Abstract
Sulfide ion is known to be unstable in dilute alkaline solution, rendering this medium unsuitable for collection of hydrogen sulfide. In this study it is shown that the presence of Cu2+, strongly influences the loss of sulfide from alkaline solution. Further, it is demonstrated that addition of triethanolamine (TEA) and ethylenediaminetetraacetic acid (EDTA) greatly reduces this effect and, consequently, has potential as a collection medium for airborne hydrogen sulfide. Hydrogen sulfide contaminated air was drawn through solutions of 0.1 M NaOH+1% TEA+0.1% EDTA. The collection efficiency of the solution, as determined by placing two impingers in series, is greater than 95%. Losses of absorbed hydrogen sulfide during storage were less than 5% at room temperature over 10 days. The solutions were used to sample atmospheres containing known concentrations of hydrogen sulfide. Recoveries of 96%–112% were obtained over the concentration range 1.4–21.0 mg/m3.