Co-exposure to tobacco and marijuana has become common in areas where recreational marijuana use is legal. To assist in the determination of the combined health risks of this co-exposure, an analytical method capable of simultaneously measuring tobacco and marijuana metabolites is needed to reduce laboratory costs and the required sample volume. So far, no such analytical method exists. Thus, we developed and validated a method to simultaneously quantify urinary levels of trans-3′-hydroxycotinine (3OH-COT), cotinine (COT), and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (COOH-THC) to assess co-exposure to tobacco and marijuana. Urine (200 µL) was spiked with labelled internal standards and enzymatically hydrolyzed to liberate the conjugated analytes before extraction using solid-supported liquid-liquid extraction (SLE) with ethyl acetate serving as an eluent. The target analytes were separated on a C18 (4.6 × 100 mm, 5 μm) analytical column with a gradient mobile phase elution and analyzed using tandem mass spectrometry with multiple reaction monitoring of target ion transitions. Positive electrospray ionization (ESI) was used for 3OH-COT and COT, while negative ESI was used for COOH-THC. The total run time was 13 min. The extraction recoveries were 18.4–23.9 % (3OH-COT), 65.1–96.8 % (COT), and 80.6–95.4 % (COOH-THC). The method limits of quantification were 5.0 ng/mL (3OH-COT) and 2.5 ng/mL (COT and COOH-THC). The method showed good accuracy (82.5–98.5 %) and precision (1.22–6.21 % within-day precision and 1.42–6.26 % between-day precision). The target analytes were stable for at least 144 h inside the autosampler (10 °C). The analyses of reference materials and 146 urine samples demonstrated good method performance. The use of a 96-well plate for preparation makes the method useful for the analysis of large numbers of samples.

在娱乐性大麻合法化的地区，同时接触烟草和大麻已变得很常见。为了帮助确定这种共同暴露的综合健康风险，需要一种能够同时测量烟草和大麻代谢物的分析方法，以降低实验室成本和所需的样品量。到目前为止，还没有这样的分析方法。因此，我们开发并验证了一种同时量化尿反式水平的方法-3'-羟基可替宁 (3OH-COT)、可替宁 (COT) 和 11-正-9-羧基-Δ9-四氢大麻酚 (COOH-THC) 用于评估烟草和大麻的共同暴露。在尿液 (200 µL) 中加入标记的内标，并进行酶水解以释放结合的分析物，然后使用固载液液萃取 (SLE)（以乙酸乙酯作为洗脱液）进行萃取。目标分析物在 C18 (4.6 × 100 mm, 5 µm) 分析柱上采用梯度流动相洗脱进行分离，并使用串联质谱法和目标离子跃迁的多反应监测进行分析。正电喷雾电离 (ESI) 用于 3OH-COT 和 COT，而负 ESI 用于 COOH-THC。总运行时间为 13 分钟。萃取回收率为 18.4–23.9% (3OH-COT)、65.1–96.8% (COT) 和 80.6–95.4% (COOH-THC)。定量的方法限为 5.0 ng/mL (3OH-COT) 和 2.5 ng/mL（COT 和 COOH-THC）。该方法显示出良好的准确度（82.5-98.5%）和精密度（日内精密度为1.22-6.21%，日间精密度为1.42-6.26%）。目标分析物在自动进样器 (10 °C) 内至少稳定 144 小时。对标准物质和 146 个尿液样本的分析表明了良好的方法性能。使用 96 孔板进行制备使得该方法可用于分析大量样品。对标准物质和 146 个尿液样本的分析表明了良好的方法性能。使用 96 孔板进行制备使得该方法可用于分析大量样品。对标准物质和 146 个尿液样本的分析表明了良好的方法性能。使用 96 孔板进行制备使得该方法可用于分析大量样品。