Determination of trace mercury(II) in wastewater using on-line flow injection spectrophotometry coupled with supported liquid membrane enrichment

An on-line flow-injection spectrophotometric method coupled with supported liquid membrane enrichment was developed to determine trace Hg(II) in water. Tributyl phosphate (TBP) dissolved in kerosene was used as the flow carrier in a supported liquid membrane extraction system. The effect of various parameters on Hg(II) measurement was investigated. The optimum conditions were determined as 20% TBP in the membrane phase, 0.02 mol L-1 NaOH in the accepting phase, 0.8 mol L-1 HCl in the feeding phase, 0.2 mu m PTFE membrane in the enrichment process, and 20 min enrichment time. Under these optimum conditions, the linear range for Hg(II) measurement was from 0.2 to 30 mu g L-1 with a detection limit of 0.06 mu g L-1. Additionally, we demonstrated that this system can be used to determine trace Hg(II) in wastewater.