凝固漂浮有机液滴-分散液液微萃取-高效液相色谱-串联质谱法测定海水中苯并三唑类紫外线过滤剂

建立了海水中7种苯并三唑类紫外线过滤剂的凝固漂浮有机液滴-分散液液微萃取-高效液相色谱-串联质谱分析方法。优化后的萃取实验条件：20 μL十二醇为萃取溶剂，400 μL甲醇为分散溶剂，NaCl质量分数为8%，pH小于6，涡旋振荡时间2 min。目标化合物经Hypersil GOLD色谱柱（150 mm×2.1 mm，5 μm）结合甲醇-水梯度洗脱分离后，用正离子多反应监测模式进行质谱分析。在较宽的线性范围内，7种化合物的线性相关系数（r²）均大于0.99；基质加标回收率为68.3%~127.5%，相对标准偏差为0.9%~15.2%，方法的检出限为0.001~0.090 μg/L，定量限为0.003~0.300 μg/L。将建立的方法用于大连8个海滨浴场海水中苯并三唑类紫外线过滤剂的测定，部分浴场海水有不同程度的检出。该方法简便、快速、环境友好、灵敏度高，可用于海水中苯并三唑类紫外线过滤剂的分析检测。

Dispersive liquid-liquid microextraction based on solidification of floating organic droplets combined with high performance liquid chromatography-tandem mass spectrometry for determination of benzotriazole ultraviolet stabilizers in seawater

A novel dispersive liquid-liquid microextraction method based on solidification of floating organic droplets (DLLME-SFO) technique was developed for the determination of seven benzotriazole ultraviolet (UV) stabilizers in seawater samples by high performance liquid chromatography with tandem mass spectrometry. The optimal liquid-liquid microextraction experiment conditions were as follows: 20 μL of 1-dodecanol as extraction solvent, 400 μL of methanol as dispersive solvent, 8% (mass percentage) NaCl, pH of the sample below 6, vortex oscillation extraction time in 2 min. The separation of target compounds was achieved by combining a Hypersil GOLD analytical column (150 mm×2.1 mm, 5 μm) with methanol-water as mobile phase with gradient elution program. Quantitative determination by ESI-MS/MS was achieved using positive ion mode with multiple reaction monitoring mode. The proposed method showed good linearity with the correlation coefficients all above 0.99. The blank samples were spiked at three levels and the average recoveries of target compounds ranged from 68.3% to 127.5% with the RSDs from 0.9% to 15.2%. The limits of detection (LODs) and limits of quantification (LOQs) of the method for the seven target compounds were in the ranges of 0.001-0.090 μg/L and 0.003-0.300 μg/L, respectively. The developed method was successfully applied for the analysis of the UV stabilizers in seawater at Dalian seashores, and some of the benzotriazoles were detected. The method is simple, rapid, environment friendly, highly sensitive and suitable for rapid analysis of benzotriazole UV stabilizers in seawater.