PM10), indicating that trichome-operated physical capture of aerial particles was prominent in PAHs bioaccumulation on tillands. SEM (scanning electron microscope) observations confirmed the role of the trichomes. This work indicates that tillands are particularly useful, low-cost biomonitoring organisms inside their area of distribution (all Latin American countries and southern USA) where these plants are easily available, but also wherever the climate allows them to survive.