Multi-functional on-line chromatographic split-flow sample injection method

Abstract

The invention provides a multi-functional online chromatographic split-flow sample injection method. A split-flow control device used in the method comprises a sampling valve box, a six-way valve, a shunt, a trapping trap and an electronic flow controller. Samples collected by the six-way valve and a quantitative loop are carried by carrier gas to enter the shunt and are divided into two parts by the shunt, one part enters a chromatographic column to be analyzed, and the other part passes through a shunting outlet, is adsorbed by the trapping trap and then is emptied by the shunting valve. The calculation formula of the shunting ratio is as follows: total flow: flow of the chromatographic column. The multi-functional online chromatographic split-flow sample injection method is wide in used temperature range, selectable in enrichment filler and high in universality, and covers conventional chemical product analysis and sample and solvent analysis of food grade / medicine grade / polymer grade and special material gas. The device can be directly mounted in a sample injection valve box, so that the mounting and maintenance convenience is greatly improved. A separation pad, separation pad purging, a shunting inch pipe and the like are not needed, so that the cost is greatly reduced.

Description

Technical field[0001]The present invention relates to analytical instruments, and more particularly to a multifunctional online chromatographic splitting method.Background technique[0002]Chromatographic split injection technology is one of the key technologies that improve online chromatography analysis, improve chromatographic separation and detection limit. On the other hand, the analysis of environmental (atmospheric, water and soil) pollutants and high purity samples and solvents (food grade, pharmaceutical and chemical polymerization levels, etc.), due to extremely low detection limits for trace and ultra-trace impurities, The detection limit of the routine analysis method has not been achieved, and the splitting has caused less samples to enter the detector. To resolve this contradiction, the usual technical means is to increase the pre-processing equipment for sample pre-concentration, concentrate the original sample, turn into a constant component and then subtractive analys...

AI Technical Summary

Problems solved by technology

Online preprocessing equipment, due to the different analysis requirements of various industries, has poor versatility, is currently not mature, and the market is relatively narrow. Generally, large instrument companies are unwilling to invest too much in research and development, while small and medium-sized instrument companies have limited research and development capabilities and funds. Relatively insufficient, resulting in not only expensive pretreatment equipment, but also a series of problems such as weak performance, poor versatility, inconvenient installation and connection, and high repair rate

[0003] At present, most of the online chromatographic analyzers still use the split inlet of the laboratory chromatograph. Although there is no problem in performance, there are still many problems: such as the convenience of installation, connection and maintenance, the increase of temperature control points, and the cost. higher

The split inlet of the laboratory chromatograph is generally installed above the chromatograph, which makes the installation and connection between the inlet and the online sampler extremely inconvenient, and it is time-consuming and laborious to remove the online sampler for maintenance; Temperature control leads to too many temperature control points of the chromatograph; and the heat preservation at the connection between the split inlet of the laboratory chromatograph and the online sampler is difficult to handle, and it is also difficult to remove during maintenance; in addition, the split injection controller used for online chromatographic analysis, There is no need for parts and consumables such as injection septum, septum purging and splitter tube, which not only increase the cost, but also bring great inconvenience to maintenance and replacement