caa a22 4500 463219686 CHVBK 20180405153208.0 cr unu---uuuuu 170326e20071001xx s 000 0 eng 10.1134/S1061934807100085 doi (NATIONALLICENCE)springer-10.1134/S1061934807100085 Spectrophotometric determination of thorium in food using 2-(2,5-disulfonic-4-methoxyphenylazo)-7-(2-hydroxyl-5-carboxylphenylazo)-1,8-dihydroxynaphthalene-3,6-disulfonic acid [Elektronische Daten] [S. Meng, M. Tian, Y. Liu, Y. Guo, Y. Fan] A new highly sensitive and selective chromogenic reagent, 2-(2,5-disulfonic-4-methoxyphenylazo)-7-(2-hydroxyl-5-carboxylphenylazo)-1,8-dihydroxynaphthalene-3,6-disulfonic acid (1), was synthesized and applied to the spectrophotometric determination of trace thorium. In 5 mL of a 6 M perchloric acid medium, which greatly increases the selectivity, thorium reacts with 1 to form a 1: 2 green complex, having a sensitive absorption peak at 670 nm. Under optimal conditions, Beer's law is obeyed over the range from 0 to 0.8 μg/mL Th(IV) and the apparent molar absorptivity is 2.09 × 105 L/mol cm. It is found that, uranium(VI), Ti(IV), heavy rare earths, and most of other common metal ions do not interfere. The method has been tested on the determination of thorium in food samples with satisfactory results. Pleiades Publishing, Ltd., 2007 Meng S. Department of Chemistry, Shanxi Datong University, 037009, Datong, China aut Tian M. Department of Chemistry, Shanxi Datong University, 037009, Datong, China aut Liu Y. Department of Chemistry, Shanxi Datong University, 037009, Datong, China aut Guo Y. Department of Chemistry, Shanxi Datong University, 037009, Datong, China aut Fan Y. Department of Chemistry, Shanxi Datong University, 037009, Datong, China aut Journal of Analytical Chemistry Nauka/Interperiodica 62/10(2007-10-01), 946-950 1061-9348 62:10<946 2007 62 10809 https://doi.org/10.1134/S1061934807100085 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1134/S1061934807100085 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Meng S. Department of Chemistry, Shanxi Datong University, 037009, Datong, China aut NATIONALLICENCE 700 1- Tian M. Department of Chemistry, Shanxi Datong University, 037009, Datong, China aut NATIONALLICENCE 700 1- Liu Y. Department of Chemistry, Shanxi Datong University, 037009, Datong, China aut NATIONALLICENCE 700 1- Guo Y. Department of Chemistry, Shanxi Datong University, 037009, Datong, China aut NATIONALLICENCE 700 1- Fan Y. Department of Chemistry, Shanxi Datong University, 037009, Datong, China aut NATIONALLICENCE 773 0- Journal of Analytical Chemistry Nauka/Interperiodica 62/10(2007-10-01), 946-950 1061-9348 62:10<946 2007 62 10809 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer