Coupling of SPME with MCC/UV-IMS as a tool for rapid on-site detection of groundwater and surface water contamination.

The combination of headspace solid phase microextraction (HS-SPME) [1] with fast chromatographic pre-separation by means of multi-capillary columns (MCC) coupled to an ion mobility spectrometer equipped with a 10.6 eV photoionisation source was applied to rapid on-site monitoring of ground and surface water contaminations. Under field conditions, water contaminants were directly detectable down to the upper microg/L range.

Application of infrared spectroscopy to monitoring gas insulated high-voltage equipment: electrode material-dependent SF(6) decomposition.

Sulfur hexafluoride is a chemically inert gas which is used in gas insulated substations (GIS) and other high-voltage equipment, leading to a significant enhancement of apparatus lifetime and reductions in installation size and maintenance requirements compared to conventional air insulated substations. However, component failures due to aging of the gas through electrical discharges may occur, and on-site monitoring for risk assessment is needed. Infrared spectroscopy was used for the analysis of gaseous by-products generated from electrical discharges in sulfur hexafluoride gas.

Phase transfer and freezing processes investigated on acoustically levitated aqueous droplets.

An acoustic trap was designed and constructed to investigate, on a microscale, physicochemical processes relevant to the troposphere, mainly focusing on the temperature range below 0 degrees C. Droplets ranging from 0.5 nL to 4 microliter (0.

On-site characterization of humic-rich hydrocolloids and their metal loading by means of mobile size-fractionation and exchange techniques.

Humic-rich hydrocolloids and their metal loading in selected German bog-waters have been characterized by a novel on-site approach. By use of an on-line multistage ultrafiltration (MST-UF) unit equipped with conventional polyethersulfone (PES)-based flat membranes (nominal cut-off 0.45, 0.

Determination of acrylic acid in air by using diffusion denuder tubes combined with HPLC technique.

A procedure for the determination of atmospheric acrylic acid in air at the microgram m-3 to mg m-3 level is described. Diffusion-based sampling, designed to discriminate gaseous analytes from their particulate counterparts, has been used. Acrylic acid is collected with an efficiency of > 98% in tubular denuders coated with sodium hydroxide-barium hydroxide-hydroquinone monomethyl ether, and analyzed by high performance liquid chromatography with UV absorbance detection.

Degradation of alpha-pinene on Tenax during sample storage: effects of daylight radiation and temperature.

The behavior of alpha-pinene sampled on adsorption cartridges filled with Tenax TA has been investigated in relation to different storage conditions, focusing on daylight radiation and temperature. After sampling, the respective cartridges containing the terpene were placed in sunlight on the windowsill for up to 1 month. Corresponding samples have been wrapped in aluminum foil to prevent the influence of daylight radiation.

Determination of soluble and insoluble nickel compounds in airborne particulate matter by graphite furnace atomic absorption spectrometry and inductively coupled plasma mass spectrometry.

An extraction procedure for the determination of soluble and insoluble nickel and its compounds in ambient air dust was investigated employing a special device for the generation of test aerosols and using water-soluble NiCl2, partly water-soluble NiCO3 and water-insoluble NiO as model compounds. Additionally, results of the separation and determination of different nickel species down to some ng/m3 in ambient aerosols are discussed. The extraction was carried out with a solution containing 0.

Application of gas chromatography-cryocondensation-Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry to the identification of gas phase reaction products from the alpha-pinene/ozone reaction.

The gas phase reaction of alpha-pinene with the atmospheric oxidant ozone was investigated by using the capabilities of both gas chromatography-cryocondensation-Fourier transform infrared spectroscopy (GC-FT-IR) and gas chromatography-mass spectrometry (GC-MS), for the identification of the reaction products formed. The reaction was carried out in a flow reaction chamber from where the compounds were sampled on Tenax-containing adsorption cartridges. The reaction mixture was injected onto the column after thermodesorption and analyzed using both GC-IR and GC-MS.

Mutagenic properties of 1,2,3,4-tetrahydronaphthaline-1-hydroperoxide, a model compound for organic peroxides in Diesel exhaust.

The genotoxicity of the organic peroxide 1,2,3,4-tetrahydronaphthaline-1-hydroperoxide (or tetraline-1-hydroperoxide, THP) was investigated in the Ames assay without a metabolic activating system using Salmonella typhimurium strains TA 98, TA 100, and TA 102. THP served as a model compound for higher organic peroxides, which can arise from autoxidation of hydrocarbons, e.g.

Investigation and analytical application of the sulphide-hypobromite chemiluminescence reaction.

The results of an investigation of the sensitized and non-sensitized chemiluminescence reaction between sulphide and hypobromite in alkaline solution are presented. The reaction can be used for the determination of traces of sulphide at concentrations above 5 x 10(-8)M. For this purpose a special flow system is employed which includes coulometric generation of reagent, and photon-counting.

Application of competitive reaction systems to catalytic kinetic analysis-determination of phosphate.

A technique is described for the determination of catalytically active substances, in which a slow catalysed reaction is coupled to a fast competitive reaction. One reactant, which at the same time serves as the indicator substance, is removed by the slow reaction as well as by the competitor added to the system from outside. Under suitable conditions the time for the complete removal of the indicator substance is dependent only on the rate of the catalysed reaction and consequently on the catalyst concentration.

Radiochemical separations by the ring-oven technique-IV The system (144)Ce/(144)Pr.

By using filter papers impregnated with a manganese oxide hydrate having an average oxidation number of + 3, it is possible to separate (144)Pr from (144)Ce rapidly by the ring-oven technique. With 0.06-0.

Kinetische bestimmung von molybdän unter verwendung eines potentiostaten.

A kinetic method is described for the determination of molybdenum by its catalytic effect on the peroxide-iodide reaction. The reaction rate is kept constant by adding iodide at the same rate as it is being consumed, the concentration being kept constant by a potentiostat. The rate of the addition of iodide is then proportional to the molybdenum concentration.