Pressurized Liquid Extraction And On-line Coupled With The Capillary Gas Chromagraphy

A pressurized liquid micro-extraction (PLE) method was developed andevaluated for the extraction of alkanes in particulate matter (PM10). Variablesaffecting the PLE efficiency such as the pressure, temperature, extraction time andtotal solvent volume of the extraction were studied and optimized. Comparativestudy between the PLE and ultrasonic extraction (UE) showed that the PLE wassuperior than that of UE both in efficiency and time. The recovery of the methodwas in the range of 96%-148%; the detection limit was 2-12ng/m3 with relativestandard deviation between 0.8% and 10.5%.The PLE was coupled on-line with CGC through a large-volume-injection(LVI) technique. Factors affecting the LVI such as solvents, injection speed andinitial temperature of the column were studied. The carry-over effects, linearity,limits of detection (LOD) were also evaluated. Finally, real life sample of PM10was analyzed by the on-line coupled system. The quantitation results and therecovery, repeatability and concentrations of 16 PAHs in real sample was given.Compared with conventional PLE extraction procedure, the on-lineminiaturized PLE-LVI-GC system transfers all the extract from the sample to theGC without split in only one extraction cycle. The absolute amounts of analytesthat entered into the analytical column are much higher than that obtained withconventional PLE method, improving the sensitivity more than 10 or even 100fold.