Titanium-based Solid Phase Extraction For The Sample Preparation In Environment Samples

PAH is a kind of POPs. Trace amount of PAHs can cause damage to human’shealth. It is very practical to analyze PAHs in environment samples. Samplepreparation is the key procedure for the analysis of PAHs. SPE and UAE are commonsample preparation methods for environment samples. Novel adsorbents for SPE haveattracted many researchers’ interest. We established several novel adsorbents whichwere based on Ti as the substrate for SPE of PAHs in environment samples, andHPLC-FLD was employed as the instrument for analysis. Several innovative workswere developed described as below:1. Titanium wire-based solid phase extraction （SPE） was developed for the analysis ofsix polycyclic aromatic hydrocarbons in water samples with coupling with highperformance liquid chromatography. The adsorbent was a Ti wire on which TiO2nanotubes were first formed by anodization and then Au nanoparticles andn-octadecanethiol were modified. The surface composition and structure of theadsorbent were characterized in detail using field emission scanning electronmicroscope and fourier transform infrared spectroscopy. The proposed adsorbenthas the advantages of both large surface area and hydrophobic properties. Goodlinearities with correlation coefficients （R2） ranging from0.9964to0.9999and lowlimits of detection were obtained in spiked water samples. Furthermore, thismethod was successfully applied in the analysis of real river water samples withrecoveries in the range of75.33–115.83%and relative standard deviations rangingfrom4.85to10.77%.2. In this work, ultrasonic assisted extraction combined with solid phase extraction（SPE） was applied in the analysis of polycyclic aromatic hydrocarbons （PAHs） inenvironmental samples. UAE was used to extract analytes from soil samples, whileSPE could remove interferents co-extracted along with the target compounds tomake the proposed method reliable. A titania nanotubes/titanium plate wasmodified with n-octadecanethiol monolayer-protected Ag nanoparticles, anddeveloped as the adsorbent in SPE of PAHs. The experiment conditions includingthe deposition time of Ag NPs, extraction solvent properties, the amount ofextraction solvent, the amount of organic modifier, extraction time, and desorptionsolvent properties were optimized. Under the optimized conditions, a good linearity and low limits of detection of0.0015-0.4ng g-1were obtained. The analysis ofPAHs in real soil samples gave satisfactory recoveries ranging from72.17%to118.16%.3. In this work, we carried out a simple treatment of titanium plate which was etchedin a solution made of HF、HNO₃、H₂O （1:3:6） for5min. The surface characteristicof the treated titanium plate was observed by field emission scanning electronmicroscope which demonstrated that coarse surface was formed. The treatedtitanium plate which had large surface area was applied as a novel adsorbent in SPEfor the analysis of PAHs in water samples. The main parameters affecting theextraction efficiency, such as the volume of the organic modifier, extraction time,elution solvent, and desorption time were optimized.