Determination of trace calcium by solid substrate-room temperature phosphorimetry

Abstract A new method for the determination of trace calcium by solid substrate-room temperature phosphorimetry is established. It is based on the fact that chromeazurols azurol S -phenanthroline-NaCMC (CAS-phen-NaCMC) system can emit strong and stable room temperature phosphorescence (RTP) on the solid substrate in the filter paper. Ca 2+ and phenanthroline can form complex ion Ca(phen) 3 2+ , which will form complex [Ca(phen) 3 (CAS) 2 ] with CAS. In the result, the number of CAS molecules in each spot increased, causing sharp increase of the RTP signal of the CAS-phen-NaCMC system.