Dispersive micro solid-phase extraction for the rapid analysis of synthetic polycyclic musks using thermal desorption gas chromatography–mass spectrometry

• Published in: Journal of Chromatography A 2013-09, Vol.1307, p.34-40
• Main Authors: Chung, Wu-Hsun, Tzing, Shin-Hwa, Ding, Wang-Hsien
• Format: Article
• Language: English
• Subjects: Adsorbents; Analysis methods; Analytical chemistry; Applied sciences; Chemistry; Chromatographic methods and physical methods associated with chromatography; Design analysis; Desorption; Dispersive micro solid-phase extraction; Exact sciences and technology; Extraction; Freshwater; Gas chromatographic methods; Gas chromatography; gas chromatography-mass spectrometry; Mass spectrometry; Musk; Natural water pollution; Other wastewaters; Pollution; rapid methods; river water; silica; solid phase extraction; Synthetic musks; Thermal desorption-GC–MS; Wastewaters; Water analysis; Water treatment and pollution
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2013.07.074

A simple and solvent-free method for the rapid analysis of five synthetic polycyclic musks in water samples is described. The method involves the use of dispersive micro solid-phase extraction (D-μ-SPE) coupled with direct thermal desorption (TD) gas chromatography–mass spectrometry (GC–MS) operating in the selected-ion-storage (SIS) mode. The parameters affecting the extraction efficiency of the target analytes from water sample and the thermal desorption conditions in the GC injection-port were optimized using a central composite design method. The optimal extraction conditions involved immersing 3.2mg of a typical octadecyl (C18) bonded silica adsorbent (i.e., ENVI-18) in a 10mL water sample. After extraction by vigorously shaking for 1.0min, the adsorbents were collected and dried on a filter. The adsorbents were transferred to a micro-vial, which was directly inserted into GC temperature-programmed injector, and the extracted target analytes were then thermally desorbed in the GC injection-port at 337°C for 3.8min. The limits of quantitation (LOQs) were determined to be 1.2–3.0ng/L. Precision, as indicated by relative standard deviations (RSDs), was less than 9% for both intra- and inter-day analysis. Accuracy, expressed as the mean extraction recovery, was between 74 and 90%. A preliminary analysis of the river water samples revealed that galaxolide (HHCB) and tonalide (AHTN) were the two most common synthetic polycyclic musks present. Using a standard addition method, their concentrations were determined to in the range from 11 to 140ng/L.