Fernández M, Picó Y, Girotti S, Mañes J
Laboratori de Bromatologia i Toxicologia, Facultat de Farmàcia, Universitat de València, Avenida Vicent Andrés Estellés s/n, 46100 Burjassot, València, Spain.
J Agric Food Chem. 2001 Aug;49(8):3540-7. doi: 10.1021/jf010238m.
Pesticides applied in extended agricultural fields may be controlled by means of bioindicators, such as honeybees, in which are the pesticides bioaccumulate. Liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS) experiments with positive (PI) and negative (NI) ion modes were optimized for the analysis of 22 organophosphorus pesticides in honeybee samples. The extraction required 3 g of sample, which was extracted with acetone. The extract was purified with coagulating solution and reextracted with Cl(2)CH(2). Pesticides studied could be detected by both ionization modes except for parathion, parathion-methyl, and bromophos, which did not give signals in PI mode, and triazophos, which was not detected in NI mode. Fragmentation voltage and vaporizer temperature were optimized to achieve the highest sensitivity. The spectra profile of each pesticide in PI mode showed the M + H ion as the main signal, whereas in NI mode only fragment ions were shown. The detection limit obtained in selected ion monitoring mode ranged from 1 to 15 microg kg(-1). The average recoveries from spiked honeybees at various concentration levels (0.5-5 mg kg(-1)) exceeded 65% with relative standard deviations of 4-15%. The method was applied to real samples, in which residues of coumaphos and dimethoate were detected.
在广阔农田中施用的农药可通过生物指示物（如蜜蜂）进行监测，农药会在蜜蜂体内生物累积。采用正离子模式（PI）和负离子模式（NI）的液相色谱 - 大气压化学电离 - 质谱联用（LC - APCI - MS）实验对蜜蜂样本中22种有机磷农药的分析进行了优化。提取时需要3克样本，用丙酮进行提取。提取物先用凝聚溶液净化，再用二氯甲烷重新提取。除对硫磷、甲基对硫磷和溴硫磷在PI模式下无信号，以及三唑磷在NI模式下未被检测到外，所研究的农药在两种电离模式下均可被检测到。对碎裂电压和汽化器温度进行了优化以实现最高灵敏度。每种农药在PI模式下的质谱图以M + H离子作为主要信号，而在NI模式下仅显示碎片离子。在选择离子监测模式下获得的检测限范围为1至15微克/千克。在不同浓度水平（0.5 - 5毫克/千克）的加标蜜蜂样本中的平均回收率超过65%，相对标准偏差为4 - 15%。该方法应用于实际样本，检测到了蝇毒磷和乐果的残留。
