Large-volume sampling-dual solid-phase extraction-high performance liquid chromatography on-line combined equipment

Abstract

The invention relates to online LVI (large volume injection)-double SPE (solid phase extraction)-HPLC (high performance liquid chromatography) combined equipment. The equipment comprises three chromatography pumps, an automatic LVI device, an automatic injection device with ordinary injection quantity, a high-pressure ten-way switching valve, two SPE columns, a column heater, a chromatographic column and a detector. By the aid of the combined equipment, the simplest hardware equipment is connected with a flow path, direct injection of large volume liquid samples larger than 1 mL is allowed, two SPE columns for parallel treatment are arranged and combined with the HPLC to perform overlapped injection, pretreatment and separation, the occupied time of single sample in the whole batch of treatment samples is greatly shortened, besides, the combined equipment can be conveniently switched into an ordinary HPLC system, and free switching between the online system and an ordinary separation system is realized.

Description

technical field [0001] The invention belongs to the field of analytical chemical sample pretreatment, and specifically relates to the design, analysis and application of a large-volume sampling-dual solid-phase extraction-high performance liquid chromatography on-line equipment, which is suitable for trace amounts in liquid samples in the environment and food Injection, online extraction, enrichment, impurity removal, desorption, separation and detection of organic matter. Background technique [0002] For the analysis of trace compounds, there are generally two strategies: small-volume sampling (such as biological samples), detection with high-sensitivity detectors; or large-volume sampling (such as environmental samples), enrichment and removal of impurities before sample analysis. [0003] For the analysis and detection of environmental samples, such as trace pollutants in water, the sampling volume and injection volume can usually be increased, and then solid phase extra...

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Problems solved by technology

[0005] However, the online combination of solid-phase extraction and high-performance liquid chromatography has two limitations: one is that the injection volume is small, generally less than 1mL, and the sample needs to be manually concentrated offline before injection; The time for sampling and processing samples and the time for HPLC to separate target objects are relatively long, resulting in prolonged analysis time

The existing on-line solid phase extraction system usually uses a six-way switching valve to connect a single solid phase extraction column, through the switching of the six-way switching valve, the conversion between the two states of sample loading extraction and desorption separation is realized; in addition, the general sampler The injection speed is about 1mL / min. If the injection volume is as high as several milliliters or even tens of milliliters, the injection time will be difficult to ignore. In addition, the solid-phase extraction column also needs activation, impurity removal and equilibration time. The entire analysis time will be very lengthy and the throughput of the analysis will be greatly reduced

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