The GAB (Guggenheim, Anderson, and de Boer) equation [1, 2, 3] is a widely referenced model that is often used for the characterization of pharmaceuticals, excipients, and food [4, 5, 6, 7]. Three excipients: lactose, gelatin, and talc were characterized in a single sorption instrument using krypton adsorption and BET modeling to determine the as-received surface area, water sorption, and then krypton sorption to determine the impact of water sorption on the BET surface area. Continue reading
Micromeritics Instrument Corporation is proud to announce its national accreditation as a Post-Secondary Avocational/Professional Development Institution by the Accrediting Council for Continuing Education and Training (ACCET), an accrediting agency recognized by the United States Department of Education. Attendees of Micromeritics Learning Center courses can now earn nationally accredited Continuing Education Units (CEUs) for completion of instrument operator training. As a result of this prestigious recognition, Micromeritics Learning Center has relocated all its educational information and training to www.micro.edu . Continue reading
The selection of data used for fitting BET surface area is often an easy process using the MicroActive software. A broad range of isotherm data is selected and then the BET fit may be further refined to yield the specific surface area of a material. The process for data selection and optimization has been fully automated using the BET surface area rules advocated by Professor Jean Rouquerol, CNRS Marseille, FR. Prof. Rouquerol recommends the following criteria: Continue reading
Jack G. Saad, part of the Scientific Services group specialized in particle sizing, recently presented at the 2013 American Society of Brewing Chemists (ASBC) Conference in Tucson, AZ. The presentation, entitled “the particle size paradox,” was given before an audience of food scientists in the beverage industry.
Based on literature and conversations with attendees, particle sizing applications of interest include:
- Use of Electrical Sensing Zone (Elzone) for yeast counting, particulate counting, and cleaning validation.
- Use of Dynamic Image Analysis (Particle Insight) for shape and size analysis of diatomaceous earth used in filtering.
- Using Dynamic Light Scattering (NanoPlus AT) for nanobubble formation studies for controlling gushing of carbon dioxide in the presence of hydrophobins.
- Using Static Light Scattering (Saturn) for general particle sizing applications in food science, like flour.
Andrew D. D’Amico, part of the scientific services group specializing in characterization by physical and chemical adsorption, recently attended the spring 2013 meeting of the American Society for Testing and Materials (ASTM) catalyst committee (D32). For this meeting, Andrew prepared material for three topics of interest: static carbon monoxide (CO) chemisorption on supported platinum on alumina catalysts, dynamic carbon monoxide pulse chemisorption on supported platinum on alumina catalysts, and dynamic acid site characterization of zeolites by propylamines. Andrew also contributed to the discussion to keep and update the current standard of terminology relating to catalysts and catalysis (D3766).
MicroActive 2.0 and MicroActive for 3Flex include a powerful utility for including the pore size distribution from mercury porosimetry analyses with pore size distributions calculated from gas adsorption isotherms. This new import function allows users to rapidly view micro, meso, and macro pore size distributions in one easy to use application.