The Sensitive and Selective Adsorption of Aromatic. Compounds with Highly Crosslinked Polymer Nanoparticles

Transcription

1 Electronic Supplementary Material (ESI) for Nanoscale. This journal is The Royal Society of Chemistry 2015 Supplementary Information The Sensitive and Selective Adsorption of Aromatic Compounds with Highly Crosslinked Polymer Nanoparticles Shuqin Liu, Darui Chen, Juan Zheng, Lewei Zeng, Jijun Jiang, Ruifeng Jiang, Fang Zhu, Yong Shen, Dingcai Wu, Gangfeng Ouyang* MOE Key Laboratory of Aquatic Product Safety/KLGHEI of Environment and Energy Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou , P. R. China. * To whom correspondence should be addressed. Tel.& Fax: cesoygf@mail.sysu.edu.cn.

2 Fig. S1. Theoretical C/H atomic ratio of the precursor and the HCP Fig. S2. FT-IR spectra and TG curves of the as-synthesized, boil water treated and methanol treated HCP nanoparticles.

3 Fig. S3. Relative responses of the dyes versus different concentrations and adsorption kinetics of the HCP toward different dyes obtained by UV-vis analysis. (A: methyl blue; B: nigrosine; C: acid orange 74.)

4 Fig. S4. Structures of the dyes. Fig. S5. Adsorption images of the HCP nanoparticles for prussian blue.

5 Fig. S6. Uv-vis Spectra of prussian blue before and after adsorption by HCP nanoparticles. Fig. S7. (A) Fluorescent adsorption of rhodamine B solutions before and after adsorption by HCP nanoparticles; (B) fluorescent spectra of pure rhodamine B power and the mixture of the HCP and the adsorbed rhodamine B after adsorption.

6 Optimization of the SPME condition for analysis of PAHs Several factors would affect the extraction results of the HCP coating, including desorption temperature, salt concentration, extraction time and extraction temperature. All of these factors were investigated and optimized to achieve the best enrichment efficiency for the self-made coating, as shown in Fig. S8. Desorption temperature. Several factors will influence the time needed to desorb target analytes and transfer them into the detector. In the case of thermal desorption into the GC inlet, desorption temperature is the main factor that influencing the rate of transfer. A suitable desorption temperature can not only eliminate the carry over but at the same time increase the sensitivity of the fiber. In order to obtain a better desorption efficiency and a better sensitivity, the desorption temperature was tested from 240 to 280 C. The extraction results shown in Fig. S8A reflected that the best desorption temperature was 280 C. Higher desorption temperature were not investigated because higher temperature would shorten the lifespan of the self-made coating. Therefore, 280 C was set as the desorption temperature for the subsequent experiments. Salt concentration. Addition of salt increases the ionic strength of the working solution, which results in the increase of the partition coefficient of the analyte between the coating and the sample matrix. The salting-out effect facilitates the transfer of the analyte from the sample matrix to the headspace. Therefore, addition of salts is commonly used to improve the sensitivity especially for HS-SPME. In order to investigate the effects of the salt concentration on the extraction efficiencies, the PAHs solutions with NaCl concentration ranged from 0 to 36% (w/v) were tested. Fig. S8B showed that the best extraction efficiency was obtained at salt concentration of 30% (w/v). Hence, content of NaCl in working solution was fixed at 30% (w/v) in the subsequent extractions. Extraction time. SPME, as a measure of free concentration of analyte in sample matrix, is an equilibrium extraction technique. Since equilibrium extraction provides the highest sensitivity, it is always adopted when the equilibrium time is acceptable. Herein, the extraction time profile was investigated from 20 to 90 min. As shown in Fig. S8C, all of the analytes reached extraction equilibrium at 80 min. In order to obtain the highest sensitivity, 80 min was selected as the optimal extraction time for the following experiments. As for the extraction time profile of naphthalene, the extraction amount decreased as the extraction time increased, which indicated that competitive adsorption occurred during the extraction. Extraction temperature. Extraction temperature has a twofold effect on experimental results. On the one hand, increasing the temperature could accelerate the diffusion rate. On the other, high temperature would lower down the partition coefficients of analytes between the coating and the water sample. Extraction efficiencies of five PAHs were tested in the range of 30 to 70 C. Based on the result illustrated in Fig. S8D, the extraction

7 amount of fluoranthene and pyrene increased as the extraction temperature increased. In contrast, when the temperature increased, the extraction amount of naphthalene and acenaphthene decreased. As for phenanthrene, the extraction amount climbed up and then declined as the temperature increased. Generally, the sensitivity of the method was determined by the analyte that exhibited the lowest response value. In order to improve the sensitivity of the method, 40 C was chosen as the optimal extraction temperature. Fig. S8. Effects of SPME conditions on the extraction efficiencies of the HCP nanoparticles coated fiber: (A) desorption temperature; (B) NaCl concentration; (C) extraction time; (D) extraction temperature.

8 Table S1. Comparison of equilibrium time and removal ratio for the aromatic dyes of the HCP and other reported materials HCP (this work) Dyes Equilibrium time Removal ratio Methyl blue, nigrosine and acid orange 74 3 min 96%, 97% and 94% CS/Mt-OREC microspheres 1 Methyl blue and methyl orange 60 min Nearly 95% and 60% N-dopted mesoporous carbon 2 Methyl blue and acid fuchsine 15 min Not given Ni-MCM-41 3 Methyl blue 60 min 73.7 % NH 2 -MCM-41 4 Acid fuchsine and acid orangⅡ 240 min 90.38% and 94.37% NH 2 -MIL-101(Al) 5 Methyl and methyl orange 2 h Not given Fe 3 O 4 /K x MnO 2 core shell architecture 6 Methyl blue 60 min 94% 1. L. Zeng, M. Xie, Q. Zhang, Y. Kang, X. Guo and H. Xiao, Carbohydr. Polym., 2015, 123, Á. Sánchez-Sánchez, F. Suárez-García, A. Martínez-Alonso and J.M.D. Tason, J. Colloid Interface Sci., 2015, 450, Y. Shu, Y. Shao, X. Wei, X. Wang, Q. Sun, Q. Zhang and L. Li, Microporous Mesoporous Mater., 2015, 214, Y. Wu, M. Zhang, H. Zhao, S. Yang and A. Arkin, RSC Adv., 2014, 4, E. Haque, V. Lo, A. I. Minett, A. T. Harris and T. L. Church, J. Mater. Chem. A, 2014, 2, X. Li, S. Song, X. Wang, D. Liu and H. Zhang, CrystEngComm, 2012, 14, 2866.

9 Table S2. Element analysis of the precursor and the HCP nanoparticles. C, % H, % C/N (mass ratio) C/N (atomic ratio) poly(dvb-co-vbc) precursor HCP nanoparticles Table S3. Maximum diameters and molar volumes of the PAHs Analytes Naphthalene Acenaphthene Maximum diameter a, Å Phenanthren e Fluoranthene Pyrrene Molar volume b, cm 3 mol a Maximum diameter of the analyte molecule was calculated as the distance between the two farthest-apart atoms plus the van der Waals radii of the two atoms (van der Waals radii of hydrogen, 1.2 Å) by ChemBio 3D Ultra b Molar volume were calculated by Guassian 09 software after operating the structure optimization procedure. Table S4. Analytical performance for GC-MS determination of PAHs using HCP nanoparticles coated fiber Analytes Linear LOD, ng L- range, ng L -1 R 2 1 LOQ, ng L - 1 RSD, % Single Fiber to fiber, n=5 fiber, n=3 Naphthalene Acenaphthene Phenanthrene Fluoranthene Pyrene

10 Table S5. Comparison of linear ranges and LODs of the HCP coated fiber and the reported fibers. Analytes Naphthalene Acenaphthene Phenanthrene Fluoranthene Pyrene HCP coated fiber LR a, μg L (this work) LOD, ng L Bio-MOF-102 LR a, μg L coated fiber 7 LOD, ng L LR a, μg L PIL coated fiber 8 LOD, ng L Etched stainless LR a, μg L steel wire fiber 9 LOD, ng L Nonylphenol LR a, μg L coated fiber 10 LOD, ng L Au nanoparticles LR a, μg L coated fiber 11 LOD, ng L N-dopted CNT LR a, μg L coated fiber 12 LOD, ng L OMP coated LR a, μg L fiber 13 LOD, ng L a LR: linear range. 7. S. Liu, Y. Zhou, J. Zheng, J. Xu, R. Jiang, Y. Shen, J. Jiang, F. Zhu, C. Su and G. Ouyang, Analyst, 2015, 140, L. Pang and J. Liu, J. Chromatogr. A, 2012, 1230, H. Xu, Y. Li, D. Jiang and X. Yan, Anal Chem., 2009, 81, A. Es-haghi, V. Hosseininasab and H. Bagheri, Anal. Chim. Acta, 2014, 813, Y. Zhang, Y. Yang, Y. Li, M. Zhang, X. Wang and X. Du, Anal. Chim. Acta, 2015, 876, H. C. Menezes, S. M. R. de Barcelos, D. F. D. Macedo, A. D. Purceno, B. F. Machado, A. P. C. Teixeira, R. M. Lago, P. Serp and Z. L. Cardeal, Anal. Chim. Acta, 2015, 873, J. Zheng, Y. Liang, S. Liu, Y. Ding, Y. Shen, T. Luan, F. Zhu, R. Jiang, D. Wu and G. Ouyang, Nanoscale, 2015, 7,