Sixto Alexandra, Niell Silvina, Heinzen Horacio
Facultad de Química, Departamento Estrella Campos, Química Analítica and Facultad de Química, Departamento de Química Orgánica, Grupo de Análisis de Compuestos Traza, Cátedra de Farmacognosia y Productos Naturales, Universidad de la República, 11800 Montevideo, Uruguay.
CENUR Litoral Norte, PDU Abordaje holístico al impacto de agroquímicos sobre alimentos y ambiente, Grupo de Análisis de Compuestos Traza, Universidad de la República, 60000 Paysandú, Uruguay.
ACS Omega. 2019 Dec 18;4(27):22632-22637. doi: 10.1021/acsomega.9b03538. eCollection 2019 Dec 31.
Contamination of honey with toxic pyrrolizidine alkaloids (PAs) and their N-oxides (PANOs) was assessed by dilution with acidic methanol and analysis through liquid chromatography (LC) coupled with tandem mass spectrometry (MS/MS) in three different modes. The hybrid linear trap/triple quadrupole (LC-QTRAP) instrument was used in precursor ion scan (PIS), enhanced product ion scan (EPI), and multiple reaction monitoring (MRM) mode. The parent ions from ions at / 120 or 138 amus, characteristic of all the toxic PAs and PANOs in the sample were first scanned by PIS. Then, the presence of each contaminant at specific retention times through its MS spectrum was confirmed by EPI. Finally, they were quantified in the MRM mode. The method was validated: recoveries 86-111%, relative standard deviation (RSD) <20%, at 20 and 40 μg/kg, except retrorsine, which showed a RSD of 30% at 20 μg/kg. Honey samples were analyzed and five of them showed levels of 40 μg/kg for the sum (PAs + PANOs). This approach allows the simultaneous determination of PAs and PANOs in honey, even if their chemical standards are not available.
通过用酸性甲醇稀释并采用液相色谱（LC）与串联质谱（MS/MS）联用的三种不同模式，评估蜂蜜中有毒吡咯里西啶生物碱（PAs）及其N-氧化物（PANOs）的污染情况。使用混合线性离子阱/三重四极杆（LC-QTRAP）仪器，分别以前体离子扫描（PIS）、增强产物离子扫描（EPI）和多反应监测（MRM）模式进行分析。首先通过PIS扫描样品中所有有毒PAs和PANOs特征的m/z 120或138处离子的母离子。然后，通过EPI根据其质谱图确认每种污染物在特定保留时间的存在。最后，在MRM模式下对它们进行定量。该方法经过验证：在20和40 μg/kg时回收率为86-111%，相对标准偏差（RSD）<20%，但倒千里光碱在20 μg/kg时RSD为30%。对蜂蜜样品进行了分析，其中五个样品中PAs和PANOs总量显示为40 μg/kg。即使没有它们的化学标准品，这种方法也能同时测定蜂蜜中的PAs和PANOs。
