University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Website: @unf

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Classification: Water -> swimming pool

Citations 3

"Flow Injection Spectrophotometric Determination Of Hydrogen Peroxide Using A Crude Extract Of Zucchini As A Source Of Peroxidase"
Analyst 1998 Volume 123, Issue 9 Pages 1809-1812
Iolanda da Cruz Vieira and Orlando Fatibello-Filho

Abstract: A flow injection (FI) spectrophotometric procedure is presented for determining H2O2 for pharmaceutical use and in swimming pool water samples. Crude extracts of several vegetables such as peach, yam, manioc, artichoke, sweet potato, turnip, horseradish and zucchini were studied as the source of peroxidase (donor: H2O2 oxidoreductase, POD; EC Of these, a zucchini crude ext. gave highest specific activity and was used directly as the carrier solution This enzyme catalyzes the oxidation of guaiacol in the presence of H2O2 to tetraguaiacol, which shows strong absorbance at 470 nm. For the optimum extraction conditions found, the peroxidase activity in the crude ext. did not vary for at least 5 mo when stored at 4°C and decreased by only 2-3% during an 8 h working period at 25°C. The recovery of H2O2 from two samples ranged from 97.8 to 103.0% and a rectilinear calibration curve for H2O2 concentration. from 1.6 x 10^-5 to 6.6 x 10^-4 mol L-1 was obtained. A detection limit of 2.1 x 10^-6 mol L-1 and a sample throughput of 32 h-1 were attained. The relative standard deviations were <0.2% for H2O2 solutions containing 2.0 x 10^-4 and 4.0 x 10^-4 mol L-1 (n = 10) and a paired t-test showed that all results obtained for water samples using this FI procedure and permanganate titration agreed at the 95% confidence level.
Hydrogen peroxide Spectrophotometry Indirect Enzyme Optimization Method comparison

"Potentiometric Gas Sensor For The Determination Of Free Chlorine In Static Or Flow Injection Analysis Systems"
Anal. Chem. 1986 Volume 58, Issue 3 Pages 650-653
J. F. Coetzee and C. Gunaratna

Abstract: A potentiometric Cl sensor was constructed from an Orion Model 95-10 ammonia electrode body by using a Gore-Tex PTFE, polyethylene or polypropylene membrane (0.45 µm). The Cl diffused from the analyte solution through the membrane and reacted with the internal buffer (0.1 M Na2SO4 - NaHSO4 of pH 4.5) to give Cl- which was measured by a silver - AgCl electrode. Results are presented for both static and flow injection systems. The free Cl determined by the latter system in swimming-pool water was 1.12 ± 0.02 ppm, which agreed well with the result obtained iodometrically. The static method gave a lower detection limit of 5 µM-Cl with longer recovery and response times.
Chlorine Electrode Potentiometry Sensor Method comparison

"Flow Injection Spectrophotometric Determination Of Free Residual Chloride In Waters With 3,3'-dimethylnaphtidine"
Microchem. J. 1995 Volume 51, Issue 3 Pages 379-386
Pobozy E., Pyrzynska K., Szostek B. and Trojanowicz M.

Abstract: Water samples (200 µL) were injected into a carrier stream (2.2 cm/min) of water which merged with a stream (2.2 cm/min) of aqueous 0.002% 3,3-dimethylnaphtidine and passed through a reaction coil (50 cm x 0.5 mm i.d.) before detection of the oxidation product at 535 nm. The detection limit for Cl was 30 µg/l and the calibration graph was linear for 0.1-1 mg/l of Cl; the RSD (n = 10) at 0.4 mg/l Cl was 1.2% and the day-to-day RSD were 3%. Sample throughput was 150/h. Chloride, sulfate, nitrate, Fe(III), sulfite, nitrite, chromate, Cu(II), Mn(II) and Ca and Mg salts did not interfere. The results for tap and swimming pool water agreed well with those obtained by the standard NN-diethyl-p-phenylenediamine method.
Chloride, free Spectrophotometry Method comparison Interferences