Ionic Liquid-modified NiTi Composite Nanosheets Coating for Efficient Solid Phase Microextraction of Octadecylamine in Brine
Huiju Wang *
School of Chemistry and Chemical Engineering, Qinghai Nationalities University, Xining 810007, China.
*Author to whom correspondence should be addressed.
Abstract
Ionic liquid (IL), 1-dodecyl-3-methylimidazolium-3-hydroxy-2-naphthoate (C12mimHNC) was synthesized and coated on the surface of NiTi as solid phase microextractiom fiber coating for determination the octadecylamine in brine. Prior to modification with IL, the NiTi was hydrothermally treated for in-situ growth of titanium and nickel oxide composite nanosheets (TiO2/NiOCNSs). The TiO2/NiOCNSs fibers coating was oriented around the NiTi substrate and presented double-faced open access sites, which provided a desired support framework for the further modification with IL. The extraction performance of C12mimHNC-TiO2/NiOCNSs fiber coating was evaluated for detection of octadecylamine (ODA) coupled to HPLC with UV detection. As a result, the C12mimHNC-TiO2/NiOCNSs fiber coating illustrated excellent adsorption and extraction capability for ODA. The main factors affected extraction efficiency were optimized. Under the optimized conditions, good linearity was obtained in the range of 1-150 µg/L with correlation coefficients (r2) above 0.985. Limits of detection (LODs) for the developed method was 0.280 µg/L. The proposed method was first applied to extract the ODA in brine samples. Relative recoveries varied from 78.3% to 96.5% at spiking level of 15µg/L and 30 µg/L with the relative standard deviations (RSDs) less than 8.7%.
Keywords: Ionic liquid, solid phase microextraction, titanium and nickel oxide composite nanosheets, octadecylamine, high-performance liquid chromatography.