Airborne Aldehydes from Heating Rosin Core Solder and Liquid Rosin Flux to Soldering Temperatures

Abstract

Gas phase aldehydes produced from heating rosin core solder and liquid rosin flux to temperatures commonly used in soldering were trapped on sampling tubes containing XAD-2 resin coated with the derivatizing agent 2-hydroxymethylpiperidine. Analysis of the resulting oxazolidine derivatives was performed using gas chromatography/mass spectrometry (GC/MS). The observed aldehyde derivatives included formaldehyde, acetaldehyde, propionaldehyde, acrolein, isobutyraldehyde, butyraldehyde, isovaleraldehyde, valeraldehyde, furfural, hexanal, cyclohexane carboxaldehyde and other unidentified compounds likely to be aldehyde isomers. Formaldehyde, acetaldehyde, and benzaldehyde were detected in blank samples. By comparison with an internal standard, a sample produced by drawing air with contaminants derived by heating rosin core solder through a sampling tube contained levels of formaldehyde and acetaldehyde much greater than seen in sampling tube blanks. Benzaldehyde was not shown to be present at a significantly greater level in samples from heating rosin core solder than in blanks prepared using the same analysis protocol. The use of National Institute of Occupational Safety and Health (NIOSH) method 2539 extraction procedures produced blanks with levels of formaldehyde significantly lower than with a modified extraction method (methylene chloride, no sonication). The modified extraction method produced significantly lower benzaldehyde levels in blanks compared with the NIOSH extraction method using toluene and sonication of sampling sorbent tubes.