colorimetric detection Articles

  • AuNP‐based colorimetric aptasensor for rapid detection of six organophosphorus pesticides

    Fast immunoassay‐based screening methods are unavailable for most of small‐molecule pesticides due to lack of immunogenicity and the difficulty in obtaining antibodies by animal immunization. Aptamers are single‐stranded DNAs selected through an in vitro process, which can bind to any target including non‐immunogenic small molecules with high affinity and specificity. Though various ...


    By John Wiley & Sons, Ltd.

  • A colorimetric microwell method for determining bromide concentrations

    Bromide is commonly used as a tracer in studies of water and chemical transport in soil and rock because it is relatively nonreactive with soil and rock constituents and because of its low environmental background concentrations. Based on a largely ignored modification of an American Public Health Association standard colorimetric method for determining Br– using phenol red and chloramine-T(CT), ...

  • Highly sensitive colorimetric determination of malathion using gold nanoparticles

    A highly sensitive method is presented for the colorimetric determination of malathion using gold nanoparticles (AuNPs). In this approach, the synthesized AuNPs solution was stabilized by the citrate anions as their repulsion protected the AuNPs from aggregation. The synthesized AuNPs were characterized morphologically by using transmission electron microscopy technique. Malathion caps the ...


    By IWA Publishing

  • Plasmonic colorimetry: visual detection of environmentally relevant species

    Colorimetric detection of chemical species based on specially tailored noble metal nanoparticles is garnering increasing interest in the scientific community. The aggregation/dispersion of unmodified or ligand–functionalised plasmonic nanostructures upon binding to an environmental pollutant results in a colorimetric response, which can be easily discerned with the naked eye. This review ...


    By Inderscience Publishers

  • Phosphate detection in water - a potential amperometric approach

    Excess phosphorus causes eutrophication (excess of nutrient promoting a proliferation of plants, (especially algae) inecosystems. Consequently, the monitoring of phosphate in waste, drinking and natural water is of major importance.There is a strong interest in a method alternative to the standard molybdate colorimetric method, which is not well suited to continuous monitoring under field ...


  • Novel carotenoid-based biosensor for simple visual detection of arsenite: characterization and preliminary evaluation for environmental application

    A novel whole-cell arsenite biosensor was developed using the photosynthetic bacterium Rhodopseudomonas palustris no. 7 and characterized. A sensor plasmid containing the operator-promoter region of the ars operon and arsR gene from Escherichia coli and the crtI gene from R. palustris no. 7 was introduced into a blue-green mutant with crtI deleted, R. palustris no. 711. The biosensor changed ...

  • Honeywell gas detectors serve emergency backup role in U.S. rocket launch to destroy spy satellite

    A U.S. Standard Missile 3 (SM-3) enabled by Honeywell technology recently shot down a rogue U.S. spy satellite in space carrying over 1000 pounds of hydrazine, a highly toxic chemical used in rocket fuel. Meanwhile, Honeywell Analytics gas detection technology played a critical backup role in the operation: the company’s Single Point Monitor (SPM) was deployed at over 25 FEMA locations throughout ...


    By Honeywell Analytics, Inc.

  • EPA Compliant Letter

    APPENDIX I (Continued) B. Air Monitoring Equipment There are different methods available for air monitoring. These include colorimetric detector tubes (e.g., National Draeger, Sensidyne, Matheson-Kitagawa, MSA) and realtime remote sensing monitors (e.g., PureAire Monitoring Systems). NOTE: These air monitoring methods apply to enclosed areas, including greenhouse soil ...

  • A molecular imprinted polymer based sensor for measuring phosphate in wastewater samples

    Phosphate detection in water samples is still completed using colorimetric standard methods, which have a number of disadvantages, to such as being time consuming, requiring filtration, a number of different reagents, frequent calibration and proper disposal of waste chemicals generated. Hence, a simple cost effective analytical method and instrumentation is highly desirable to aid the ...


    By IWA Publishing

  • Heavy Metals Water Testing Powered by DNA

    Water pollution is a worldwide problem affecting developing and developed countries alike. Heavy metal contaminants are one prevalent type of water pollutant. They are persistent in the environment once d is charged and removal from source waters is necessary to ensure a clean drinking water supply. The problem of heavy metal pollution arises from several sources. Heavy metals such as uranium can ...


    By ANDalyze

  • PureAire’s Methyl Bromide Monitor Gains Exposure from the Department of Pesticide Regulation

    There has been an increased awareness for methyl bromide safety in the past few months. Over a year ago two employees at a cold storage warehouse got physically ill from high levels of methyl bromide. The Ch3br gas was off gassing from the products causing a higher than safe level for the employees. Commodities being shipped from overseas must be fumigated in ports, or warehouses upon arrival to ...

  • PureAire Methyl Bromide Monitor Gains Exposure from Lowered 5ppm criteria to 1 ppm Limit

    There has been an increased awareness for methyl bromide safety in the past few months. A year ago a worker got sick from breathing high levels of off gassing methyl bromide in a warehouse where commodities were being stored. Commodities coming from overseas must be fumigated in ports, or warehouses upon arrival. September 1, 2011 the California EPA will announce the regulations for methyl ...

  • Dissolved Organic Nitrogen Measurement in Reclaimed Water

    Dissolved organic nitrogen (DON) is an emerging concern for wastewater reclamation and reuse communities since DON may react with disinfectants to form carcinogenic nitrogenous disinfection byproducts (DBP) (e.g., haloacetonitriles, N-nitrosodimethylamine (NDMA)) and to affect the speciation of currently regulated DBP (trihalomethanes and haloacetic acids). Also, DON is present in proteins that ...

  • Aerating recycled water on mushroom composting sites affects its chemical analysis and the characteristics of odor emissions

    Recycled water (RW) containing compost leachate can be a potent source of foul odor on mushroom composting sites. Samples of RW were repeatedly collected from storage tanks and pits of 14 mushroom composting sites in England and Ireland. Relationships between the effects of submerged aeration of the RW, the chemical and microbial characteristics of the RW, and the odors emitted were investigated. ...

  • Induction of thymine dimers by solar radiation in natural freshwater phytoplankton assemblages in Patagonia, Argentina

    Natural phytoplankton assemblages from a freshwater lake in Trelew (Province of Chubut, Patagonia, Argentina) were exposed to natural solar radiation at different depths in a water basin filled with fresh water rich in humic substances. Samples were taken at regular intervals for DNA extraction and subsequent analysis of DNA damage by determining the formation of thymine dimers using an ...


    By Springer

  • Discrete or Continuous Flow Analysis – which is better?

    A wide variety of factors affect the choice of analytical instrument. These include target workload (samples/hour), variety of chemistries, methods required, bench space, staff availability etc. In the following article Lalicia Potter, Technical Sales & Support Director at SEAL Analytical, examines one of the common decisions facing laboratory managers. As the manufacturer of an ...

  • Wastewater engineers go with the flow

    The efficiency of maintenance work has been improved by water treatment engineers employing Intellisonde monitors in their final effluent. Designed primarily to measure water quality, the Intellisondes also measure flow, and this reading is being used to detect the accumulation of debris that necessitates a maintenance visit. Wastewater treatment efficiency is often measured by the analysis of ...


    By Intellitect Water Ltd

  • A Guide to Gas Detector Tubes. Your Questions Answered

    Gas detector tubes are easy to use, are low cost, and the method is intrinsically safe, allowing it to be deployed in all industries. Because detector tubes don’t require calibration, users see the benefits of this technology over electronic gas detectors due to their ease of ...


    By a1-cbiss

  • ITS marketing manager quoted in WaterTech

    Professional, ethical testing will start you off on the right foot and will directly determine which services the customer may need. Many substances could be in a customer’s water, but, “It’s not necessary to test for every parameter; that’s what labs are for,” advises Rob Samborn, director of sales and marketing for HM Digital, a Los Angeles-based maker of water ...

  • Is your Plant as tight as you think? Leak Detector for extremely toxic Gases, a Field Test Report

    Leak detection of commodity gases in chemical plants is a day-to-day practice. The sensor technology available for this application is field proven and reliable. No question about it, existing sensors will do the job. However, in plants manufacturing or handling extremely toxic substances, the picture is different. For example, take phosgene. The existing sensor technology for leak detection ...

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