Pan Lixiang, Feng Xiaoxiao, Zhang Hongyan
College of Science, China Agricultural University, Beijing 100193, China.
Int J Environ Res Public Health. 2017 Jul 21;14(7):822. doi: 10.3390/ijerph14070822.
Pyrethrins are nowadays widely used for prevention and control of insects in leaf lettuce. However, there is a concern about the pesticide residue in leaf lettuce. A reliable analytical method for determination of pyrethrins (pyrethrin-and П, cinerin І and П, and jasmolin І and П) in leaf lettuce was developed by using gas chromatography-mass spectrometry (GC-MS). Recoveries of pyrethrins in leaf lettuce at three spiking levels were 99.4-104.0% with relative standard deviations of 0.9-3.1% ( = 5). Evaluation of dissipation and final residues of pyrethrins in leaf lettuce were determined at six different locations, including the open field, as well as under greenhouse conditions. The initial concentration of pyrethrins in greenhouse (0.57 mg/kg) was higher than in open field (0.25 mg/kg) and the half-life for pyrethrins disappearance in field lettuce (0.7 days) was less than that greenhouse lettuce (1.1 days). Factors such as rainfall, solar radiation, wind speed, and crop growth rate are likely to have caused these results. The final residue in leaf lettuce was far below the maximum residue limits (MRLs) (1 mg/kg established by the European Union (EU), Australia, Korea, Japan).
如今，除虫菊酯被广泛用于生菜中昆虫的防治。然而，人们对生菜中的农药残留存在担忧。通过气相色谱 - 质谱联用（GC-MS）建立了一种可靠的分析方法，用于测定生菜中的除虫菊酯（除虫菊酯 -Ⅰ和Ⅱ、瓜叶菊酯Ⅰ和Ⅱ、茉莉菊酯Ⅰ和Ⅱ）。生菜中除虫菊酯在三个加标水平下的回收率为99.4% - 104.0%，相对标准偏差为0.9% - 3.1%（n = 5）。在六个不同地点，包括露天田地以及温室条件下，对生菜中除虫菊酯的消解和最终残留进行了评估。温室中除虫菊酯的初始浓度（0.57 mg/kg）高于露天田地（0.25 mg/kg），田间生菜中除虫菊酯消失的半衰期（0.7天）短于温室生菜（1.1天）。降雨、太阳辐射、风速和作物生长速率等因素可能导致了这些结果。生菜中的最终残留量远低于最大残留限量（MRLs）（欧盟（EU）、澳大利亚、韩国、日本规定为1 mg/kg）。
