Man, nutrition and mobility: a comparison of teeth and bone from the Medieval era and the present from Pb and Sr isotopes.

Naturally occurring isotopic systems, such as strontium (Sr) and lead (Pb), are very useful for characterizing different sources and to produce background information. Norwegian teeth from the Medieval era have 206Pb/204Pb ratios between 18.8 and 18.2, in comparison with present day ratios of between 18.0 and 17.6 showing the impact of Pb from modern industrialization and from traffic. Sr analyses of Medieval teeth show that an individual living in a coastal town on the west coast of Norway can easily be distinguished from one in a rural area at that time. The Sr signature shows that Medieval people lived on local products while present people to a greater degree live on imported or domestic industrially processed food. Medieval and modern teeth from one site give similar Pb signatures and concentrations indicating no increase in pollution over time. However, the impact of industrial pollution can be seen from Pb analyses on contemporary teeth, so that the method can be used to monitor emission of heavy metals from local industry. Whilst the Pb and Sr natural isotopic systems individually provide valuable information, a combination of the two techniques is a very powerful tool in environmental and archaeological research.

Sample introduction valve used in ICP-AES for faster analysis.

A twin six-port valve with two sample loops was installed between the autosampler and the nebuliser of a simultaneous inductively coupled plasma-atomic emission spectrometer. The valve was mounted close to the nebuliser inlet so that the time required for the sample to enter from the loop to the nebulizer was less than 0.5 s. The content of one loop was introduced to the nebulizer using a peristalic pump, whilst a second loop was filed with the next sample using a second peristaltic pump. The washout time was in this manner reduced by 20 s per analysis and the hourly sampling rate was increased from 90 to 180 in the measurements described.

Organic air pollutants in an aluminum reduction plant.

The content of organic pollutants, other than polycyclic aromatic hydrocarbons (PAH), was determined in air samples collected in the potroom of a Söderberg aluminum reduction plant. The neutral and the basic fractions of the sample extract were analysed, and aza-arenes, carbazoles, 1-nitropyrene and quinones as well as aromatic aldehydes and ketones were identified by gas chromatography and mass spectrometry (GC/MS). Selected compounds were quantified and the results indicate that the concentrations in the potroom atmosphere are high. Some of the identified compounds are known to have adverse health effects, and should therefore be included whenever air quality studies are carried out inside or near aluminum plants.

High pressure liquid chromatographic determination of patulin in apple juice.

Patulin was extracted from apple juice with ethyl acetate and the extract was purified by elution from a silica gel column with ethyl acetate-toluene. The eluate was concentrated, and patulin was determined by reverse phase high pressure liquid chromatography using a 25 cm Partisil-10 ODS column. The lower detection limit was 1 microgram/L and the mean recovery of patulin added to apple juice was 82.6 +/- 2.8 %. The patulin content ranged from less than 1 to 220 microgram/L for the 140 samples analyzed.