Teerasong, Saowapak

Loading...
Thumbnail Image
Preferred name
Teerasong, Saowapak
Alternative Name
Teerasong, S.
Main Affiliation
Email
saowapak.te@kmitl.ac.th

Settings

Now showing 1 - 2 of 2
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Miniaturized chromate-free chloride assay in fish sauce based on linear height calibration of AgCl precipitate in inverted microtubes
    (2026-06-01)
    Chantiwas, Rattikan
    ;
    Wilairat, Prapin
    ;
    Putthasa, Papawarin
    ;
    Cheotchinda, Benjamapohn
    ;
    Teerasong, Saowapak
    A miniaturized, chromate-free methodology for chloride determination in high-salt food matrices is presented in accordance with the principles of Green Analytical Chemistry. Classical argentometric precipitation is adapted to a microvolume, instrument-light assay by confining silver chloride formation within inverted microcentrifuge tubes and directly measuring the height of the compact precipitate layer using a simple ruler. Because the cylindrical tube region has a constant cross-sectional area, precipitate height is directly proportional to chloride concentration, enabling straightforward linear calibration without optical detection, signal transduction, or complex data processing. Controlled tube inversion and low-speed centrifugation ensure that precipitation occurs exclusively within this cylindrical zone, producing a sharp, reproducible solid–liquid interface. Under optimized conditions (150 µL sample volume and 180 µL of AgNO₃ in nitric acid; centrifugation at 600 rpm for 3 min followed by 5 min settling), the method provides a linear working range of 50–500 mM chloride (r² = 0.9988), a detection limit of 14 mM, and relative standard deviations of 3–4 % at 200–300 mM. Validation of 12 commercial Thai fish sauce samples showed no statistically significant differences compared to AOAC potentiometric titration at the 95% confidence level, with recoveries of 100–103 % and %RSD values of 1–4.2 %. The primary advantage of this method is its strictly linear height–concentration relationship, enabled by geometry-controlled confinement of the precipitate. Unlike other miniaturized or paper-based assays, it eliminates the need for image analysis or device fabrication. From a green chemistry perspective, the assay eliminates the use of potassium chromate indicators and disposable paper-based devices, operates at the microliter scale using reusable plastic microtubes, and requires only low-speed centrifugation. Analytical Greenness (AGREE), Analytical Eco-scale, Green Analytical Procedure Index (GAPI), and White Analytical Chemistry (WAC) evaluations (AGREE score: 0.76; Eco-scale: 83; WAC score: 88.9) classify the method as an excellent example of green analysis. The proposed approach offers a robust and sustainable screening tool for chloride determination in high-salt foods.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    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
    ;
    Teerasong, Saowapak
    ;
    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.