Spotting needle of thin layer chromatography

Abstract

The invention discloses a spotting needle of thin layer chromatography, belonging to the field of experimental apparatus. The spotting needle comprises a needle tube and a needle head, wherein the needle head is provided with a baffle plate at a position near a needle point and passes through the baffle plate, a position where the needle head contacts with the baffle plate is sealed, and the baffle plate is 1.5 to 2.5 mm away from the needle point. During usage, when a to-be-spotted tested solution is pushed out from the needle tube to the needle head, the liquid does not rise across the baffle plate due to the obstruction of the baffle plate, so that all the to-be-spotted tested solution can be spotted onto the thin layer plate, and such phenomenon can be overcome that part of the solution rises along the outside of the needle point and then quickly evaporates due to capillarity and thus part of reference substances or reference medicinal materials dissolved in the solution are adhered at the outside of the spotting needle but cannot be spotted onto the thin layer plate. Therefore, the spotting amount is ensured to be accurate and thus the detecting result is ensured to be accurate.

Description

technical field [0001] The invention relates to a chemical experiment instrument, in particular to a sampling needle. Background technique [0002] Thin-layer chromatography is a typical qualitative experimental technique in the fields of chemistry and medicine, and capillary tubes are generally used for sample application. At the same time, thin-layer chromatography is also used as a semi-quantitative technique. At this time, a sampling needle is generally used for sampling. In practical applications, micro-samplers are often used, such as injection needles for high-performance liquid chromatography (such as figure 1 shown). [0003] When this type of sampling needle is used for sample pointing, when the test solution to be sampled is pushed out from the needle tube to the needle tip, due to the capillary phenomenon, part of the liquid tends to rise to the needle along the outside of the needle tip, while the test solution The solvent is usually a volatile solvent such a...

AI Technical Summary

Problems solved by technology

[0003] When this type of sampling needle is used for sample pointing, when the test solution to be sampled is pushed out from the needle tube to the needle tip, due to the capillary phenomenon, part of the liquid tends to rise to the needle along the outside of the needle tip, while the test solution The solvent is usually a volatile solvent such as methanol, so the part that rises to the needle will evaporate quickly, so that the dissolved part of the reference substance or the substance to be tested (such as the reference medicinal material extract) adheres to the outside of the sampling needle, while The sample cannot be placed on the thin-layer board, which affects the accuracy of the sample amount and the accuracy of the test result

Even when performing qualitative testing, if the absorbed sample cannot be completely applied to the thin-layer plate, it may result in the need to draw multiple samples for effective application, which is very troublesome

Images