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菠菜中极性农药的快速、可靠的直接分析 

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  • 无需执行费时的衍生化或离子配对步骤,也无需长时间等待色谱柱平衡。
  • 独特的固定相提供了良好的保留和有效的洗脱,可形成更好的峰形。
  • 稳定的色谱柱性能可确保色谱分析的一致性和可靠的结果。

对极性农药(如草甘膦及其主要代谢物 AMPA 和草铵膦)进行直接分析是很困难的,因为它们不能很好地保留在反相柱上,并且与 LC-MS/MS 中的金属表面的螯合可显著降低响应。衍生化和离子配对试剂通常用于改善性能,但它们需要额外的样品制备时间,并且可能产生不良的副作用(沉淀、较长的平衡时间、系统污染等)。

使用 Raptor Polar X 柱是一个更好的解决方案,因为其新的固定相提供了与极性阴离子化合物更强的相互作用。它具有混合保留模式(HILIC 和离子交换),并提供强保留,但仍然允许分析物通过简单的流动相变化快速洗脱为对称峰。在这次对菠菜的极性农药的分析中,这三种化合物的色谱性能都很好,总分析时间只有 8 分钟。此外,通过数百次的基质注射,峰形和保留时间仍能保持稳定,并且简单地更换保护柱即可恢复全部性能。这种快速、简单、有效的工作流程是对极性农药的直接分析感兴趣的食品实验室的一个很好的选择,它不需要复杂和耗时的程序。

cgarm-img
LC_FS0547
PeaksConc.
(ng/mL)
Precursor IonProduct Ion 1Product Ion 2Product Ion 3
1.AMPA100110.1079.0563.1081.10
2.Glufosinate100180.2085.1595.10-
3.Glyphosate100168.1063.0579.05-
ColumnRaptor Polar X (cat.# 9311A32)
Dimensions:30 mm x 2.1 mm ID
Particle Size:2.7 µm
Pore Size:90 Å
Guard Column:Raptor Polar X guard column cartridge 5 mm, 2.1 mm ID, 2.7 µm (cat.# 9311A0252)
Temp.:35 °C
Standard/SampleSpinach extract
Inj. Vol.:2 µL
Mobile Phase
A:Water, 0.5% formic acid
B:Acetonitrile, 0.5% formic acid
Time (min)Flow (mL/min)%A%B
0.000.53565
5.00.59010
6.50.59010
6.510.53565
80.53565
DetectorMS/MS
Ion Mode:ESI-
Mode:MRM
InstrumentUHPLC
Sample PreparationFrozen spinach was added to a Blixer processor with dry ice (3:1-4:1 ratio) and then ground into a very fine powder. The homogenate was placed into the freezer immediately. A 5.0 gram sample of the spinach powder was weighed into a 50 mL centrifuge tube (cat.# 25846). According to the QuPPe method (Quick Polar Pesticides Method), 5.0 mL of methanol with 1.0% formic acid was added into the centrifuge tube. The tube was shaken by hand for 1 min and then by a mechanical shaker vigorously for 5 min. After centrifuging for 10 min at 4200 rpm, the supernatant was filtered through a 0.22 μm filter (cat.# 23984). The final extract was fortified with the AMPA, glufosinate, and glyphosate at a final concentration of 100 ng/mL.
FSFA3215-CN