Determination of Tramadol in Aqueous Samples Using Solid Phase Microextraction Fiber Based on Sol-Gel Coating Reinforced with Multiwall Carbon Nanotube Followed by Gas Chromatography

In this work, a novel solid phase microextraction fiber based sol-gel coating technology reinforced with carboxylated multiwall carbon nanotube have been prepared, developed, and optimized to determine tramadol in environmental water samples using gas chromatography-flame ionization detector. To reinforce sol-gel and increase in the extraction efficiency of tramadol, the sol-gel coated fiber was reinforced with carboxylated multiwall carbon nanotube. This solid phase microextraction fiber is disposable. Therefore, there is no risk of cross-contamination or carryover. Parameters that affect the extraction efficiency such as pH, extraction time, sample volume, volume of organic solvent, desorption time, and type of nanomaterials were optimized. Under optimized condition, linearity was observed in concentration ranges of 0.01-10 µgL-1 with correlation coefficient 0.996. Limit of detection (S/N=3) and limit of quantification (S/N=10) were 0.005 and 0.01 µg L-1, respectively. Relative standard deviations (n=5) was 3.13%. Using carboxylated multiwall carbon nanotubes for reinforcement of sol-gel coating leads to increasing extraction efficiency and decreasing the limit of detection. The relative recovery in the real sample (environmental water sample) was 85%. The proposed method can be used as a simple and sensitive method for detection of analgesic drugs such as tramadol in environmental water samples to control the environmental pollution.