Mixed hemimicelle dispersive solid-phase extraction of methamphetamine from urine by ionic liquid coated silica nanoparticles.

Regarding the increasing trend of methamphetamine consumption in society, identifying and measuring low levels of methamphetamine in biological matrices is of great importance for clinical and forensic laboratories. Coated ionic liquid silica nanoparticles (CILSNPs) are appropriate adsorbent candidates to extract methamphetamine with high selectivity and sensitivity from complex urine matrix using the mixed hemimicelle dispersive solid-phase extraction (MHMDSPE) method. After successful characterization of synthesized CILSNPs by various techniques such as FTIR, XRD, SEM, and Zeta potential, the one-factor-at-a-time (OFAT) method was performed to optimize effective extraction parameters. HPLC-UV method was used to detect and quantify methamphetamines. The optimized extraction parameters were as follows: 400 µL of methanol, 10 min of extraction, 5 min of desorption time, stirring rate of 2,000 rpm, urine pH of 10, 40 mg of adsorbent, and 10 mL of urine volume. The calibration curve was plotted in the 50-2000 ng/mL concentration range, and the method was validated. The method's limit of detection (LOD) was calculated as 9 ng/mL. Analysis of addicted subjects for the proposed method proves that the method could be used in clinical and analytical laboratories to detect methamphetamine efficiently.