| Benzophenones(BPs)are a widely used ultraviolet filter due to their superior ultraviolet(UV)absorption properties and compatibility with other materials.However,as an environmental endocrine disruptor,BPs will cause the decline of human reproductive system function and the disorder of animal male estrogen secretion function.It is reported that BP-type ultraviolet filters(UV filters)used in plastic food packaging will migrate to food and harm human health,and BPs residues in environmental water have potential bioaccumulation,which can cause endocrine disorders and developmental toxicity.Therefore,more and more attention has been paid to the rational and safe use of BP-type UV filters.It is very necessary to develop a reliable sensitive detection technique for BP-type UV filters.Capillary electrophoresis(CE)has the unique advantages of high efficiency,fast anlaysis and wide sample adaptability,while mass spectrometry(MS)provides high sensitivity and qualitative ability to provide molecular weight and structure information.CE-MS has become an important analytical method in the field of biology,medicine and food packaging.In this thesis,a high sensitivity analytical method based on sheathless capillary electrophoresis,electrospray and tandem mass spectrometry(CE-ESI-MS/MS)was developed for the detection of trace BP-type UV filters in food packaging materials and environmental water samples.In the first part of the thesis,a sheathless CE-ESI-MS/MS method is developed and applied for the first time to sensitively detect BP-type UV filters in plastic food packaging materials.Comparing to sheath-liquid CE-MS,using a sheathless interface to couple CE and ESI-MS/MS can significantly increase the detection sensitivity.We investigate and optimize a variety of factors that may affect ESI-MS efficiency and CE separation.The method exhibits excellent inter/intra-day repeatability along with the advantages of efficient separation,rapid analysis,low sample consumption and high sensitivity.The detection limit of six BP-type UV filters is 7 pg/mL-2.4 ng/mL.Six BP-type UV filters in eight different brands of plastic films are successfully analyzed using the method.Good recoveries of 81.3-104.1%at three levels of spiked concentrations are achieved with low RSDs(n=5)of 2.5-8.7%.Our study shows that the sheathless CE-ESI-MS/MS is a robust and reliable method for sensitive and rapid analysis of BP-type UV filters,which would be of potential application in safety assessment of plastic food packaging materials.The second part of the thesis,a novel polyaniline-modified core-shell mesoporous silica(CSMS@PANI)nanocomposite microsphere was synthesized as an adsorbent.Aiming at the requirements of high sensitivity and high selectivity for the analysis of trace BP-type ultraviolet filters in environmental water samples,a high-efficiency enrichment and purification dispersion solid-phase extraction method(d-SPE)was proposed,and applied in the efficient and sensitive detection of BP-type UV filters in environmental water samples by combining with sheathless CE-ESI-MS/MS.The synthesized CSMS@PANI nanocomposite microsphere has the advantages of uniform fibrous shell(microsphere diameter is 1.3?m,outer silica shell thickness is 120 nm,pore diameter is 12.04 nm)and large specific surface area(33.45m~2/g).We investigate and optimize a variety of factors that may affect the enrichment and purification of d-SPE.The detection limit of six BP-type UV filters is 0.6pg/mL-0.2 ng/mL,and the enrichment factors are 470-660 times.Studies have shown that the d-SPE-sheathless CE-MS/MS method based on CSMS@PANI nanocomposite microsphere has the advantages of rapid,efficient enrichment,high sensitivity and excellent inter/intra-day repeatability.It is a reliable method for analysis of trace BP-type UV filters and has potential application value in environmental water sample safety evaluation. |
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