Analytical Sciences


Abstract − Analytical Sciences, 15(9), 847 (1999).

In-Line Concentration on Chitosan and the Use of 2,2'-Dipyridyl-2-Pyridylhydrazone for the Flow-Injection Spectrophotometric Determination of Lead
Adriana G. LISTA and Beatriz S. Fernandez BAND *
Department of Chemistry and Chemical Engineering, Universidad Nacional del Sur, Av. Alem 1253-8000, Bahia Blanca, Argentine
A flow-injection system with spectrophotometric detection involving the in-line concentration was developed for lead determination in natural water samples. Lead concentration was carried out in a mini-column packed with novel stuff chitosan, and sorption occurred at pH=6 - 9. The amount of lead flowing through the chitosan was controlled by time, the CTAB surfactant was passed through a mini-column and a 0.2 M NaOH stream was used as the eluent. The eluted lead merged with 2,2'-dipyridyl-2-pyridylhydrazone (DPPH) reagent synthesised in the author's lab and with a borate solution; complex formation took place at pH 11 - 12 inside a following reactor and monitoring was carried out at 468 nm. The detection limit was 0.13 mg l-1 and, the sample throughput was 25 h-1. The accuracy was assessed by running spiked river-water samples. (Keywords: Lead(II), preconcentration, spectrophotometry, flow analysis, chitosan)