Insect repellents (IRs) are a group of organic chemicals whose function is to prevent the ability of insects of landing in a surface. These compounds have been found in the environment and may pose a risk to non-target organisms. In this study, an on-line solid phase extraction – high performance liquid chromatography-tandem mass spectrometry multiresidue method was developed using an atmospheric photoionization source (SPE-HPLC-(APPI)-MS/MS). The use of the APPI as an alternative ionization technique to electrospray (ESI) and atmospheric pressure chemical ionization (APCI) allowed expanding the range of analytical techniques suitable for the analysis of IRs, so far relied in gas chromatography. High sensitivity and precision was reached with method limits of quantification between 0.2 and 4.6 ng l⁻¹ and interday and intraday precision equal or below 15%. The validated method was applied to the study of surface water samples from three European river basins with different flow regime (Adige River in Italy, Sava River in the Balkans, and Evrotas River in Greece). The results showed that two IRs (DEET and Bayrepel) were ubiquitous in the Sava and Evrotas basins, reaching concentrations as high as 105 μg l⁻¹ of Bayrepel in the Sava River, and 5 μg l⁻¹ of DEET in the Evrotas River. Densely populated areas and effluent waste waters are pointed out as the responsible for this pollution. In the alpine river Adige, only three samples showed low levels of IRs (6.01–37.8 ng l⁻¹). The concentrations measured were used to perform an environmental risk assessment based on the hazard quotients (HQs) estimation approach by using the chronic and acute eco-toxicity data available. The results revealed that despite the high frequency and eventually high concentrations of these IRs determined in the three basins, only few sites were at risk, with 1 < HQs < 3.3.

驱虫剂（IR）是一组有机化学物质，其功能是防止昆虫在表面上着陆。这些化合物已在环境中发现，可能会对非目标生物造成危险。在这项研究中，使用大气光电离源（SPE-HPLC-（APPI）-MS / MS）开发了在线固相萃取-高效液相色谱-串联质谱多残留方法。APPI作为电喷雾（ESI）和大气压化学电离（APCI）的替代电离技术的使用，扩大了适用于IR的分析技术的范围，到目前为止，气相色谱一直依赖于该技术。方法的定量极限在0.2到4.6 ng l ^-1之间，达到了高灵敏度和精密度日间和日内精度等于或低于15％。经验证的方法用于研究三个不同流域的欧洲流域（意大利的阿迪杰河，巴尔干的萨瓦河和希腊的埃夫罗塔斯河）的地表水样品。结果表明，2的IR（DEET和Bayrepel）分别在萨瓦和Evrotas盆地无处不在，达到浓度高达105微克升^-1在萨瓦河Bayrepel的，和5μg升^-1在Evrotas河DEET的。指出人口稠密的地区和废水是造成这种污染的原因。在高山阿迪杰河中，只有三个样品显示出低水平的IR（6.01–37.8 ng l ^-1）。通过使用可获得的慢性和急性生态毒性数据，将所测量的浓度用于基于危险系数（HQs）估算方法的环境风险评估。结果表明，尽管在三个流域中确定了这些IR的频率很高，而且最终浓度很高，但只有少数站点处于危险之中，其中1 <HQs <3.3。