在尿液或血液样品1.0 mL中加入100 μg·L^-1芬太尼-d₅内标溶液100 μL和0.1 mol·L^-1盐酸溶液4 mL，振荡，离心。上清液过已活化的MCX固相萃取柱，将洗脱液氮吹至近干，残渣用体积比9：1的含0.1%（体积分数）甲酸的5 mmol·L^-1乙酸铵缓冲溶液-乙腈混合液溶解，并定容至1 mL，经0.22 μm有机滤膜过滤，采用超高效液相色谱串联质谱法（UHPLC-MS/MS）测定其中15种芬太尼类新精神活性物质的含量。以ACQUITY UPLC BEH C₁₈色谱柱为固定相，以不同体积比的含0.1%甲酸的5 mmol·L^-1乙酸铵缓冲溶液-乙腈混合液为流动相进行梯度洗脱。质谱分析中采用电喷雾离子源正离子（ESI⁺）模式和多反应监测（MRM）模式。结果表明，15种芬太尼类新精神活性物质标准曲线的线性范围均为0.5~50.0 μg·L^-1，检出限（3S/N）均为0.1 μg·L^-1。对空白样品进行加标回收试验和日内（n=6）、日间（n=6）精密度试验，回收率为81.1%~113%，测定值的相对标准偏差均小于15%。

100 μL of 100 μg·L^-1 fentanyl-d₅ internal standard solution and 4 mL of 0.1 mol·L^-1 hydrochloric acid solution were added into 1.0 mL of urine or blood sample. The mixture was oscillated and centrifuged, the supernatant was passed through activated MCX solid phase extraction column, and the eluent was blown to near dryness by nitrogen. The residue was dissolved in a mixture of 5 mmol·L^-1 ammonium acetate buffer solution including 0.1% (φ) formic acid and acetonitrile at volume ratio of 9:1, and its volume was made up to 1 mL. The solution was filtered through a 0.22 μm organic filter membrane, and 15 fentanyl-analogue new psychoactive substances were determined by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) with ACQUITY UPLC BEH C₁₈ column as the stationary phase and the mixtures of 5 mmol·L^-1 ammonium acetate buffer solution including 0.1%(φ) formic acid and acetonitrile at different volume ratios as the mobile phase for gradient elution. Electrospray ion source positive ion (ESI⁺) mode and multiple reaction monitoring (MRM) mode were adopted in MS analysis. As shown by the results, linear ranges of standard curves of 15 fentanyl-analogue new psychoactive substances were 0.5-50.0 μg·L^-1, with the same detection limits (3S/N) of 0.1 μg·L^-1. Tests for the spiked recovery and inter-day (n=6) and intra-day (n=6) precision were made on blank samples, giving results in the range of 81.1%-113%, with RSDs of the determined values less than 15%.