KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/kmitl/1

Browse

Search Results

Now showing 1 - 2 of 2
  • Some of the metrics are blocked by your 
    Item type:Publication,
    Reagent-free analytical flow methods for the soft drink industry: Efforts for environmentally friendly chemical analysis
    (2012-10-25)
    Mantim, Thitirat
    ;
    Saetear, Phoonthawee
    ;
    ;
    Chan-Eam, Sumonmarn
    ;
    Sereenonchai, Kamonthip
    The evolution of an entirely green analytical system for industrial quality control of carbonated drinks is described. The developed flow system is capable of providing analytical data of the dissolved CO <inf>2</inf>, sucrose, and color of a sample consecutively in real-time. The system has been carefully designed on the basis of "reagent-free", meaning that no added chemicals are required for the analysis. The system first vaporizes CO <inf>2</inf> from the soft drink in a gas-liquid separation chamber, with a channel for a flow of pure water as the CO <inf>2</inf> acceptor. The dissolved CO <inf>2</inf> alters the conductivity of the water stream, which is directly related to the concentration of CO <inf>2</inf> in the soft drink. The sucrose content is measured based on the "schlieren effect", the sample plug flows out of the vaporization chamber into a colorimeter with a near-infrared/light-emitting diode (NIR/LED) as light source. The schlieren effect arises at the boundary of pure water and soft drink with refraction of light in proportion to the sugar concentration. The system also measures the absorbance of the sample using an RGB-LED. The related principles and preliminary experiments as proof of concept are described as well as the construction of the flow system for this completely reagent-free analyzer. A simple flow injection system using the schlieren effect was also developed for rapid quantitative analysis of sugar in noncarbonated soft drinks. © 2012 IUPAC.
      1
  • Some of the metrics are blocked by your 
    Item type:Publication,
    A low-cost method for determination of calcium carbonate in cement by membraneless vaporization with capacitively coupled contactless conductivity detection
    (2010-05-15)
    Sereenonchai, Kamonthip
    ;
    ;
    Chan-Eam, Sumonmarn
    ;
    Saetear, Phoonthawee
    ;
    This work presents a flow analysis method for direct quantitation of calcium carbonate in cement without pretreatment of the sample. The method is based on online vaporization of CO<inf>2</inf> gas following acidification of the sample inside a small chamber that has a flow of acceptor solution passing around it. Solubilization of the CO<inf>2</inf> gas into the acceptor stream changes the conductivity of the acceptor solution causing an increase of signal at the capacitively coupled contactless conductivity detection (C<sup>4</sup>D) placed at the outlet of the vaporization chamber. This chamber is an adaption from previous work reported on 'membraneless vaporization' (MBL-VP). The method can be used in the quality control of production of mixed cement. These cement materials usually have calcium carbonate contents at high concentration range (e.g., 33-99% (w/w) CaCO<inf>3</inf>). Analysis of samples by this method is direct and convenient as it requires no sample pretreatment. The method is low-cost with satisfactory accuracy and acceptable precision. © 2010 Elsevier B.V.
      2