Preparation Of Solid Glass Microspheres And The Study On Sorptive Extraction Of PAHs In Aqueous Sample

The Solid-phase microextraction (SPME), introduced in 1990, is a solvent-free sample pretreatment technique, which allows extraction, concentration and sample introduction to be done in a single step. It is simple, high efficiency, friendly to entironment and can coupled directly to gas chromatography(GC) and liquid chromatography(LC). So far the SPME has developed into many kinds of modes, such as Fiber-SPME, In-tube SPME, Stir Bar Sorptive extraction(SBSE). Especially SBSE, it possesses large amount of sorptive extraction phase and consequently extremely high sensitivities can be obtained. SBSE offers SPME a dominant trends.In-house coating preparations of SPME were commonly accomplished by Sol-gel method, which was completed in gentle conditions and the process could be easy controlled. In this study, a novel extraction medium, Solid Glass Microspheres(SGMs) was prepared by Sol-gel method. Single factor and orthogonal test method were applied for optimizing proportion of ingredients used in sol solution. The processing of dryness and aging was also optimized. In optimum conditions, SGMs were prepared, and the surface of the SGM was uniform checked by SEM. The coating exhibited satisfactory property undergoing organic solvent and ultra temperature. A homemade thermal desorption system which is suited for SGMs was assembled and coupled to Shimadzu GC-14C.Six PAHs in water sample were detected by SGMs coupled with TDS-CGC-FID. The effect of pre-column was discussed, and the identity in same batch and the identity between different batches were also studied. Many factors influencing extraction efficiency, such as stirring conditions, extraction time, ion strength, desorption temperature, desorption time and desorption times, were discussed. Under optimum conditions, Six PAHs in water sample were tested. The limit of detection is 6 pg/mL, and the liner range is from 0.08ng/mL to 96ng/mL. The RSD for peak area and retention time were under 6.65%, 0.019% respectively. Relative recovery of spiked PAHs in water sample were between 78% and 127%. SGMs as a attempt of novel extraction medium, has disadvantage in many aspects, and needed further studies.