Indicators were devised to classify air pollution monitoring sites according to the type of expected photochemical pollution. The indicators are based on measured ozone volume fractions, the most frequently monitored component of photochemical pollution, and in particular on two contributions: one due to the ratio of daily maximum-to-minimum ozone volume fractions and the other to observed peak values. The two contributions regarded as independent are logically connected by "and" and therefore mathematically combined by multiplication. The criterion of classification is mainly described by the mentioned ratio and incidences of ozone volume fractions exceeding the limit of 80 ppb. Twelve monitoring stations within the European network (Cooperative programme for monitoring and evaluation of long-range transmission of air pollutants in Europe, EMEP) were classified according to this indicator predicting what ozone levels can be expected at the particular sites during the growth season (April through September) into three groups: clean, medium, and polluted, based on the data for the 7 years (1997 to 2003).
Natural polymers, humic acid and lignins, were investigated by laser desorption (LD) Fourier transform mass spectrometry. In the vapor phase under LD conditions only positive ions of humic acid were observed up to m/z 700. Under the same conditions all the lignins investigated prefer to form negative ions of the individual oligomers at well-defined mass spacings and with a distribution from m/z several hundred to 3OOO. Three sequences with Am-444 confirm the existence of stable trimer building blocks in the coniferous lignins.
The several types of lignin samples (birch, spruce and 'model' lignin) were investigated by laser desorption (LD) Fourier-transform mass spectrometry. In the vapor phase under LD conditions, the investigated lignins prefer to form negative ions of the individual oligomers at well defined mass spacings. Three sequences with Am = 444 confirm the existence of the stable trimer building blocks in the spruce and 'model' lignin.
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