Wastewater-based epidemiology (WBE) has become an objective and updated surveillance strategy for monitoring and estimating consumption trends of psychoactive substances (PSs) in the population. Firstly, magnetic shrimp shell biochar-based adsorbent (DZMBC) was synthesized and employed for extraction trace PSs from municipal wastewater. Proper pyrolysis temperature and increased KOH activator content favored the pore structure and surface area, thus facilitating extraction. DZMBC delivered exceptional extraction performance such as pH stability, anti-interference property, fast magnetic separation ability, reusability, and reproducibility. Then, a method based on magnetic solid-phase extraction (MSPE) followed by ultra-high-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) was developed, validated, and utilized for the quantitative determination of five PSs in real wastewater samples. Methodological validation results indicated a favorable linearity, low method limits of detection (1.00–4.75 ng/L), and good precisions (intra-day and inter-day relative standard deviations < 4.8%). Finally, an objective snapshot of Chongqing drug use and consumption pattern was obtained. Methamphetamine (MAMP) and 3,4-methylenedioxymethamphetamine (MDMA) were the prevalent illegal drugs in local. Both concentrations and per capita consumption of MDMA displayed a change (P < 0.05) between July and September, while no statistical differences were observed for each week.

基于废水的流行病学（WBE）已成为一种客观且更新的监测策略，用于监测和估计人口中精神活性物质（PS）的消费趋势。首先，合成了磁性虾壳生物炭吸附剂（DZMBC）并用于从城市废水中提取微量PS。适当的热解温度和增加的KOH活化剂含量有利于孔结构和表面积，从而有利于萃取。 DZMBC 具有卓越的萃取性能，如 pH 稳定性、抗干扰性、快速磁分离能力、可重复使用性和重现性。然后，开发、验证了一种基于磁固相萃取 (MSPE) 和超高效液相色谱-串联质谱 (UPLC-MS/MS) 的方法，并用于实际定量测定五种 PS。废水样品。方法学验证结果表明良好的线性、低方法检测限（1.00-4.75 ng/L）和良好的精密度（日内和日间相对标准偏差 < 4.8%）。最终获得了重庆市药品使用和消费模式的客观概况。甲基苯丙胺（MAMP）和3,4-亚甲二氧基甲基苯丙胺（MDMA）是当地流行的非法毒品。 7月至9月期间MDMA浓度和人均消费量均出现变化（P  < 0.05），但每周未观察到统计差异。