The resolution of the liquid chromatography column is low, how to improve the resolution of the gas

According to your question: whether it is a high-purity sample or a low-purity sample, after injection, the results obtained are very pure, basically 99%; Suffice it to say, the injected sample is not separated at all, and you basically just see a chromatographic peak on its chromatogram, indicating that your sample separation conditions have not been selected well. Normally, the separation conditions for the LC analysis of the sample can be found in the literature, as long as you strictly follow the separation conditions in the literature, you can get good resolution, unless the column you are using has been severely degraded.

With suitable chromatographic conditions, the following points should also be noted: 1. The injection amount of the sample; The lower the injection volume under the same conditions, the higher the column efficiency. 2. Column temperature; Under the same conditions, the higher the column temperature, the higher the column efficiency.

3. Pay attention to the pipeline connection between the chromatographic column and the instrument; The finer the tubing, the smaller the dead volume, which can improve sample resolution (it is recommended to use the manufacturer's connection kit whenever possible). 4. Strictly grasp the proportion of mobile phase; The ratio of the mobile phase is a key factor in controlling sample elution.

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You're talking about capillary columns.

The two most important influencing factors are: 1) column coating, 2) column temperature.

First, select the appropriate column according to the object you want to analyze, and then optimize the column temperature conditions to achieve a satisfactory separation, generally using a temperature program.

Hope it helps.

This can be done by adjusting the mobile phase ratio, adjusting the pH of the mobile phase, changing the column to another brand, and increasing the length of the column.

1. Adjust the mobile phase ratio: the chromatographic column used for detection has a higher theoretical plate number, which can provide better resolution, so as to have a greater possibility of separation of possible impurities; The ratio can be adjusted by adjusting the flow rate and reducing the injection volume at the same time;

2. Adjust the pH value of the mobile phase: the pH value of the mobile phase can change the retention time and resolution of the sample; A change in the pH value of the mobile phase can even change the order of peak generation of some samples in a dry state; The pH value of the mobile phase can change the peak height of the sample, that is, the peak shape can be adjusted by guessing the beat;

3. Replace other brands of chromatographic columns: use the color spike spectrum columns produced by other manufacturers for use testing;

4. Increase the length of the column.

The resolution (r) is calculated as follows: r 2[t(r2)-t(r1)] w1 w2 ).

1. t(r2) is the retention time of the latter peak in the two adjacent peaks;

2. t(r1) is the retention time of the first peak in the two adjacent peaks;

3. W1 and W2 are the peak-bottom widths of the two adjacent peaks.

This one needs to be tried.

First of all, if the retention time of the two substances in the liquid phase is very close, the organic phase ratio can be adjusted. If the organic phase is reduced, the two peaks may be pulled apart. You can also consider setting up a gradient method, which will make the peak run better, and then separate the two species.

Then, you can also consider adjusting the pH value of the aqueous solution, which depends on the pH of the substance. If both are neutral substances, then the meaning of adjusting the pH value is not played.

Liquid phase: Usually any gas can be infinitely mixed, so no matter how many gases are contained in the system, it is one phase, called the gas phase. A homogeneous solution is also a phase known as the liquid phase.

Resolution, also known as resolution, is often used as an indicator of the total separation efficiency of the column in order to determine the separation of the separated substance in the column. Denoted by r. r is equal to the ratio of the difference between the retention times of adjacent chromatographic peaks and the mean peak widths of the two chromatographic peaks.

The ratio of the difference in retention time between the two peaks of the adjacent band to the average peak width. Also called resolution, it indicates the degree to which two adjacent peaks are separated. The larger the r, the better the separation of the two adjacent components.

Summary. Hello, I think it's still a problem with the column. If the column is used for a long time, the column efficiency will be reduced, which will affect the resolution, and the improvement method is to replace the column with a new one.

If it's a new column and the resolution isn't good, you can use a longer column, which will increase the resolution.

Hello Zhou Qihao, I am happy to answer for you The resolution in HPLC is 0, you can change the column or increase the flow rate a little. I hope my reply will be helpful enough to help you, and I wish you a happy life, thank you!

Looking at the picture, it's definitely not 0.,What's wrong?。

Hello, I think it's still a problem with the column. If the column is used for a long time, the column efficiency will be reduced, which will affect the resolution. If it is already a new column and the resolution is not good, then you can use a longer column to increase the resolution.