Syringe filters can be for in HPLC analysis and IC analysis, and filtering the sample solution, and is an important step in the sample pretreatment process. Here is a brief introduction to HPLC analysis with syringe filters :
A brief introduction to HPLC:
Liquid chromatography (HPLC) is an analytical method. In recent years, it has been widely for the separation and determination of functional components of healthy food, nutritional fortifiers, vitamins, and proteins. The HPLC can analyze organic compounds.
The separation efficiency of HPLC is higher than that of ordinary liquid chromatography, and appeared many new stationary phases in the development process, which greatly improves the separation efficiency.
High sensitivity: High-sensitivity detectors have been wide for liquid chromatography, which further improves the sensitivity of the analysis.
High speed: The flow rate of the mobile phase in the column is much faster than that of classical chromatography, generally reaching 1-10ml/min.
High pressure: Liquid chromatography uses liquid as the mobile phase. The liquid flows through the chromatographic column and is subject to great resistance.
Wide range of applications: Compared with gas chromatography and liquid chromatography, although gas chromatography has the advantages of good separation ability, high sensitivity, fast analysis speed, and convenient operation
And limited by technical conditions and the boiling point is too high. or substances with poor thermal stability are difficult to analyze by gas chromatography.
On the other hand, make the sample into a solution without vaporization, so it is not limited by the volatility of the sample.
For organic substances with a high boiling point, poor thermal stability, and large relative molecular weight (more than 400) (these substances account for almost 75% to 80% of the total number of organic substances), liquid chromatography can be for separation and analysis in principle.
Precautions for using syringe filters in HPLC analysis:
What are syringe filters used for:
In HPLC analysis, the particle size of chromatographic column packing is small and easily blocked by impurity particles, so need pre-filtered samples and solvents to remove particulate contaminants and protect the instrument.
Ion chromatography commonly used in environmental analysis also requires that cannot introduce inorganic pollutants in sample pretreatment, so often use syringe filters.
How to use syringe filters:
When the syringe filters the solvent with pigment, should verify experimentally and should select the filter membrane, which does not absorb all the pigments.
Strictly select a suitable filter membrane. The sample solution is an organic phase and should choose an organic filter membrane.
For the aqueous phase, selected a special filter membrane for the aqueous phase. There are marks on the filter membrane box, so pay attention to distinguish them.
And pay attention to the bag and seal, and ensure that the gloves and tools are clean. Cross-contamination is the most difficult thing to solve and the most difficult thing to deal with.
The process of using the syringe filters, such as nylon syringe filters, should not be too hard, so as not to break the filter membrane and lose the original filtering effect.
Some sample solutions with complex matrices, especially removed those in which fats or macromolecular proteins, or emulsified solutions, will be particularly difficult to pass through the membrane, blocking the filter membrane, and the filtration will not move. At this time, you should replace it with a new one and filter it again.