An Environmental Friendly Procedure for Photometric Determination of Hypochlorite in Tap Water Employing a Miniaturized Multicommuted Flow Analysis Setup

Abstract

A photometric procedure for the determination of ClO− in tap water employing a miniaturized multicommuted flow analysis setup and an LED-based photometer is described. The analytical procedure was implemented using leucocrystal violet (LCV; 4,4′,4′′-methylidynetris (N,N-dimethylaniline), C25H31N3) as a chromogenic reagent. Solenoid micropumps employed for solutions propelling were assembled together with the photometer in order to compose a compact unit of small dimensions. After control variables optimization, the system was applied for the determination of ClO− in samples of tap water, and aiming accuracy assessment samples were also analyzed using an independent method. Applying the paired t-test between results obtained using both methods, no significant difference at the 95% confidence level was observed. Other useful features include low reagent consumption, 2.4 μg of LCV per determination, a linear response ranging from 0.02 up to 2.0 mg L−1 ClO−, a relative standard deviation of 1.0% (n = 11) for samples containing 0.2 mg L−1 ClO−, a detection limit of 6.0 μg L−1 ClO−, a sampling throughput of 84 determinations per hour, and a waste generation of 432 μL per determination.

Determinação fotométrica de sulfato e cloreto em coque de petróleo, molibdênio em plantas e zinco em águas empregando multicomutação com bomba de seringa

“…As medidas baseadas em espectroscopia eletrônica são geralmente feitas com o uso de espectrofotômetro, que é constituído de quatro partes; uma fonte de radiação que emite luz na faixa do UV-vis; um monocromador para seleção do comprimento de onda, o qual pode empregar filtros, lentes ópticas, redes de difração e prismas; um compartimento para amostra, geralmente uma cela de vidro ou de quartzo; e um sistema para detecção [48] [54,55], multicomutação em fluxo [56,57], sistemas de análises por injeção sequencial [58,59]. 4 -Vista do motor de passo.…”