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A new analytical approach, based on derivatization with 2,2,2-trichloroethyl chloroformate and gas chromatography/mass spectrometry (GC/MS), was investigated for qualitative and quantitative analyses of a large range of amphetamine-related drugs and ephedrines in plasma, urine and hair samples. Sample preparation involved alkaline extraction of analytes from biological samples using Extrelut columns, after addition of the internal standard 3,4-methylenedioxypropylamphetamine (MDPA), and subsequent derivatization to produce 2,2,2-trichloroethylcarbamates. GC/MS analyses, in splitless mode using a slightly polar 30-m capillary column, were performed with quadrupole or ion trap instruments. MS acquisition modes were electron ionization (EI) in full-scan or selected ion monitoring (SIM) modes (quadrupole), and full-scan MS or MS/MS modes with chemical ionization (CI) conditions (ion trap). EI spectra of 2,2,2-trichloroethylcarbamates showed variably abundant molecular ions as well as abundant diagnostic fragment ions, both characterized by ion clusters reflecting the isotope distribution of three chlorine atoms in the derivatized molecules. CI spectra showed abundant protonated molecules. Quantitative studies using EI SIM conditions gave recoveries in the range 74-89%, linear response over ranges of 10-2000 ng/mL (plasma and urine) and 0.20-20 ng/mg (hair), with corresponding limits of detection in the ranges 2-5 ng/mL and 0.1-0.2 ng/mg. Potential applications (following full method validation) include clinical and forensic toxicology, as well as doping control.

Hydrogels have drawn intensive attention as emerging materials for various applications in wearable sensors, soft robotics, and implantable devices. However, fabricating hydrogels with UV-shielding and antioxidant properties still remains a challenge. Herein, we prepared biocompatible 3-allyloxy-2-hydroxypropyl-lignin/polyacrylic acid (AHP-lignin/PAA) hydrogels with self-adhesion, conductivity, UV shielding, and antioxidant activity as wearable sensors by the incorporation of lignin into PAA. The structure, lap shear strength, and biocompatibility were characterized using the UV–vis spectrometer, universal testing machine, and cell test. The hydrogels showed strong adhesion to various substrates. The AHP-lignin/PAA hydrogels had excellent UV shielding and free radical scavenging capacity. Meanwhile, AHP-lignin/PAA hydrogels exhibited excellent sensitivity to tiny changes in low pressure. Notably, the hydrogels could adhere to the skin well without any other adhesives to monitor the movement signals of the body motion accurately. The biocompatible AHP-lignin/PAA hydrogels with self-adhesion, conductivity, UV shielding, and antioxidant activity offer great potential applications in wearable sensors.