Supporting information
Graphene oxide-reinforced polymeric ionic liquid monolith
solid-phase microextraction sorbent for high performance liquid
chromatography analysis of phenolic compounds in environmental
aqueous samples
Min Sun, Yanan Bu, Juanjuan Feng*, Chuannan Luo
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong
(University of Jinan), School of Chemistry and Chemical Engineering, University of
Jinan, Jinan 250022, China
*Correspondence:
Dr. Juanjuan Feng, Key Laboratory of Chemical Sensing &
Analysis in Universities of Shandong (University of Jinan), School of Chemistry and
Chemical Engineering, University of Jinan, Jinan 250022, China; E-mail:
chm_fengjuanjuan@ujn.edu.cn (J. Feng); Fax: +86-536-89736065
2.1 Chemicals and regents
1-(3-Aminopropyl)imidazole, 4-(chloromethyl)styrene, sodium 4-styrenesulfonate,
2,5-dichlorophenol and 2,4,6-trichlorophenol were purchased from J&K Scientific
Ltd. The 4-(chloromethyl)styrene was purified by vacuum distillation before use.
2-Nitrophenol, 3-nitrophenol, 4-chlorophenol, 2-methylphenol, and ammonium
hexafluorophosphate (NH4+PF6-) were purchased from Shanghai Jingchun Industry
Co. (Shanghai, China). Azobisisobutyronitrile (AIBN) was obtained from Shanpu
Chemical Co. (Shanghai, China) and purified by recrystallization before use.
1,6-Dibromohexane and 1-vinylimidazole were purchased from Sinopharm Chemical
Reagent Co. Ltd. (Shanghai, China). Graphene oxide was prepared according to the
modified Hummers method [1] in our laboratory.
Stock standard solutions of 2-nitrophenol, 3-nitrophenol, 4-chlorophenol,
2-methylphenol, 2,5-dichlorophenol and 2,4,6-trichlorophenol analytes were prepared
in ethanol at 1.0 mg mL-1 and stored at 4 °C. Working aqueous solutions were
prepared by appropriate dilution of stock solution with distilled water.
2.2 Instrumentation
An Agilent 1260 series HPLC system (Agilent Technologies, USA) with a 20 µL
sample loop and a diode array detector (DAD) was used for all the analysis. The
separation was performed on an Agilent Zorbax SB-C18 column (250 × 4.6 mm I.D.,
5 μm, USA) at 25 °C with a flow rate of 1.0 mL min-1. The gradient elution was
performed with acetonitrile (solvent A) and aqueous solution of KH2PO4 (pH 3.5)
(solvent B). For the separation of target phenolic compounds, the acetonitrile
composition was firstly set at 50% for 8.0 min, and then increased linearly from 8.0
min to 15.0 min until 80%. The DAD wavelength was set at 210 nm.
Surface morphological studies were performed by a field-emission scanning
electron microscope (SEM, SUPRATM55, Carl Zeiss, AG, Germany).
References
[1] Hummers, W.S., Offeman, R.E., J. Am. Chem. Soc. 1958, 80, 1339-1939.
Table S1 Chemical structures and properties of target analytes.
Water solubility
Analyte
Structure
Log P
pKa
2.00
8.36
13550
2.39
9.41
24000
1.79
7.23
2500
1.95
10.28
25900
3.06
7.51
2000
3.69
6.23
800
(mg L-1, 25 °C)
OH
3-Nitrophenol
NO2
OH
4-Chlorophenol
Cl
OH
NO2
2-Nitrophenol
OH
CH3
2-Methylphenol
OH
Cl
2,5-Dichlorophenol
Cl
OH
Cl
Cl
2,4,6-Trichlorophenol
Cl