Correlation coefficients (r) are shown for organochlorine concentrations (ng l −1 ) in snow and site elevation (m.a.s.l.) for the equation conc: ¼ ae b Elev: , where a and b are fitted constants. Asterisks show significance at P р 0:05, for 19 degrees of freedom. Sub-cooled liquid vapour pressures are included for pesticides at 20 ЊC (ref. 21) and PCBs at 25 ЊC (ref. 22). Published vapour pressures vary considerably, so these values represent mean reported values for all PCBs in that class. Ranges of published vapour pressures for each PCB category are shown in brackets.Only compounds with mean sample concentrations that were ten times higher than blanks were considered. † Present addresses:

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Spiro‐linkage of low molecular weight entities as a new structural concept for the design of new active materials for electroluminescent applications is presented. These spiro linked compounds result in nonpolymeric organic glasses with high thermal stability as can be derived from their high glass transition temperatures (Tg), and characterized by differential scanning calorimetry. Blue emitters based on spiro linked oligophenyles are presented. These compounds are soluble in common organic solvents and show high photoluminescence quantum efficiency in the solid state and high morphologic stability with glass transition temperatures up to 250°C. Charge transport materials based on spiro linked versions of 2‐(4‐biphenyl)‐5‐(4‐tert‐butylphenyl)‐1,3,4‐oxadiazole (PBD) for electron transport, and spiro linked versions of triphenyldiamin derivatives (TPD) for hole transport show improved morphologic properties with nearly unchanged electronic properties compared to the parent compounds. High quality amorphous films can be prepared with the spiro compounds by vapor deposition as well as by simple spin coating.