Preparation Of New Adsorptive Materials And Its Application In Preservative Detection

Parabens（PBs）have excellent antibacterial properties and are widely used as preservatives in personal care products,cosmetics,food,health care products,and medicians.However,PBs are endocrine disruptors that interfere with the function of endogenous hormones by binding to estrogen receptors.The daily exposure of human body to PBs is estimated to be about 76 mg through three main sources including food,personal care products,and medicians.Excessive use of PBs can seriously threaten human health and lead to male infertility.Metal organic frameworks（MOFs）have high porosity and large specific surface area,and have specific adsorption with PBs.Therefore,in this dissertation,two new absorbent materials based on MOFs were prepared,and two sample pretreatment methods suitable for detecting paraben preservatives were established.The studies are as follows:（1）A new method for extracting paraben preservatives from personal care products was proposed.A novel adsorbent MOFs/Me S was prepared by combining polyvinylidene fluoride with melamine sponge（Me S）.The morphology and composition of the material was characterized by scanning electron microscopy（SEM）,Fourier transform infrared spectroscopy（FT-IR）,and powder X-ray diffraction（PXRD）.MOFs/Me S was used as solid phase extraction material to extract the sample solution,and combined with high performance liquid chromatography（HPLC）,it was applied to the extraction and detection of four PBs in the real samples.The detection limits of this method were 0.26–0.41 ng m L^-1.The linear range was 8–200 ng m L^-1.The inter-day and intra-day recorveries were 91.2–98.1%and 104.0–109.7%,respectively,with relative standard deviations（RSD）<13.8%.（2）A new method for the extraction of paraben preservatives from samples such as rainwater,skin care lotion,and fruit juice was proposed.Microfibrillated cellulose（MFC）skeletons of cotton were embedded with nanofibrillated MOFs,so that a new type of environmentally friendly absorbent material MOFs/MFC with good performance was prepared.First,a large amount of MOFs attached to the cellulose skeleton were observed through SEM.The structure of the complex was very stable and was not damaged by external force under 1800 rpm vortex oscillation.The adsorbent was characterized by energy dispersive X-ray analysis（EDX）,PXRD,FT-IR,and gas adsorption（BET）.Then,the water contact angle test and recycling test showed respectively that the material had good hydrophilicity and reusability（n≥10）.Finally,combined with HPLC,the adsorbent was applied to extracting and detecting four kinds of PBs from rainwater,skin care lotion,and fruit juice.The limits of detection were 0.29–0.58 ng m L^-1.The linear range was 2–500 ng m L^-1.The inter-day and intra-day recorveries were 90.7–106.0%and 87.1–109.3%,respectively,with relative standard deviations（RSD）<10.8%.