Determination of Trace Silver by Solid Substrate Room Temperature Phosphorescence Quenching Method

Luminescent particles of lead carboxymethyl cellulose(Pb(CMC)2) containing salicyl fluorones(THBF),Pb(CMC)2-THBF were synthesized by the sol-gel method,using sodium carboxymethyl cellulose(NaCMC) as precursor and Pb2+ as precipitant.Pb(CMC)2-THBF can emit the intense and stable solid substrate room temperature phosphorescence(SS-RTP) on filter paper.And EDTA can chelate Pb2+ in Pb(CMC)2-THBF,causing it decompose into aqueous soluble components PbY2–,CMC– and THBF,which can react with Ag+ to form Ag(CMC)2-THBF,causing the decrease of phosphorescence intensity.Based on the facts above,a new method for the determination of trace silver by SS-RTP quenching method was established.This method has been applied to the determination of trace silver in human hair and tea sample with satisfactory results.The mechanism of SS-RTP emission is also discussed.