Determination of opiates in urine samples using a composite of covalent organic framework and polypyrrole as a sorbent for microextraction in a packed syringe combined with HPLC/UV

This study aimed to develop microextraction in a packed syringe (MEPS) method for the determination of the three opiates in urine samples. Covalent organic framework-polypyrrole- cetyltrimethylammonium bromide (COF-PPy-CTAB) nanocomposite, as an appropriate and highly efficient adsorbent, was synthesized and applied to the MEPS process. The analytes were separated and extracted on the solid phase surface of the adsorbent through π stacking, hydrophobic, and host-guest interaction and then eluted by a desorbing solvent. After synthesizing the composite and using it in the syringe as a substrate for analyte adsorption, the parameters affecting the extraction of the analytes were optimized and the calibration curve was obtained according to the optimum conditions. The results were linear in the concentration range of 0.5–1000 μg L ^− 1 with a coefficient of determination greater than 0.9945. The limits of detection and quantification were obtained in the range of (0.1–1.0) and (0.5–5.0) μg L^‒1, respectively. The precision of the work was obtained for a syringe in a day and between days and also syringe to syringe in the range of 4.4–6.1%, 6.5–8.1%, and 7.8–10.1%, respectively. The preconcentration factors of 17, 20, and 16 were obtained for codeine, papaverine, and naltrexone, respectively. Relative recoveries of the drugs from urine samples were in acceptable range of 94.4–100.6% for codeine, 99.3–103.1% for papaverine and 95.0–98.9% for naltrexone.