Determination of aniline in silica gel sorbent by one-step in situ microwave-assisted desorption coupled to headspace solid-phase microextraction and GC-FID.
Microwave-assisted desorption (MAD) coupled to in situ headspace solid-phase microextraction (HS-SPME) was first proposed as a possible alternative pretreatment of samples in absorbent collected from workplace monitoring. Aniline collected on silica gel was investigated. Under microwave irradiation, the aniline was desorbed from silica gel and directly absorbed onto the SPME fiber in the headspace. Having been sampled on the SPME fiber, and desorbed in the GC injection port, aniline was analyzed using a GC-FID system. Parameters that affect the proposed extraction efficiency, including the extraction media and its pH, the microwave irradiation power and the irradiation time as well as desorption parameters of the GC injector, were investigated. Experimental results revealed that the extraction of a 150-mg silica gel sample using a 0.8-ml aqueous solution (pH 12) and a PDMS/DVB fiber under medium-high-powered irradiation (345W) for 3min maximized the efficiency of extraction. Desorption of aniline from the SPME fiber was optimal at 230 degrees C held for 3min. The detection limit was 0.09ng. The proposed method provided a simple, fast, and organic solvent-free procedure to analyze aniline from a silica gel matrix.
Yan
Cheing-Tong
CT
Department of Occupational Safety and Health, Chung-Shan Medical University, Taichung 402, Taiwan ROC; Department of Chemistry, National Chung-Hsing University, Taichung 402, Taiwan ROC.
Shih
Ton-Sheng
TS
Jen
Jen-Fon
JF