Determination of the speciation of organolead compounds in airborne particulate matter by gas chromatography–inductively coupled plasma mass spectrometry Original Research Article

The speciation of organolead compounds in airborne particulate matter was determined by gas chromatography–inductively coupled plasma mass spectrometry. The analytes were extracted from the sample using 0.5 M acetic acid in methanol. The ionic organolead compounds were extracted into hexane using diethydithiocarbamate at pH 9 in the presence of EDTA to complex inorganic Pb. Derivatisation of the organolead species was performed with butylmagnesium chloride. Separation and detection of the butylated trimethyllead (TML), dimethyllead (DML), triethyllead (TEL) and diethyllead (DEL) was achieved. Detection limits, as Pb, were 3.2 fg for TML, 2.4 fg for DML, 1.8 fg for TEL and 9 fg for DEL for a 1 μl sample injection. Typical precision of repetitive injections was 1.5–4% using tetraethyllead (TrEL) as internal standard. The method proposed was validated by the determination of TML in the reference material CRM 605 and was applied to the analysis of airborne particulate matter in the atmosphere of the city of Oviedo. DML, DEL and methylethyllead (MEL) were detected at pg m−3 levels.