Determination of N-Nitrosodimethylamine in Air by Combined Gas Chromatography-Thermal Energy Analysis

Abstract

We have established an analytical method for N-nitrosodimethylamine in air by the Tenax GC adsorption method. Air was sampled in a glass collection tube (8mm in diameter and 16 cm in length) packed with Tenax GC (O.8g) at a flow rate of 0.51/mmn for 40-60min at room temperature. The collection tube was set in a desorption device. The N-nitrosodimethylamine adsorped on the Tenax GC was desorbed at higher temperature in an argon flow (200° C, 40 m//min) and trapped in another glass tube (4mm in diameter and 18cm in length, GC tube) packed with Tenax GC (O.3g) at an argon flow rate of 40m1/min for 5min. Then the GC tube with the amine was set in the carrier gas line of a gas chromatograph, and the GC tube was heated for 1 min from room temperature to 200° C. The N-nitrosodimethylamine was determined with a gas chromatography-thermal energy analyzer. The present method was applied to determine N-nitrosodimethylamine in indoor and urban air. The N-nitrosodimethyl- amine levels found varied from 9 to 560 ng/m3.