Sensitive determination of dissolved sulfide in estuarine water by solid-phase extraction and high-performance liquid chromatography of methylene blue.
A sensitive method involving solid-phase extraction and HPLC analysis of methylene blue has been developed to measure nanomolar levels of dissolved sulfide in oxic surface waters. The procedure included 1) a preconcentration step, in which methylene blue generated from sulfide reaction with n,n-dimethyl-p-phenylenediamine in acidic conditions in the presence of ferric ion was absorbed onto Waters tC18 cartridge; and 2) a determination step, in which methylene blue was separated by HPLC in a gradient elution to minimize natural organic matter interference and detected by absorbance. The concentrations of the dissolved sulfide, quantified by standard addition, were about 2.1-4.7 nM in oxic surface waters from Galveston Bay, Texas.
Texas A&M University, Department of Oceanography, Galveston 77551, USA. tangd@tamug.tamu.edu
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D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D008751:Methylene Blue / Q000032:analysis*; D013440:Sulfides / Q000032:analysis*; D014867:Water / Q000737:chemistry*
D013440:Sulfides; D014867:Water; D008751:Methylene Blue