scholarly journals Rapid laboratory method for the detection of chlorine in water

2004 ◽  
Vol 58 (3) ◽  
pp. 114-117 ◽  
Author(s):  
Jasmina Savic ◽  
Slobodanka Simic ◽  
Nikola Vukelic

The possibility of chlorine detection in water by using of amperometric sensor with dialysis membrane was investigated. The sensor consists of platinum cathode and silver anode, which were immersed in electrolyte whose pH was controlled. The calibration diagrams were constructed for different electrolytes and polarization potentials. The detection limit of 0.1 mg/dm3 was obtained, middle value of sensor sensitivity was approximatelly 14 nA/mgdm'3 and response time was less than 1 s for designed amperometric sensor in laboratory conditions.

2010 ◽  
Vol 7 (3) ◽  
pp. 284-287
Author(s):  
Ani Mulyasuryani ◽  
Qonitah Fardiyah ◽  
Rizki Sugiri

The iodate-selective electrode based on the principle of precipitation reaction could be made by coating the platinum wire with silver iodate (AgIO3). In this research was carried out optimization the iodate-selective electrode using chitosan membrane as an AgIO3 support. The AgIO3 were added in the 2 mL 1% chitosan solution, is 0.5 to 2.5 % (w/v). The thickness of the membrane used is 6 to 12 µm. The electrode cell potential is measured against Ag/AgCl electrode as a reference electrode. The optimum electrode performance was at 2.0 % of AgIO3 with thickness a membrane of 10 µm. The iodate-selective electrode has a Nernstian factor is 52.96 mV/decade and a response time of 10 seconds. The concentration range was determined from 10-3 M to 10-1 M and the detection limit is 1.12 x 10-5 M.   Keywords:  Ion Selective Electrode, Iodate, Chitosan Membrane


2020 ◽  
Vol 44 (41) ◽  
pp. 17849-17853
Author(s):  
Yanxia Qiao ◽  
Rui Zhang ◽  
Fangyuan He ◽  
Wenli Hu ◽  
Xiaowei Cao ◽  
...  

A glucose sensor based on conductive Ni-MOF nanosheet arrays/CC exhibits a fast response time, a low detection limit, a high sensitivity, and it can also be applied for the detection of glucose in human serum samples.


RSC Advances ◽  
2016 ◽  
Vol 6 (81) ◽  
pp. 77854-77862 ◽  
Author(s):  
Zeinab F. Akl ◽  
Tamer Awad Ali

Potentiometric screen-printed electrodes were constructed for Th(iv) determination in water samples. The optimized electrodes exhibited fast response time, wide linear range, low detection limit and high selectivity towards Th(iv) ions.


RSC Advances ◽  
2016 ◽  
Vol 6 (43) ◽  
pp. 37085-37092 ◽  
Author(s):  
Ying Yang ◽  
Li Sun ◽  
Xiangting Dong ◽  
Hui Yu ◽  
Tingting Wang ◽  
...  

Fe3O4nanoparticles-decorated reduced graphene oxide nanocomposites have been successfully synthesized using solvothermal-pyrolytic method. They have superior gas sensing performance with low detection limit, high sensitivity and short response time.


RSC Advances ◽  
2017 ◽  
Vol 7 (53) ◽  
pp. 33419-33425 ◽  
Author(s):  
Li Sun ◽  
Wencheng Fang ◽  
Ying Yang ◽  
Hui Yu ◽  
Tingting Wang ◽  
...  

Porous single-crystal In2O3 nanosheet was well-designed and prepared through calcination after liquid reflux, then exhibited a distinguished response, fast response time to NOx with good selectivity and low detection limit at room temperature.


2013 ◽  
Vol 76 (8) ◽  
pp. 1342-1349 ◽  
Author(s):  
PARDEEPINDER KAUR BRAR ◽  
MICHELLE D. DANYLUK

Tomato good agricultural practices, mandatory guidelines in Florida, do not have specific regulations for glove use during tomato harvesting. The objective of the research reported here was to evaluate Salmonella transfer from contaminated gloves to tomatoes and vice versa upon single and subsequent touches. Experiments were performed using mature, green, round tomatoes with two types of gloves (reusable and single use) and two hygienic conditions of reusable glove (clean and dirty [fouled with tomato leaves]). The transfer scenarios used during experiments were glove to tomato, tomato to glove, and glove to up to 25 subsequently touched tomatoes. The inoculated surface (6 log CFU per surface), after drying for 24 h, touched the uninoculated surface for 5 s. Salmonella populations from gloves and tomatoes were enumerated on nonselective and selective agar supplemented with 80 μg/ml rifampin. Enrichments were performed when counts fell below the detection limit. The rates of Salmonella transfer to tomatoes during a single touch were similar for single-use and reusable gloves; transfer from tomatoes to gloves was higher to single-use gloves than to reusable gloves under wet (0 h) inoculation conditions. Dirty reusable gloves did not transfer more Salmonella than clean reusable gloves during single contact under any conditions. When a single glove was sequentially touched to multiple tomatoes, clean reusable gloves transferred higher levels of Salmonella to the first few tomatoes touched than did single-use gloves and dirty reusable gloves. As workers' gloves became dirty over time during harvest, the risk of Salmonella transfer to tomatoes did not increase.


1969 ◽  
Vol 39 (1) ◽  
pp. 41-45
Author(s):  
Fernando Abruña ◽  
José Vicente

In determining the lime requirement of kaolinitic soils by direct titration with a calcium hydroxide solution it was found that boiling for 5 minutes reduced the time required for the attainment of equilibrium between the soil and the solution from over 100 hours to 1 hour. The variation in the pH values of the sons at equilibrium with the two methods were in all cases less than 0.1 unit. A precise, rapid laboratory method based on 5-minute boiling is described for determining the lime requirement of these soils. Results of a field experiment are shown to demonstrate the accuracy of the method.


2008 ◽  
Vol 6 (4) ◽  
pp. 607-612 ◽  
Author(s):  
Cecylia Wardak

AbstractA new all plastic sensor for Co2+ ions based on 2-amino-5 (hydroxynaphtyloazo-1′)-1,3,4 thiadiazole (ATIDAN) as ionophore was prepared. The electrode exhibits a low detection limit of 1.5 × 10−6 mol L−1 and almost theoretical Nernstian slope in the activity range 4.0 × 10−6–1 × 10−1 mol L−1 of cobalt ions. The response time of the sensor is less than 10 s and it can be used over a period of 6 months without any measurable divergence in potential. The proposed sensor shows a fairly good selectivity for Co(II) over other metal ions. The electrode was successfully applied for determination of Co2+ in real samples and as an indicator electrode in potentiometric titration of Co2+ ions with EDTA.


2014 ◽  
Vol 12 (3) ◽  
pp. 354-364 ◽  
Author(s):  
Cecylia Wardak

AbstractA new solid contact Zn2+ polyvinylchloride membrane sensor with 2-(2-Hydroxy-1-naphthylazo)-1,3,4 -thiadiazole as an ionophore has been prepared. For the electrode construction, ionic liquids, alkylmethylimidazolium chlorides are used as transducer media and as a lipophilic ionic membrane component. The addition of ionic liquid to the membrane phase was found to reduce membrane resistance and determine the potential of an internal reference Ag/AgCl electrode. The electrode with the membrane composition: ionophore: PVC: o-NPOE: ionic liquid in the percentage ratio of (wt.) 1:30:66:3, respectively, exhibited the best performance, having a slope of 29.8 mV decade−1 in the concentration range 3×10−7–1×10−1 M. The detection limit is 6.9×10−8 M. It has a fast response time of 5–7 s and exhibits stable and reproducible potential. It has a fast response time of 5–7 s and exhibits stable and reproducible potential, which does not depend on pH in the range 3.8–8.0. The proposed sensor shows a good and satisfactory selectivity towards Zn2+ ion in comparison with other cations including alkali, alkaline earth, transition and heavy metal ions. It was successfully applied for direct determination of zinc ions in tap water and as an indicator electrode in potentiometric titration of Zn2+ ions with EDTA.


Sign in / Sign up

Export Citation Format

Share Document