caa a22 4500 467995338 CHVBK 20180323112555.0 cr unu---uuuuu 170328e19900701xx s 000 0 eng 10.1007/BF01244767 doi (NATIONALLICENCE)springer-10.1007/BF01244767 Fluorimetric determination of calcium by ion-pair extraction with cryptand 2.2.1 and eosin [Elektronische Daten] [Domingo Gomis, Elena García, Enrique Alonso, Pilar Abrodo] A fluorimetric study on the extraction of calcium into 1,2-dichloroethane as an ion-pair, formed between the cryptand 2.2.1-calcium complex and the eosinate anion, is described. Optimum conditions for extraction are established and a new fluorimetric determination of ultratraces of calcium is proposed. A linear working range from 1.5 ng ml−1 (detection limit) to 100 ng ml−1 of calcium and a relative standard deviation of ± 2.9% at the 70 ng ml−1 level are obtained. The equilibrium constants involved in the extraction process have been calculated and refined by the Letagrop-DISTR program. The proposed method has been tested for the direct determination of calcium in sugars. Springer-Verlag, 1990 calcium nationallicence cryptand 2.2.1 nationallicence fluorimetric determination nationallicence ion-pair extraction nationallicence Gomis Domingo Departamento de Química Física y Analítica, Facultad de Química, Universidad de Oviedo, E-33006, Oviedo, Spain aut García Elena Departamento de Química Física y Analítica, Facultad de Química, Universidad de Oviedo, E-33006, Oviedo, Spain aut Alonso Enrique Departamento de Química Física y Analítica, Facultad de Química, Universidad de Oviedo, E-33006, Oviedo, Spain aut Abrodo Pilar Departamento de Química Física y Analítica, Facultad de Química, Universidad de Oviedo, E-33006, Oviedo, Spain aut Microchimica Acta Springer-Verlag 102/4-6(1990-07-01), 259-269 0026-3672 102:4-6<259 1990 102 604 https://doi.org/10.1007/BF01244767 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01244767 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Gomis Domingo Departamento de Química Física y Analítica, Facultad de Química, Universidad de Oviedo, E-33006, Oviedo, Spain aut NATIONALLICENCE 700 1- García Elena Departamento de Química Física y Analítica, Facultad de Química, Universidad de Oviedo, E-33006, Oviedo, Spain aut NATIONALLICENCE 700 1- Alonso Enrique Departamento de Química Física y Analítica, Facultad de Química, Universidad de Oviedo, E-33006, Oviedo, Spain aut NATIONALLICENCE 700 1- Abrodo Pilar Departamento de Química Física y Analítica, Facultad de Química, Universidad de Oviedo, E-33006, Oviedo, Spain aut NATIONALLICENCE 773 0- Microchimica Acta Springer-Verlag 102/4-6(1990-07-01), 259-269 0026-3672 102:4-6<259 1990 102 604 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer