Abstract
Tetraalkyllead (R4Pb), trialkyllead (R3Pb(+)), and dialkyllead (R2Pb(++)) compounds were determined in rainwater collected at urban, semi-rural, and rural sites using gas chromatography/atomic absorption spectroscopy (GC/AAS). At sites in England, total organolead concentrations in the range of 10-928 ng Pb/l were found in rainwater and ratios of organic to inorganic lead were between < 0.1 and 20%. At a remote rural site on the west coast of Ireland, total organolead concentrations were in the range of 3-13 ng Pb/l. R3Pb(+) species containing mixed alkyl groups were also observed. At a semi-rural site in Southeast England, the deposition rate for total organic lead was 5.6 ng Pb/sq cm/yr. No consistent seasonal variation of alkyllead species or concentration was noted. Stability tests revealed that R4Pb compounds decompose quantitatively within 48 h to R3Pb(+) species in rainwater samples left in the field during sampling programs. R3Pb(+) and R2Pb(++) compounds were found to be very stable in rainwater samples left in the dark. (Author 's abstract)