气相色谱-质谱法测定水体中5种典型有机紫外防晒剂

建立了水体中5种典型有机紫外防晒剂甲氧基肉桂酸乙基己酯（ethylhexyl methoxycinnamate，EHMC）、二苯酮-3（benzophenone-3，BP-3）、4-甲基苄亚基樟脑（4-methylbenzylidene camphor，4-MBC）、奥克立林（octocrylene，OC）和胡莫柳酯（homosalate，HMS）的气相色谱-质谱检测方法。对HMS、BP-3衍生化条件进行了系统的优化。以100 μL双（三甲基硅烷基）三氟乙酰胺（N，O-bis（trimethylsilyl） trifluoroacetamide，BSTFA）为衍生化试剂，在100 ℃下反应100 min。水样固相萃取选用Oasis HLB萃取柱（0.5 g），洗脱溶剂为乙酸乙酯-二氯甲烷（1：1，v/v），水样pH 3~5。该方法对5种化合物的检出限范围为0.5~1.2 ng/L，定量限范围为1.4~4.0 ng/L。最佳实验条件下，加标水样回收率为87.85%~102.34%，相对标准偏差（n=3）均小于5%。该方法成功地应用于昆明市第一污水厂进出口水样中目标物质的分析。

Determination of five representative ultraviolet filters in water by gas chromatography-mass spectrometry

A method for the determination of five representative organic UV filters: ethylhexyl methoxycinnamate (EHMC), benzophenone-3 (BP-3), 4-methylbenzylidene camphor (4-MBC), octocrylene (OC), homosalate (HMS) in water was investigated. The method was based on derivatization, solid phase extraction (SPE), followed by determination with gas chromatography-mass spectrometry (GC-MS). The variables involved in the derivatization of BP-3 and HMS were optimized, and SPE conditions were studied. For derivatization, 100 μL N,O-bis(trimethylsilyl) trifluoroacetamide (BSTFA) was used as derivatization reagent and reacted with BP-3 and HMS at 100 ℃ for 100 min. For SPE, the pH value of water sample was adjusted to 3-5. The Oasis HLB cartridges were employed and the solution of ethyl acetate and dichloromethane (1:1, v/v) was used as the eluting solvent, and good recoveries of the target compounds were obtained. The limits of detection (LODs) and the limits of quantification (LOQs) for the five target compounds in water samples were 0.5-1.2 ng/L and 1.4-4.0 ng/L, respectively. The recoveries of spiked water samples were 87.85%-102.34% with good repeatability and reproducibility (RSD<5%, n=3) for all the target compounds. Finally, the validated method was applied to analysis the representative UV filters in water samples collected from a wastewater treatment plant in Kunming city of Yunnan province.