Yamamoto Atsushi, Terao Tomoko, Hisatomi Hirotaka, Kawasaki Hideya, Arakawa Ryuichi
Kansai University, Department of Applied Chemistry, Faculty of Chemistry, Materials and Bioengineering, Suita, Osaka 5648680, Japan.
J Environ Monit. 2012 Aug;14(8):2189-94. doi: 10.1039/c2em30296a. Epub 2012 Jul 5.
An atmospheric pressure photoionisation (APPI) source for liquid chromatography/mass spectrometry (LC/MS) was applied to determine neonicotinoid pesticides in the aquatic environment. Dopant-assisted APPI was very effective in the ionisation of neonicotinoids. Neonicotinoids generated protonated molecules in APPI with high sensitivity, while adduct ions, such as sodiated molecules, were predominantly generated in conventional electrospray ionisation. The ionisation of neonicotinoids was confirmed by ultra-high-resolution MS. An analytical method coupled with solid phase extraction was developed for acetamiprid, clothianidin, dinotefuran, imidacloprid, nitenpyram, and thiamethoxam. Method detection limits were 0.47 to 2.1 ng L(-1) for six neonicotinoids. Dinotefuran was the most frequent and highest among the neonicotinoids examined in the aquatic environment in Osaka, Japan. The maximum concentration of dinotefuran was 220 ng L(-1). Given the toxicity of neonicotinoids for aquatic creatures, the concentrations observed here were substantially low. The change in concentrations was temporally coincident with the period of the neonicotinoid application. Although rapid photodegradation and some degradation products have been elucidated, the degradation products in the aquatic environment were not identified in the present study.
将一种用于液相色谱/质谱联用仪（LC/MS）的大气压光电离（APPI）源应用于测定水生环境中的新烟碱类农药。掺杂剂辅助的APPI对新烟碱类化合物的电离非常有效。新烟碱类化合物在APPI中能以高灵敏度产生质子化分子，而在传统电喷雾电离中主要产生加合离子，如钠化分子。通过超高分辨率质谱证实了新烟碱类化合物的电离。建立了一种结合固相萃取的分析方法，用于测定啶虫脒、噻虫胺、呋虫胺、吡虫啉、烯啶虫胺和噻虫嗪。六种新烟碱类化合物的方法检出限为0.47至2.1 ng L⁻¹。在日本大阪的水生环境中检测的新烟碱类化合物中，呋虫胺出现频率最高且含量最高。呋虫胺的最大浓度为220 ng L⁻¹。鉴于新烟碱类化合物对水生生物的毒性，此处观察到的浓度相当低。浓度变化在时间上与新烟碱类化合物的施用期一致。尽管已经阐明了快速光降解和一些降解产物，但本研究未鉴定出水生环境中的降解产物。
