Tag Archives: surface area

New capabilities for the 3Flex – simultaneous analysis of three samples each using a different adsorptive

The Micromeritics 3Flex design includes metal seals, hard seal valves, and both a Pirani and cold cathode vacuum gauges.  The hardware is complemented by the state of the art software which continuously monitors  the status of the instrument.  These hardware and software feautures allow 3Flex users to perform adsorption experiments that were previously unavailable in multi-port instruments.  3Flex users may characterize three samples simultaneously and each sample may use a different adsorptive.   Continue reading

Krypton surface area and water sorption for common pharmaceutical excipients

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

Automatic selection of data points and optimization of BET surface area

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:
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