Static secondary ionization mass spectrometry detection of cyclohexylamine on soil surfaces exposed to laboratory air

Cyclohexylamine (CHA) is a common indoor air contaminant, which rapidly adsorbs to aluminosilicate soil samples. Static secondary ion mass spectrometry was used to study soil samples exposed to both CHA and CHA-d₁₁, and the results showed (1) abundant [M + H]⁺ and fragment ions that originated from CHA, (2) an initial concentration of CHA equivalent to approximately 0.2 monolayer, and (3) a possible exchange reaction where excess CHA-d₁₁ displaces CHA originally adsorbed to the surface. CHA was not removed from the surface by prolonged exposure to vacuum conditions (5 × 10^-7 torr), which indicates that CHA strongly adsorbs to aluminosilicate surfaces and should be expected as an endogenous surface contaminant where the chemical is used as a corrosion inhibitor. (J Am Soc Mass Spectrom 1996, 7, 168-172).