Photometric Sensing of Active Chlorine, Total Chlorine, and pH on a Microfluidic Chip for Online Swimming Pool Monitoring

A microfluidic sensor was studied for the photometric detection of active chlorine, total chlorine, and pH in swimming pool samples. The sensor consisted of a four-layer borosilicate glass chip, containing a microchannel network and a 2.2 mm path length, 1.7 mL optical cell. The chip was optimised to measure the bleaching of methyl orange and spectral changes in phenol red for quantitative chlorine (active and total) and pH measurements that were suited to swimming pool monitoring. Reagent consumption (60 mL per measurement) was minimised to allow for maintenance-free operation over a nominal summer season (3 months) with minimal waste. The chip was tested using samples from 12 domestic, public, and commercial swimming pools (indoor and outdoor), with results that compare favourably with commercial products (test strips and the N,N’-diethyl-p-phenylenediamine (DPD) method), precision pH electrodes, and iodometric titration.

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A new spectroelectrochemical cell with a long optical path length for redox studies of phthalocyanines

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424606000478 ◽

2006 ◽

Vol 10 (09) ◽

pp. 1125-1131 ◽

Cited By ~ 5

Author(s):

Hiroaki Isago

Keyword(s):

Path Length ◽

Reference Electrode ◽

Optical Path Length ◽

Optical Path ◽

Auxiliary Electrode ◽

Platinum Foil ◽

Optical Cell ◽

Spectral Changes ◽

Solution Interface ◽

Propagation Axis

A new spectroelectrochemical cell with a long optical path length has been fabricated for redox studies of phthalocyanines, where the propagation axis of the optical beam is parallel to the electrode/solution interface. It is composed of a homemade Teflon block that fits inside a standard 1 cm quartz optical-cell, equipped with a platinum-foil working electrode, a platinum-wire auxiliary electrode, and a AgCl -coated silver-wire reference electrode. This new cell makes it much easier to acquire spectral data for dilute solutions containing species, like phthalocyanines, that have limited solubility in common organic solvents or that strongly aggregate in solution. As examples, electrolyses of the [tetra(tert-butyl)phthalocyaninato]zinc(II) complex and its cobalt(II) analogue were performed to monitor spectral changes ascribable to phthalocyanine-ligand-centered oxidation and metal-centered reduction, respectively. Spectra of unaggregated electrogenerated species were successfully observed.

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Mise Au Point D’un Protocole De Sterilisation D’explants Nodaux D’alchornea Cordifolia Avec De L’acide Triclororoisocyanurique

European Scientific Journal ESJ ◽

10.19044/esj.2017.v13n15p274 ◽

2017 ◽

Vol 13 (15) ◽

pp. 274

Author(s):

Aurélien Mokea-Niaty ◽

Samson Daudet Medza Mve ◽

Alexis Nicaise Lepengue ◽

Antoine Mitte Mbeang Beyeme ◽

Christian Moupela ◽

...

Keyword(s):

In Vitro Culture ◽

Broad Spectrum ◽

Natural Environment ◽

Room Temperature ◽

Swimming Pool ◽

Nodal Explants ◽

Active Chlorine ◽

Running Water ◽

Trichloroisocyanuric Acid

Trichloroisocyanuric acid is a swimming pool disinfectant and is readily accessible. As a result, there is the need to use it as a substitute for conventional disinfectants in in vitro culture. Nodal explants of Alchornea cordifolia, harvested in a natural environment, have been rinsed abundantly with Dettol under running water. Then it was soaked in Talo Plus (550 g/l carbendazim and 100 g/l Chlorothalonil) at 5 ml/liter, which is a broad spectrum fungicide. After then, it was immersed in 70% alcohol for 10 minutes before being soaked in different solutions of trichloroisocyanuric acid to: 6, 4, 3, 2, 1, 0.3, 0.1, and 0.08%. The explants were disinfected completely of all contaminating bacterial and fungal exogenous. This was after a treatment in solutions of acidic trichloroisocyanurique of 6 to 0.08%. The results showed that the losses of active chlorine remained low during storage at temperatures of 4 to 18 ± 2°C. They reach only 5.29% after 72 hours. At room temperature of 27 ± 2 ° C, these losses are more than 30% after three days. Concentrations of 0.1 to 0.3% are effective for the disinfection of explants. This protocol of explants disinfection in vitro culture could therefore be advantageously substituted using the hypochlorite of calcium or the chloride of mercury.

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