Application of PY/GC/MS to the Development of a Model for Quality Prediction of PE Pipes.

Polyethylene pipes for water transportation are attractive for technical and economic reasons. However, premature ruptures due to poor quality of the production process or the raw material cast a shadow on this material. The application of PY/GC/MS to the molecular charcterization of polyethylene water pipes is described. The statistical treatment of pyrolysis results allowed to differentiate various groups of pipes. A comparison with conventional polyethylene physical tests is provided. PY/GC/MS showed potential as a tool to estimate pipe quality and hence its resistance against ruptures caused by pressure stress

Rapid Analysis of Tile Industry Gaseous Emissions by Ion Mobility Spectrometry and Comparison with Solid Phase Micro Exctraction / Gas Chromatography / Mass Spectrometry

The present paper reports on a rapid analysis of gaseous emissions from ceramic industry, using Ion Mobility Spectrometry (IMS) as a means for on-site monitoring of Volatile Organic Compounds (VOC) produced during tile baking. IMS was calibrated with a set of reference compounds (i.e. Ethyl Acetate, Ethanol, Ethylene Glycol, Diethylene glycol, Acetaldehyde, Formaldehyde, 2-Methyl-1,3-Dioxolane, 2,2-Dimethyl-1,3-Dioxolane, 1,3-Dioxolane, 1,4-Dioxane, Benzene, Toluene, Cyclohexane, Acetone, Acetic Acid) via air-flow permeation. Secondly, the technique was tested on a laboratory-scale kiln and tiles prepared with selected glycol-, and resin-based additives. Finally, IMS was applied to emissions from two industries in the Modena (Italy) ceramic area. The results of all experimental phases were compared to those obtained by Solid Phase Micro-Extraction/Gas Chromatography/Mass Spectrometry (SPME/GC/MS). The techniques produced similar results and IMS showed potential as a real-time monitoring device for quality assessment in ceramic industry emissions. IMS spectra, SPME/GC/MS data, relationship between additives/baking conditions and produced VOC, and advantages and limitations of both techniques will be discussed

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\u20132 ng/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 O3/ClO2 to observe the effect of disinfection on NAs\u2019 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 10 ng/L set by the California Department of Public Health. Because dermal adsorption has been recently indicated as a new contamination route of exposure toNAs 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 50 ng/L, likely as a disinfection by-product from the amino acid precursor proline, a main constituent of skin collagen

Determination of Imidacloprid and metabolites by liquid chromatography with an electrochemical detector and post column photochemical reactor

A procedure for the determination of Imidacloprid and its main metabolites was set up by means of liquid chromatography with an electrochemical detector and post-column photochemical reactor (LC-h-ED). Sample clean-up was developed for bees, filter paper and maize leaves. Chromatographic conditions were based on a reversed-phase C-18 column operated by phosphate buffer 50 mM/CH3CN (80/20, v/v) at pH 2.9. Determination of Imidacloprid and its metabolites was carried out at a potential of 800 mV after photoactivation at 254 nm. Compared to conventional techniques such as gas-chromatography/mass-spectrometry (GC/MS) or LC coupled to other detectors, the present method allows simultaneous trace-level determination of both Imidacloprid (0.6 ng ml-1) and its main metabolites (2.4 ng ml-1)

Rapid determination of methyl tert-butyl ether using dynamic headspace/ion mobility pectrometry.

Using an original, experimental set-up named Dynamic Headspace/IMS (DHS/IMS), ppb levels of methyl tert-butyl ether (MTBE), a gasoline additive and environmental pollutant, were determined in drinking and ground water. A portable IMS (Bruker, Raid-1 model) was connected to the outlet of a Drechsel bottle containing 100 ml of water-based sample. Automatically activated to sample air, the IMS built-in pump was used to produce a continuous and gentle air flow bubbling through the water-based sample. This allowed volatile MTBE to be isolated and transferred into the Drechsel headspace and then into the IMS. Analyses of reference solutions and real samples resulted in MTBE detection limits of 20 ppb, calibration curves in the 20 – 200 ppb range, and relative standard deviations of 4.7% and 8.4%, respectively, for inter- and intra-day reproducibility tests. Detection limits were further improved to 0.5 ppb by means of a Tenax trap cooled with liquid nitrogen placed between the sample bottle and the IMS. Overall, DHS/IMS could well become a simple, cost-effective tool for the rapid, on-line analysis of volatile organic compounds in water