The pretreatment of what project is suitable for using SPE solid-phase extraction technology, that is, SPE solid-phase extraction is more ideal than ordinary solvent extraction. Generally, there are the following situations.
Such conventional treatment is basically shaking extraction with a water-immiscible organic solvent. The advantages of using SPE solid phase extraction are:
(1) The pretreatment process can be repeated quantitatively
The operation of solvent oscillation is generally only required to control the time, but cannot control the oscillation frequency, intensity, and action. We know that each person's oscillation action is different, and it is difficult to ensure a consistent action even for the same person. Therefore, the action of solution extraction is not quantitative and cannot be repeated. In the application of SPE solid phase extraction, it is easier to maintain the uniformity and stability of the column and elution speed. Therefore, the extraction process of solid phase extraction can be repeated and quantitative.
(2) On-site processing
The analysis of organic matter in water has a long-standing bottleneck. That is, organic matter can remain relatively stable in ponds, reservoirs and other environments, but once it enters the small environment of the sampling bottle, it will change rapidly. Therefore, many organic matter analysis methods of water require instant analysis, which can not exceed 4 hours at most. In general, the time from taking the water back to the laboratory is far more than 4 hours, the sample has changed, and the reliability of the analysis results can be imagined.
If the SPE solid phase extraction technology is introduced, due to its simple equipment, small size and easy portability, it is possible to perform pretreatment while sampling on site. The sampler brought back to the lab a solid-phase extraction cartridge, not a water sample. This ensures that we are dealing with truly compositionally stable water samples. In terms of practical application, there is still considerable work to be explored to replace traditional liquid-liquid extraction with solid-phase extraction technology in water detection. At present, it cannot be completely replaced, but its development prospect is worth looking forward to.
(3) Reduced consumption of organic reagents
When processing water samples, if solid-phase extraction is used, only organic solvents need to be used in elution, which is more than ten times less than traditional liquid-liquid extraction. It has positive significance for the personal protection and environmental protection of the experimenter.
This is a relatively successful example of SPE solid-phase extraction in practical applications, mainly referring to the pretreatment of blood and urine samples in hospitals. Since the adsorption of drug components is the advantage of SPE solid-phase extraction, coupled with the single sample, the composition is fixed, well suited for large-scale batch purification operations after the method is determined.
The ideal state of extraction is specific enrichment or specific exclusion, but whether it is solution extraction or solid-phase extraction, it is basically similar and compatible, and at most it can achieve extraction at a "certain type" level, but cannot achieve "a certain type of extraction". A" level of extraction. On the basis of the solid-phase extraction column, the immunoaffinity technology can be used, and its biological specific selective adsorption can be used to achieve a perfect extraction close to the theory. The practical difficulty is that although the concept is good, there are fewer applications available due to the relatively high technical difficulty.