LC-2900 liquid chromatography instrumentThe operation is both intuitive and convenient. The LC-2900 liquid chromatograph can input all control information through the instrument's own keypad without connecting to a computer, and all operations are displayed on the LCD screen. The LC-2900 liquid chromatograph can also be connected to a computer and use workstation software. There is no secondary analog-to-digital conversion between this workstation and LC-2900 liquid chromatograph, and pure digital communication is used. The data read in are all direct two channel sampling data without any processing, and there is no signal distortion. This ensures sampling accuracy and data loss during post-processing. The LC-2900 liquid chromatograph has a sampling accuracy of 18 digits (0.1 seconds/time).

LC-2900 liquid chromatography is an instrument that utilizes the difference in the distribution ratio of a mixture between liquid-solid or immiscible liquids to separate the mixture first, and then analyze and identify it.LC-2900 liquid chromatography instrumentWidely used in fields such as biochemistry, biomedicine, environmental chemistry, and petrochemicals. What are the common malfunctions of LC-2900 liquid chromatography instrument in use? How to handle?

1. High column pressure.

Reason: Salt deposits in the buffer solution inside the column; Or sample contamination deposition.

Measure: If salt deposits in the buffer solution inside the column, rinse the column with pure water at 40-50 ℃ at low speed and gradually increase the flow rate. After the column pressure drops significantly, rinse it with pure water at room temperature, and then rinse the column with pure methanol for 30 minutes.

If it is caused by sample contamination deposition, rinse the column with pure water in reverse, then rinse with methanol, followed by rinsing with methanol+isopropanol (4+6), then rinse with methanol, then rinse with pure water, and finally rinse the column with methanol in forward direction for 30 minutes.

2. Bubbles overflow.

Reason: The main reason is that the filter * is immersed in buffer solutions such as ammonium acetate, causing internal mold growth and forming bacterial colonies that block the filter.

Measure: Soak the filter in a 5% nitric acid solution,LC-2900 liquid chromatography instrumentUse ultrasonic cleaning for minutes. Alternatively, soak the filter in a 5% nitric acid solution for 12-36 hours, then clean it with pure water. Turn on the purge button to clean and degas until no bubbles emerge. Open the pressure relief valve, turn on the pump, and rinse the filter with pure water for about 1 hour.

3. No pressure indication or liquid flow.

Reason: Wear of pump sealing gasket; Or bubbles may enter the pump body.

Measure: Replace the sealing gasket or use a 50ml glass syringe at the pump outlet to assist in extracting air.

4. Large pressure fluctuations and unstable flow.

Reason: There is air in the system or foreign objects between the gemstone ball of the one-way valve and the valve seat.

Measure: Observe the amount of mobile phase, and fully degas the mobile phase. If the one-way valve and valve seat cannot be sealed, remove the one-way valve and place it in a beaker containing acetone for ultrasonic cleaning.

5. Poor peak output, peak branching.

Reason: The chromatographic column is contaminated or the column head packing collapses.

Measure: If the chromatographic column is contaminated, it needs to be cleaned. If the column head filler collapses or hardens, remove the hardened part and replace it with new filler. Repeatedly drip methanol and press the stainless steel rod tightly until it is filled. Wash the column head clean with methanol.

6. The repeatability of peak area is poor.

Reason: Leakage of injection valve; Either the sample needle is not in place, or the liquid volume is insufficient.

Measure: Replace the gasket of the injection valve. If the sample injection needle is not in place, insert it to the bottom. If the liquid volume is insufficient, the sample solution must be injected and quickly and smoothly transitioned from the LOAD state to the PROJECT state. Avoid injecting overly concentrated sample solutions.

The LC-2900 liquid chromatograph can be directly composed of a high-pressure constant flow pump and a UV detector to form an isocratic analysis system. The LC-2900 liquid chromatograph can also use a workstation to simultaneously control several high-pressure constant flow pumps, UV detectors, and constant temperature column boxes,LC-2900 liquid chromatography instrumentImplement functions such as multiple high-pressure gradient elution and wavelength scanning.