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薄层层析是五十年代末期发展起来的一种分离方法。由于它有设备简单、需样量少,分离效果好,在某些特定条件下不需标准品等特点,因此在各个领域中都得到了广泛的应用。在农药的分离测定中,薄层层析同样是一种有效的方法。尤其对某些热稳定性差,不宜直接用气相色谱法测定的农药品种,更显现出它的优越性。 物质纯度测定系对高含量主成分的定量。在高含量化合物的测定中,要提高测定结果的精确度,除要选择出优惠的薄层层析条件外,由于含量高、点样少,因而点样的准确度即成为结果误差的主要来源之一。在薄层定量工作中一般均采用定体积点样方式(即用移液管、微量注射器、定容毛细管等容量仪器取一定体积的稀释样液点于板上)。这种点样方式的准确度取决于所使用容量仪器刻度的准确与否及操作者的熟练程度,操作稍有不慎即会引进较大误差。
Thin layer chromatography is a separation developed in the late fifties. Because of its simple equipment, sample less, separation effect is good, under certain conditions without the need for standards and so on, so in all fields have been widely used. In the separation and determination of pesticides, TLC is also an effective method. Especially for some poor thermal stability, it is not suitable for direct determination of pesticide varieties by gas chromatography, but also showed its superiority. Material purity determination of the high content of the main component of the quantitative. In the determination of high content of compounds, to improve the accuracy of measurement results, in addition to the selection of preferential thin-layer chromatography conditions, due to the high content, less sample, so the accuracy of the spot to become the main source of error results one. In the quantitative work of the volume are generally used fixed-volume spotting way (that is, using pipette, micro-syringe, volumetric capillaries and other volumetric instruments to take a certain volume of diluted sample spot on the board). The accuracy of this sampling method depends on the capacity of the instrument used to determine the accuracy and operator proficiency, the operation is a little mistake that will introduce greater error.