Simple Derivation of the pH at Which the Rate of Nitrosation of a Secondary Amine Is Maximized

TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 8 Issue 2 (2003) pp 112-115

Simple Derivation of the pH at Which the Rate of Nitrosation of a Secondary Amine Is Maximized

Michael D. Gernon* and Christine Trumpfheller

Atofina Chemicals, King of Prussia R&D Center, King of Prussia, PA 19406, michael.gernon@atofina.com
Received October 14, 2002. Accepted January 3, 2003.

Published online: 3 February 2003

Abstract. The rate of nitrosation of a simple secondary amine in aqueous solution is greatest at the pH that maximizes the total solution content of nitrous acid and free-base (unprotonated) secondary amine. The value of this pH, designated as pH_max,can be easily derived through consideration of the equilibria involved. The derivation of pH_max as given demonstrates that it is possible to predict from first principles some significant aspects of nitrosation kinetics. The importance of understanding pH_max with respect to promoting or avoiding nitrosamine formation is discussed.

Key Words: In the Classroom; physical chemistry; kinetics; Nitrosamine; N-nitrosoamine; nitrosation; nitrosating agent; nitrosamine control

(*) Corresponding author. (E-mail: gernon@atofina.com)

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