J. Junsomboon and J. Jakmunee “A New Extraction Procedure and Differential Pulse Cathodic Stripping Voltammetric Method for Determination of Chromium(VI) Content in  Portland Cement  Products” (Poster Presentation), Pure and Applied Chemistry International Conference 2015 (PACCON2015) 21 - 23 January 2015. Amari Watergate Hotel, Bangkok, Thailand.