Pocket Colorimeter II by Hach

The new Pocket ColorimeterTM II Filter Photometer is a true go-anywhere instrument. It's lightweight and battery operated, suitable for extended field work or quick, on-the-spot process monitoring. The instrument has two channels in which measurements can be made. Each channel will accept a user-defined calibration curve. Up to 10 standards can be used to determine the calibration. The curve is generated by a point-to-point straight line segment between each standard used. Linear and non-linear positive or negative slope calibrations can be performed. A calibration curve may also be manually entered from the keypad if a previously determined curve has been made on the Colorimeter. At least two data pairs (concentration and absorbance) are required.

Test discs and reagent for semi-quantitative determination of fluoride ions in surface and ground water by

The fluoride test is especially suited for rapid control of fluoride concentrations.
Its purpose is to define concentration ranges and to detect values which fall
short of or exceed given limits.

A Simple Field Method For The Estimation Of Fluoride In Ground Waters For Common Man’s Use by S. V. Rao, Ritu Singh and S. C. Chaurasia

Fluoride is considered as an essential element forhuman beings. In potable waters, a fluorideconcentration of 1 μg/ml is necessary to preventtooth decay. However, at higher concentrations (>2μg/ml), it has adverse effects such as causingfluorosis. Fluoride toxicity is prevailant in variousparts of Andhra Pradesh, Madhya Pradesh andGujarat. Due to natural as well as anthropogeniccauses, the levels of fluoride in ground waters canimpossible by government laboratories. In order tomonitor fluoride, there is a need for fast, simple andcost effective method, which can be easily adaptedby common man. Visual colorimetric methods wouldbe the most suited for such applications. The mostcommonly used visual method is based onbleaching of Zirconium-Alizarin complex. Thismethod requires one hour for colour developmentand moreover, in this method, change in colour withfluoride concentration is gradual and hence a seriesof standards need to be prepared for quantification.This requires a skilled and experienced person.

Ground and River Water Quality Monitoring using a SmartPhone-Based pH Sensor by Sibasish Dutta, Dhrubajyoti Sarma, and Pabitra Nath

We report here the working of a compact and handheld smartphone-based pH sensor for monitoring of ground and river water quality. Using simple laboratory optical components and the camera of the smartphone, we develop a compact spectropho-tometer which is operational in the wavelength range of 400-700 nm and having spectral resolution of 0.305 nm/pixel for our equipment. The sensor measures variations in optical absorption band of pH sensitive dye sample in different pH solutions. The transmission image spectra through a transmission grating gets captured by the smartphone, and subsequently converted into intensity vs. wavelengths. Using the designed sensor, we measure water quality of ground water and river water from different locations in Assam and the results are found to be reliable when compared with the standard spectrophotometer tool. The overall cost involved for development of the sensor is relatively low. We envision that the designed sensing technique could emerge as an inexpensive, compact and portable pH sensor that would be useful for in-field applications.

Link : http://scitation.aip.org/content/aip/journal/adva/5/5/10.1063/1.4921835

Akvo Caddisfly Fast and easy drinking water fluoride testing using a smartphone by Hans Merton, Samuel Rajkumar

Akvo Caddisfly is a simple, fast, portable and low cost drinking water testing kit that can be used anywhere to quickly analyse the level of fluoride in drinking water, using a smartphone. Currently under development, it also allows water quality data to be accurately mapped and shared online. Both its hardware and software are open source.

Detection and Spatial Mapping of Mercury Contamination in Water Samples Using a Smart-Phone by Qingshan Wei, Richie Nagi , Kayvon Sadeghi , Steve Feng , Eddie Yan , So Jung Ki , Romain Caire, Derek Tseng and Aydogan Ozcan

Detection of environmental contamination such as trace-level toxic heavy metal ions mostly relies on bulky and costly analytical instruments. However, a considerable global need exists for portable, rapid, specific, sensitive, and cost-effective detection techniques that can be used in resource-limited and field settings. Here we introduce a smart-phone-based hand-held platform that allows the quantification of mercury(II) ions in water samples with parts per billion (ppb) level of sensitivity. For this task, we created an integrated opto-mechanical attachment to the built-in camera module of a smart-phone to digitally quantify mercury concentration using a plasmonic gold nanoparticle (Au NP) and aptamer based colorimetric transmission assay that is implemented in disposable test tubes. With this smart-phone attachment that weighs <40 g, we quantified mercury(II) ion concentration in water samples by using a two-color ratiometric method employing light-emitting diodes (LEDs) at 523 and 625 nm, where a custom-developed smart application was utilized to process each acquired
transmission image on the same phone to achieve a limit of detection of ∼3.5 ppb. Using this smart-phone-based detection platform, we generated a mercury contamination map by measuring water samples at over 50 locations in California (USA), taken from city tap water sources, rivers, lakes, and
beaches. With its cost-effective design, field-portability, and wireless data connectivity, this sensitive and specific heavy metal detection platform running on cellphones could be rather useful for distributed sensing, tracking, and sharing of water contamination information as a function of both space and time.

Link :  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3949663/pdf/nn406571t.pdf

Field Method For Estimation Of Fluoride In Drinking Groundwater By Photometric Measurement Of Spot On Aluminium Quinalizarin Reagent Paper By Zaher Barghouthi , Sameer Amereih

A simple field method for determination of fluoride in drinking water using handmade fluoride reagent paper impregnated by aluminium quinalizarin complex was developed. Fluoride reacts with the impregnated reagent paper to release the free ligand with new colour, orange different from that of the complex. The change in the colour, which is proportional to the amount of fluoride, was measured by the Arsenator. The functionality of the Arsenator which is based on a photometric measurement of spot on the reagent paper is expanded to analyse fluoride. The method allows a reliable determination of fluoride in the range 0.0–2.0 mg L1 Further spectrophotometric determinations of fluoride showed that Beer’s law is obeyed in the range of 0.3–5.0 mg L1 at 553 nm. Sensitivity, detection limit, quantitation limit, and the percentage recovery of 1.5 mg L1 fluoride were found to be 0.117 lg mL1., 0.1 mg L1 , 0.3 mg L1 and 101.2 respectively.

Link 1: http://www.sciencedirect.com/science/article/pii/S1878535213003948 

Sub-ppm Quantification Of Hg(Ii) In Aqueous Media Using Both The Naked Eye And Digital Information From Pictures Of A Colorimetric Sensory Polymer Membrane Taken With The Digital Camera Of A Conventional Mobile Phone by Hamid El Kaoutit, Pedro Estevez, Felix C. Garcia, Felipe Serna and Jose M. Garcia

We present colorimetric sensory membranes for detecting Hg(II) inaqueous media. The colour response of the sensory materials can be tuned for detection with the naked eye, such as the maximum contaminant level of Hg(II) that is set by the United States Environmental Protection Agency (EPA) for drinking water. Furthermore, the concentration of Hg(II) can be monitored using digital pictures of the membranes taken with conventional cameras. Thus, nanomolar concentration of Hg(II) could be detected by the naked eye due to colour changes of membranes, and the concentration of Hg(II) could be quantified, within the millimolar to nanomolar range, by means of analysing the digital information of pictures taken of the membranes after dipping them in water containing this environmentally poisonous cation.

Link :http://www.rsc.org/suppdata/ay/c2/c2ay26307f/c2ay26307f.pdf

Arsenic Treatment Technology Demonstration by Dennis Clifford, Ph.D. P.E. and Maxue Wu

This project involved four activities centered on evaluation of activated alumina adsorbents for arsenic removal. Several commercial adsorption media were tested by batch equilibrium protocols, and the influence of pH, silica and hardness on their arsenic sorption capacities was determined. Full adsorption isotherms were developed. A representative synthetic challenge water was developed, and its stability ascertained. A rapid small-scale column test for assessing sorption capacity was developed, to speed the evaluation of sorption media. Finally, the sorption capacities of several commercial media for two source waters from systems that must initiate arsenic removal were determined, using the new rapid column test.

Standard Methods for the Examination of Water and Wastewater by Water Environment Federation

A fluoride concentration of approximately 1.0 mg/L in drinking water effectively reduces dental caries without harmful effects on health. Fluoride may occur naturally in water or it may be added in controlled amounts. Some fluorosis may occur when the fluoride level exceeds the recommended limits. In rare instances the naturally occurring fluoride concentration may approach 10 mg/ L; such waters should be defluoridated. Accurate determination of fluoride has increased in importance with the growth of the practice of fluoridation of water supplies as a public health measure. Maintenance of an optimal fluoride concentration is essential in maintaining effectiveness and safety of the fluoridation procedure.