Application of multi-sorbent tubes filled with modified multi-walled carbon nanotubes for determining volatile organic compounds in a wide range of polarity

Abstract

New adsorbent M101 was obtained by loading multi-walled carbon nanotubes (MWCNTs) on 101 white support, and 3-aminopropyl silica gel–MWCNTs (APSG-MW) were prepared by chemical modification. Based on the early research, 15 kinds of adsorbents were tested to adsorb sulfide and amine compounds. Then 4 combinations of multi-sorbent tubes were prepared including Tenax TA/M101/Carbopack B (TMB), Tenax TA/M101/Carboxen 564 (TM564), Carbopack B/M101/Silica gel (BMS) and Carbopack B/APSG-MW/Silica gel (BAMS). The adsorption and desorption recoveries for alkanes, aromatic hydrocarbons, halogenated hydrocarbons, alcohols, esters, ketones, sulfides and amines were determined. The results showed that the recoveries of multi-layer adsorbents BMS and BAMS were above 90% for most of the target compounds, and 80% for amines. Then the influence of humidity on the sampling, storage stability and sampling precision of BMS and BAMS was tested. The results indicated that BMS and BAMS were more suitable for sampling both polar and non-polar compounds in the air.